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FAQs on Freshwater Stingray Foods/Feeding/Nutrition

Related Articles: Freshwater Stingrays,

Related FAQs:  Freshwater Stingrays, FW Stingray Identification, FW Stingray Behavior, FW Stingray Compatibility, FW Stingray Selection, FW Stingray Systems, FW Stingray Disease, FW Stingray Reproduction,

Water temp... warm... Water quality: Soft, acidic... Lack of boisterous tankmates? When in doubt, patience...

Skinny Stingray    4/21/18
My motoro stingray is a pretty active stingray but parameters in the tank are normal (no nitrates, nitrites, ph levels are normal)
<I would prefer the values rather than a statement! To recap, nitrite should be zero of course, and nitrate as low as practical, though zero nitrate is in practical terms very difficult to achieve. If you are honestly getting a zero reading for nitrate, I'd double-check you're using the test kit right, because a zero nitrate reading in a tank with a large,
predatory fish is so unlikely. While the precise pH value isn't critical, it should be stable and not too high, and ideally, hardness and pH would be towards the soft water end of their respective ranges; maybe 2-15 degrees dH, pH 6.5-7.5.>
and there is no chance of infection or parasites.
<How can be you be so sure? Even at the retailer there's some risk of exposure.>

There are constant water changes and filter changes with at least 25% changed. He is fed everyday or every other day with more food (this does not happen often, but there are issues that come up as they do in life, but not enough for there to be leftovers in the tank).
He has been in our tank for over a year and a half and has been growing steadily, so we are pretty sure there is no stress, and as he has survived this long and continues to grow.
<I agree, this is promising.>
Our substrate is a soft gravel that My parents used years ago with another ray who lived a long life (obviously rinsed thoroughly with water).
<I am sure you're aware of the debate surrounding the use of substrates in ray aquaria. There are arguments in favour of soft sand substrates, and arguments in favour of no substrate at all. I wouldn't say it comes down to personal taste, but the latter approach is perhaps easier and safer.>
He is a very happy ray in all searching through gravel, finding Blackworms, swimming around all normal ray things. My problem is that he is too skinny.
He is fed a good diet of shrimp, Blackworms and live fish (who have been quarantined by fish store for at least a month usually more) but he will not gain weight.
<Live fish is already one major risk factor. Let's be clear, unless you're home-breeding thiaminase-free fish from parasite-free parents, then any live fish are dangerous. End of story. For a start, cyprinids (goldfish, minnows, and their relatives) contain thiaminase and simply should never be used as live food. No scientifically sound argument can be made in favour of using those types of fish, and store-bought "feeder" goldfish and minnows are simply parasite-bombs. If you've used those, then right there is one very probable reason for the ill-health of your Stingray. Thiaminase is an enzyme that breaks down thiamin (vitamin B1) and when used regularly the predatory fish can/will develop all sorts of vague, but potentially lethal, health issues. There's a BIG scientific literature out there on this subject, but let me direct you to Marco Lichtenberger's summary here at WWM, written specifically for aquarists:
Next up, the feeder fishes bought at pet stores will almost certainly have parasites of some sort in them, and quarantining them only means those parasites aren't killing the host fish. Get those feeders inside your predatory fish and things become more complicated. A goldfish might, for example, have a degree of resistance to a certain parasite because they evolved together over thousands if not millions of years, but South American Stingrays may never encountered parasites common in Eurasia, and would have no resistance at all to that parasite. Do you see the problem here? It's not a definite explanation, but the use of feeders is just such a wildly risky chance to take, that it is very difficult to rule them out. Given Stingrays aren't obligate fish-eaters in the wild, there's no real reason to feed them live fish anyway, and most if not all experienced Stingray keepers and breeders avoid them. Instead focus on invertebrates, particularly worms, as well as more mixed, vegetable-rich food items that offer vitamins and fibre. Gut-loaded earthworms and river shrimps are a good way to get vegetables into your Stingray! Alongside these, a good
quality Stingray pellets will help round out their diet, and arguably could make up their entire diet if you're on a budget.>
He also completely refuses to eat things like smelt, nightcrawlers and even wild caught shrimp (as in once he smells it on your hand he will not come near you the rest of feeding time he hates them that much) and we have tried countless times to introduce him to other foods.
<The golden rule with fish remains this: they'll eat when they're happy and healthy. If they're not eating, it usually means there's a problem. It's very rarely the food itself that's wrong, but something else. Could be water quality or chemistry, could be the lighting (Stingrays hate bright light), could be the tankmates, if any (Stingrays are best kept alone). But as we've discussed, there could be a deeper problem if live feeders have been used, especially goldfish or minnows. Nobody keeping a fish as valuable and as delicate as a Stingray should be giving them live feeder fish.>
We have even hidden some in the foods he does enjoy and he spits out the food he doesn't like once he figures out it is there.
<Classic food refusal.>
He is too skinny but as I said he is still growing outwards so he is still healthy but I hate seeing him so skinny.
<I would be thinking along the lines of internal parasites, if he "eats but stays thin" but I'd also be worried about thiamin deficiency.>
Are there any fattening foods that I can safely feed a ray?
<See above; your Stingray doesn't need more calories, but he does need his appetite back. You need to review that aspect, and act accordingly.>
I've seen people suggest clams, muscles, and worms.
<Clams are good. Mussels can be used sparingly -- again, they contain thiamine. Earthworms are good and safe; bloodworms and especially Tubifex worms substantially more risky, and best avoided.>
We can try other fish but I'm not sure how he will react. Any tips or suggestions will be much appreciated!
<Hope this helps. Cheers, Neale.>

Re: Stingray.... sys., fdg.       8/8/15
So does this sound like a good routine? Im sorry with the so many questions, I just want this to be a success.
A 15% water change weekly
<No enough. 50% weekly is mean, when it comes to Stingrays. The more the better. Expect to spend several hours per week on maintenance. Keep the Stingray alone in the big tank and you might be fine with 50% weekly. Every extra jumbo fish doubles your workload. I am NOT a fan of adding tankmates to Stingray aquaria. No benefits at all to doing so.>
And then I am a big fan of Kordon's water conditioner, the zero Nitr/ite/ate (both) and zero ammonia.
<Let us be crystal clear about this. Water conditioners neutralise these chemicals IN TAP WATER. They do NOTHING, ZILCH, NADA, for the dissolved metabolites produced by your fish. That's the job of the filter, water changes, and optionally fast-growing plants under intense lighting. An analogy: bleach and antibiotics both kill germs. But they both have
different jobs and you wouldn't drink bleach to treat a sore throat!>
This is just to be sure nothing hurts Gizmo, my ray. It is also stingray and delicate fish and plant safe.
Food will be assorted live, frozen and pellet including Massivore, sinking carnivore, live declawed crayfish, in house bred minnows,
<No. You will NOT be using these if you are sensible. Minnows contain Thiaminase, and that's a major health problem for predatory fish. Please, will someone tell me for the love of all that is holy, why Americans still use feeder fish? Has been obsolete in the UK since at least the 80s. There are no benefits to using feeders except in extreme cases (such as South
American Leaffish) where the predator will flat refuse anything else.
Feeder fish otherwise are nothing but a string of health risks and behaviour risks.>
blackworms earthworms and lastly snails.
<Please do read Richard Ross on Stingray feeding. They're super-easy to feed properly; settle them in with earthworms and possibly a few gut loaded river shrimp, and once settled, switch to safe frozen and pellet foods.
They are greedy fish, easily starved, and need a couple of substantial meals per day, which is one reason why cohabiting with other species causes problems: it's harder to ensure they're getting enough to eat, and all that extra food dumped in the tank increases the amount of ammonia the filter has to process. The most economical route is frozen seafood, biased
towards those foods without Thiaminase (little/no shrimps and mussels, but plenty of cockles, lancefish and tilapia fillet). Do read: http://www.wetwebmedia.com/ca/volume_6/volume_6_1/thiaminase.htm
Consider the use of a vitamin supplement too.>
School of silver dollars (6)
My gar temporarily (1)
1 Cichla ocellaris grow out (1)
Thank you for all your help
<As Bob would say, "Keep Reading". Cheers, Neale.>

Sting Ray picky eater   3/23/13
Dear WWM Crew;
I have a juvenile male Potamotrygon reticulata ray that will only eat small feeder shrimp (I kill the shrimp first and then present them to him with metal tweezers). The ray readily eats the freshly killed shrimp but will not eat any other food source I have tried to feed him (small chopped up bits of frozen fish, shrimp, prawn, squid, octopus or blood worms that have thawed). I have tried these either food types either plain or soaked in aquarium grade garlic extract. I haven't tried earth worms yet, as the ground is still frozen here in Canada. I am aware that there are nutritional problems in eating only shrimp. Also, live shrimp get expensive, and it will only get worse as the ray gets bigger (current diameter 4 inches). What can I do to get my ray to eat other food types?
When I first got the ray, I tried only blood worms and frozen food for 2 weeks with no luck before discovering the live shrimp, and I think it never ate that entire time.
[Tank = 125 gallon; tank mates = small Neotropical cichlids, tetras, silver dollars; tank fully cycled and water quality good; pH = 7.6 to 7.8, temp = 79 to 82; biweekly water changes of 30%; substrate = pool filter sand]
<Hello Jason. Live shrimp is an okay food for Stingrays but unless gut-loaded first, they shouldn't be used exclusively. Yes, earthworms are a very good food, and most Stingrays go for them without any encouragement.
Because they contain plant material in their guts, earthworms are a nutritious food, and being terrestrial animals, the chances of them carrying any parasites that could cause harm to fish is practically nil.
They are difficult to find outdoors in winter if you don't have a compost heap, so one option is to rear your own indoors in a basement or garage, which is easily done using widely sold earthworm "wormery" kits (or you could knock something together using plans found online or in an earthworm-rearing book). Practically a hobby in itself, there's a great book about earthworms called "The Earth Moved" by Amy Stewart that'll give anyone with even a slight interest in nature a lot of pleasure. You can also buy earthworms at bait shops catering to anglers. Stingrays aren't normally fussy feeders in the wild or captivity, and should eat all sorts of things including the seafood you've suggested. Frozen lancefish cut into bite-sized chunks are another excellent food, and you can substitute this with any white fish you happen to be cooking for yourself, such as cod, Pollack or tilapia. Some experts also use small amounts of beef heart and beef liver, the latter in particular providing useful vitamins, but I'd use these sparingly, no more than 10% of the food used. Do also keep any food offered small enough to swallow; Stingrays don't appreciate very large chunks of food, so err on the size of small rather than big pieces of food.
However, a bigger issue with Stingrays isn't so much what they'll eat but making sure they're happy enough to be hungry. Like cichlids and puffers, Stingrays have huge appetites when settled, but for a week or two after purchase they may be too insecure to be hungry. Beyond that first week or two, Stingrays normally settle down well, but if it still doesn't feed, review living conditions. Water quality is the key thing, but also ensure there's a good turnover of water in the tank, especially from top to bottom, so oxygen is thoroughly distributed. Keep an eye out for tell-tale signs of stress like hyperactivity, lethargy and odd swimming positions such as swimming into the filter stream or hovering about at the top of the water. If your Stingray is eating just one food but ignoring other (non-live) foods, then just stop feeding the live food -- after a few days, hunger will ensure the Stingray tries the other foods on offer! Don't be afraid to starve a healthy (i.e., well-fed and chunky) Stingray for a week or two! Cheers, Neale.>
Re: Sting Ray picky eater    4/2/13

Hi Neale,
Thanks for the advice. The ground has now thawed, and my ray is happily eating earthworms. I will try cultivating them like you suggested. The ray still will not eat frozen seafood (even though I cut it up into small bits). I will try the starve method to get it onto frozen food as soon as it puts on some weight.
You mentioned unusual behaviour. My ray was swimming into the strong current in the filter stream at the surface for about 20 hours a day for a total of 5 days. This was about a week after I introduced it into the tank.
<Not unusual immediately after purchase, but beyond the first week or two, you'd expect most fish to have settled down -- assuming their new home was adequate.>
At this point nitrites were a bit high, and I hadn't yet fed the fish any live foods, so it hadn't eaten. The ray stopped swimming into the filter stream the moment I fed it live food. However, this also coincided with when nitrites in the tank fell to 0. As such, I cannot be sure if it was water chemistry or feeding that made the ray happy with living on the bottom again. So why did the ray swim into the filter current?
<See above. Swimming into a current "feels" like swimming away from wherever you are, which makes sense if you're an unhappy fish anxious to get somewhere better and/or familiar. Of course, it can also mean a fish has a migratory instinct (Colombian Shark Catfish likely swim into filter currents because of this) or else needs oxygen-rich water lacking in the tank generally (you'll see this behaviour among the more picky stream-dwelling fish such as Otocinclus and Hillstream Loaches).>
At first I was alarmed. I thought it might be improper oxygen levels in the water, or perhaps due to the purer state of the water coming out of the filter. However, I have read that other people have had rays which like to play in bubbles and current. What do you think of that theory?
<As good as any. Likely no single explanation for all Stingrays in all aquaria.>
It was beautiful to watch the ray swim and I miss this behaviour.  The ray still occasionally goes up the glass and appears to gulp air at the surface. None of my other fish appear to experience any oxygen related issues, so I haven't been alarmed. Should I be?
<Not really. It seems pretty common for Stingrays to surface periodically, in captivity at least. If otherwise healthy and feeding well, don't worry too much.>
<Have fun! Neale.>

FW Ray fdg.   9/13/2011
Hey guys quick question
I feed my motoro this AM and tonight she pooped out a part of undigested night crawler that was feed to her in the AM should I be concern? This has never happen to any of my rays. Thanks again
<This is not unusual and not a problem. Cheers, Neale.>

What could be wrong ? FW rays... upset, non-fdg., NO3   9/1/11
Hello again my friends. just got over a hurricane Irene(sun). My stingrays were on air pumps for 15 hours till I got a generator (Mon) that night the bigger ray ate great smaller female had one piece of krill . Yesterday I fed them and they both ate krill put female was not acting like herself she would sit in one spot and be raising her front lip like she was sniffing today she didn't want to eat at all I don't know if she is just
stress by the whole ordeal . I tested the water they were : 6.8-0-0-30.
The readings have always been this since she's been in the tank had her a yr my male I had for 4 yrs they got two hang on filters and a canister that's for a 300gal tank hope you guys can help
<Hello Maria. Don't feed the fish for a few days. Review water chemistry, and make sure it's where it should be. Review water quality, and if necessary, do a water change. Check the filter is working properly. Dim the lights. If the filter was switched off for 15 hours, there's a good chance the filter bacteria are stressed. Assume the worst, and reduce feeding and increase water changes for at least the next couple of weeks. That'll give time for the filter to recover. Do also check the temperature is correct.
Cheers, Neale.>
Re: What could be wrong ?  9/1/11
I did do a 20% water change yesterday I will I only feed them once a day every other day so I will just keep it to light or no feedings all the filters are working fine nothing broke all working strong I will keep an
eye on water quality and such and I will do another water change soon. But y would it only effect her and not the other ray and other tetras I got in the tank?
<It's a complicated world, Maria. Sometimes one fish reacts differently to a power outage than another fish in the same aquarium. All you can do is be patient, observe carefully, check water quality, and hope for the best.
Dimming the lights will reduce stress, and hopefully the ailing fish will perk up. Use an airstone to add some extra oxygen. Cheers, Neale.>

Vitamin deficiency, shrimp as food, FW stingray fdg.    1/8/11
Hi crew,
I haven't had any issues for awhile, and I still really don't. But, I have a concern.
In one of our e-mails you had mentioned something about some sort of vitamin deficiency syndrome that results from feeding market (cocktail) shrimp.
<Mmm, likely Thiaminase issue/s. Read here re:
and the linked FAQs file above>
At the time, I had a silver Arowana that I was feeding them to. I no longer have the Aro, but I still have my Retic ray, who started eating the shrimp about 2 months ago. I'd been feeding him live blackworms because those were all he'd eat.
<A poor choice as a steady diet>
About once a month I'd put some shrimp in and he'd either ignore them, or recoil as if they were hot coals. I couldn't bring myself to attempt the starvation method to get him to eat the shrimp. Imagine my delight and surprise when I saw him start to eat them. Now he seems to really enjoy them, he sucks them up like a vacuum cleaner.
Are there any dangers associated with feeding shrimp?
If so, can you tell me what they are?
<I can>
What are the symptoms I should be looking for?
<Goiter, colour-blanching, bloating... Do read here:
and why not? The linked files above>
Thank you
<Please learn to/use the indices and search tool ahead of writing us on WWM. Bob Fenner>

Question about motors... FW Ray fdg. f'  -- 8/3/10
Hello Again!
I have a question that I am sure its nothing to serious. My going to be 2 year old motoro today didn't want to eat its first meal of the day. Tanks parameters are perfect(ph 7, Ammonia 0, NO2 0, NO3 20). He ate great last
night. I feed him 5 ghost shrimp and 7 frozen krill (which I defrost of course) and every other day night crawlers . Today I had to give him his food at noon which I normally do not do and it was small end pieces from the last of the frozen krill not the big amounts that I normally give him.
So I was wondering if I should be worried at all he is still moving around the tank like normal and the other fish are perfectly fine. Hope you can help!
<If he's acting normal, and there's no sign of physical damage or unusual posture -- e.g., fin curling -- then I wouldn't worry about it. Don't feed him for the next couple of days, and then see what happens. There's no
point dumping food in the tank if he isn't eating it, as all that will do is mess up water quality. Wait, test for ammonia and/or nitrite, and after a day or two, offer a small meal. Cheers, Neale.>
Re: Question about motors

Ok thanks. No he has no curling. I also did a water change to be on the safe side. Was wondering could I be feeding him to much?
<Possibly, but you'd expect to see water quality issues if this was the case.>
Don't know if they get upset stomachs.
<Certainly possible, but unlikely to cause long-term problems.>
Thanks again
<Cheers, Neale.>

motoro rays... Fdg., nutr. dis.   7/13/10
Greetings Crew,
I have two Male Motoro rays. They are about 10' disks now. Both have lived in a 1200 gal tank since they were 4" disk. They have a complete Life support system, reservoir, sand filter, chemical filter ,bio filter, R.O., UV sterilizer, chiller the works! I Back wash the system 2-3 times a week.
They live with discus and an Arowana and a few Blood Parrots they are in an aquarium we custom built in a local Casino. Within the last week they have slowly lost their appetites. They seem to have lost their desire to swim.
One has been bumping into walls and is now showing a lot of trauma to his disk. He swims upside down and has been puffing from the top. All my water tests are perfect.! They eat krill, bloodworms and any small schooling fish they can catch. I feel the bloods are taking advantage of them. Though the owner doesn't want to let them go! Ughh! To my question...I retrieved the Rays last night and isolated them in their own tank. I don't know what to treat them with. They are swimming about a little more today but the white (picking) areas look bad. And still not eating. Any and all suggestions are much requested.
Thank you
<Hello Ginger. The reasons why Stingrays refuse food are varied. As you correctly surmise, environment is the commonest issue. So yes, checking water quality, water chemistry, and water temperature are all important.
Consider any possible toxins: paint fumes, insecticides, etc. Make sure no-one has been doing anything silly to these Stingrays like feeding them human food "treats". Next up, the use of feeder fish. This cannot be
stressed too strongly. If you have predatory fish and you want them to die, feed them feeder fish. Never, EVER use store-bought feeders.
Goldfish and Minnows are the worst because they not only contain parasites but they also contain large amounts of thiaminase and fat, and used regularly will cause [a] vitamin B deficiency and [b] damage to the internal organs. Thiaminase is common in some types of seafood and fish, notably prawns, shrimps and mussels. Use thiaminase-rich foods no more than once or twice a week, and all the rest of the meals must be thiaminase-free foods. Until quite recently most aquarists had never heard of thiaminase, but it is now reasonably clear that this is a major source of ill-health and premature mortality.
If you've been using feeders or not taking care of the thiaminase issue, the damage may be done. A vet trained in handling cartilaginous fish may be able to offer some help, but otherwise there's little you can do. Next up, there's monotony. Stingrays need a varied die, and surprisingly, it needs to include some green foods for fibre. Cucumber, cooked peas and lettuce leaves are nibbled on by hungry Stingrays, and whether they're a major source of nutrients isn't clear, but their value as fibre does seem helpful. Zoos often create mixes with things liked cooked brown rice and carrots! If they won't take greens, then live earthworms are nearly as good, having guts filled with decaying leaves. Finally, there's harassment. Stingrays generally mix poorly with other fish, and suckermouth catfish in particular can harass them. As for their injuries, if these are nothing worse than scratches, these should heal fine assuming water quality is good. There are no completely reliable medications for treating Stingrays, which is why avoidance of sickness is so important. Potamotrygon spp. tolerate salt quite well, at least for periods of a few weeks, so in some instances slightly saline water may be helpful for external parasites, but generally that isn't necessary. If the Stingray can recover, it will do under its own steam. Cheers, Neale.> 
Re: motoro rays [RMF, any ideas on medications?] <<Furan cpd.s RMF>>  7/13/10
Thank you, unfortunately I lost one of them earlier today after writing to you. The other fellow is still struggling with himself. I have offered bloodworms twice to no avail. Is there no treatment to help the healing I could add to his tank?
<No. As stated, a vet who treats sharks and rays may be able to help, but adding "potions" as you'd do with regular fish won't have any positive effects at all. An antibiotic might be used safely, but you'll need to check with your vet or the manufacturer first.>
I have him now isolated in a 500 gallon holding tank. With a soft sandy bottom. The wounds are pretty much all white and some dark patchy areas on his upper side. Thank you for your time with me.
<As stated, if you have ever used feeder fish, you've basically thrown all your chances out of the window. Feeder fish are hands-down the single best way to kill predatory fish short of hitting them over the head with a priest. If you've offered thiaminase-rich foods too often, again, the damage is already done. It really comes down to this: if water quality is excellent, and the internal organs haven't been damaged by thiaminase or parasitised by the use of feeder fish, sick Stingrays can get better under their own steam. But if the damage is done, there's really nothing left but praying to the Fish Gods. Cheers, Neale.>

How to sex discus, & overfeeding FW Ray    7/5/10
Hi crew,
I have a couple of questions:
1) Can you tell me how to tell the difference between male/female discus?
<You can't. Of course, the genital papillae will be different, but by the time the female exposes her papilla the fish will be within hours of spawning anyway, so you'll likely know which fish are paired.>
2) I understand the concept of not wanting uneaten food remaining in the aquarium and rotting and fouling the water. But when I feed Blackworms, is it still a concern if there are any left?
My ray is always foraging, as are my discus. In fact, it seems that they can't seem to get enough. Will they stop eating at some point?
<Not really. If you're providing protein-rich, but fibre-poor foods, you're essentially asking whether a child will stop eating candy at some point -- yes, but not before that child makes itself sick.>
As their bellies swell, I figure that they've had enough. Is there a formula to follow?
<Experience; common sense. The aim is to provide enough to keep a normal body profile, but not so much they are swollen, or so little that their bellies have a concave profile. Under-fed rays lose condition quickly, while nitrate-rich water from overfeeding quickly stresses them. This is why you need a big aquarium and massive water changes to keep Stingrays healthy. Several small meals per day is better than one big one, and skipping a day doesn't do any harm.>
Also, is there a concern that overfeeding will cause more poop therefore fouling the water that way?
<Faeces are largely irrelevant, since they contain mostly material that doesn't decay into ammonia quickly/at all. The toxic ammonia comes from protein metabolism within the fish, and that's invisible to you. Uneaten food of course rots, and in doing so releases ammonia via saprotrophic bacteria.>
I have my tank on a "drip" water change, and this morning my Nitrates are less than 20ppm, judging by the color of the test strip, I'd say maybe 10ppm.
<20 mg/l nitrate is high by Stingray standards; you're aiming for near-zero levels, and preferably no higher than 10 mg/l. Anything above 40 mg/l quickly becomes toxic.>
As always your help and direction are greatly appreciated!
Thank you
<Happy to help. Cheers, Neale.>

Blue whale catfish... hlth., sel., FW ray fdg.... dwarf Orcinus...?   3/14/10
My husband and I bought two blue whale catfish,
<Interesting fish. Cetopsis coecutiens, one of a group of Amazonian catfishes known as the Cetopsidae. Rarely kept by aquarists because of their strange appearance, lethargy and strictly nocturnal habits. But apparently not difficult to maintain under aquarium conditions.>
which we have had for a little over two weeks. Yesterday we changed the water and today we noticed some white spots on their body, from what I read on your site, it could be ich.
<Very likely. All catfish lack scales, and the Cetopsidae also lack the heavy scutes (hardened skin) typical of things like Corydoras and Plecs. So they're very vulnerable to Ick and other external parasites. Treat using the heat/salt method rather than copper.>
We also have a fresh water stingray,
<I hope you won't be keeping these catfish with the Stingray! The Cetopsidae are "flesh biters", ranging from simply biting chunks out of bigger fish in the case of Cetopsis coecutiens through to swimming inside their gill chambers and feeding on blood, as in the case of the infamous Candiru. Without exception, Cetopsis are either kept singly (they're not happy that way) or in groups of their own kind (much better). But never, ever with other fish, except possibly larger, armoured catfish like big Doradidae. Make sure you feed these catfish a healthy diet, i.e., not goldfish or minnows. Earthworms are a favourite food, and you can augment these with fresh and wet-frozen foods of all sorts: tilapia fillet, squid, mussels, prawns, etc. The usual warning about minimising foods that contain thiaminase apply here, so while mussels and prawns are good in some ways, they shouldn't be used too often. Be sure to read Marco's excellent piece of thiaminase and aquarium fish for more on this topic.
Settled specimens may take carnivore pellets.>
and I want to make sure that I know what to feed him, he is about an inch in diameter.
<Feeding what, the Stingray? At an inch in diameter Stingrays are VERY easy to kill, and I'm surprised you were sold one this small. It's very unusual for (good) retailers to sell them that small. In any case, at that size they mostly feed on live insect larvae including bloodworms and mosquito larvae; wet-frozen may be take as well, but I'd start off with live food until the little chap has put on some weight.>
Also, this may sound strange, but is there such thing as freshwater or saltwater mini killer whales?
<Yes and no. Obviously no, there are no "mini" killer whales as such. But there are some small, pack-hunting fish. Of the species in the trade, Exodon paradoxus is the one most often kept by aquarists. If kept in large groups (like 20!) the pack works properly and they're great fun to watch when you throw a bit of fish fillet or seafood into the tank.
Unfortunately, too many people try to keep this species in smaller groups, and even in groups of 10 they have a tendency to turn on one another, and you end up with just one specimen.>
<Cheers, Neale.>
Re: re: Blue whale catfish   3/14/10
Where I bought them from, they were in the same tank together and the catfish don't seem to be bothering the little stingray.
<So far. But what these catfish do in the wild, apparently, is swim about at night and bite chunks from anything too big to be swallowed whole. See how they lack long whiskers? That's so there's nothing to get in the way of that big mouth when it's pressed against its target. These aren't "scavengers" that use their whiskers to find worms and such in the mud!
Your species is a large (25 cm/10 inch) predator that cannot be kept in multi-species tanks.>
I also looked up the "mini killer whale", and I didn't find much on them.
Do they have blow holes and or use them?
<I have no idea what you're asking here. There are no mini killer whales.
You're talking about the big black-and-white dolphins, right? As for freshwater fish species, there are things called Baby Whales, and this is a nickname used in the trade for small, schooling Mormyrids, in particular Pollimyrus isidori. Mormyrids are difficult fish to keep, and I'd strongly recommend you read up on their very specific needs before buying any. They are difficult to mix with other fish, and because they are sociable electric fish, you have to keep a certain number or else their communication goes haywire and they bully each other. Six is a good number
to start with.>
Or do the catfish? We were waiting for a mini killer whale, that the pet store said that they could get and have had one before, and she also said that they used there blow holes.
<She's talking nonsense. There are no cetaceans sold as pets via aquarium shops. Whatever she's talking about, it's not a "killer whale". I haven't a clue what she actually means. If you can get a Latin name, then I can help.
But otherwise...>
Any way, when the catfish came in, she told us that the whales were in, and she said that they use their blow holes, I know I asked above, but is that true?
<No fish has a blowhole. A blowhole is a nostril used to pass air to the lungs. Since fish don't have lungs and breather via their gills anyway, they don't need a blowhole.>
I feel like this pet store has done nothing but lie us.
<"Lie" is a strong word, but ignorance is VERY common in some parts of the hobby. The solution is simple. Find out about the fish first, then get some information from a trustworthy aquarium book. Failing that, e-mail us here,
since we write books and magazine articles, and we're about as reliable a source of information as you're going to get. If you don't have the Latin name for the fish, and the common name the store clerk offers doesn't match
anything you can find in a book, then take a photo and send that. But whatever you do, read before you buy.>
I also bought what I was told to be a freshwater dragon fish.
<A brackish water goby, Gobioides broussonnetii. Actually very easy to keep in a brackish water system. But yes, its lifespan in freshwater is minimal, and it does need a good, varied diet based on stuff other than mere flake.>
Unfortunately it died three or four days later. I believe that this pet store doesn't care about their animals, but more about the money. I can't believe that any person couldn't give a care about the animals that they are selling.
<Caveat emptor, I'm afraid. If a store really does go out of its way to be disingenuous, you might want to ask to speak to the manager and explain your concerns. If that doesn't help, write to your city or county retail licensing office. Pet shops are regulated to some degree, and they have to provide a certain degree of care to their animals. If they're failing in that regard, then the city or county will inspect them, talk with them about how to improve, and if necessary remove their license.>
<Cheers, Neale.>

Re: Rays, comp., fdg.   12/28/09
My smaller ray is 4 and a half inch diameter and my bigger one is 6 inch diameter. I know they will get 14 inches because they are p. Reticulate.
Will 7-9 inch long lima shovelnoses be okay with them.
<Yes; though Sorubim lima can, will reach at least 30 cm/12 inches and frequently 45 cm/18 inches.>
My rays are now growing rapidly now on uncooked shrimp rather then bloodworms.
<Do not use shrimp more than a couple of times per week; shrimp, particularly that which has been frozen (even if sold defrosted) contains a lot of thiaminase but little or no vitamin B1. The end result is while the
calories and protein are in these foods, over time you run a serious risk of vitamin deficiency. Do read here:
Augment their diet with thiaminase-lacking foods, e.g., earthworms, tilapia fillet, cockles, etc.>
Thanks for all the help!
<Cheers, Neale.>
Re: Rays
if not lima shovelnose, what is a few more catfish that will be fine. My LFS barely ever has them in.
<To be honest, I'd take your time and have your retailer order them in.
Sorubim lima really are THAT GOOD as catfish go. Otherwise, some possibilities include Pimelodus ornatus (a rather smaller Pimelodid catfish) and Leiarius marmoratus (a much bigger Pimelodid). Almost all of the larger Loricariidae can work, including things like Panaque nigrolineatus, Acanthicus adonis and Pseudoacanthicus sp. L025, but as ever with the Loricariids, these are territorial and grossly polluting animals so should be mixed with Stingrays only after due consideration for their needs. Catfish like these can damage Stingrays when quarrelling over space, and the resulting wounds can be fatal. So ensure the "footprint" of the tank is big enough for all concerned, and that there are hollow, tube-shaped caves into which the Loricariidae can withdraw and feel secure
away from the Rays. Cheers, Neale.>
Re: Rays
Ok thanks, ill stick with lima shovelnose.
<Cool. Enjoy your fish. Cheers, Neale.>

Question about Motoros... fdg... hlth.... env.  6/19/09
I have a 8 month old stingray. My question is simple. He ate well this am i feed him ghost shrimp. Tried to change him to live red wigglers this weekend and he ate about 3. But not he seems disinterested in food. This evening i gave him his 10 shrimp and he didn't even bother to catch them. I check the water and everything was normal ph-6.0 am-0 n-0. So i know its not the water. I know they go on hunger strikes but i was wondering should i be worried?. I looked at your web site to see if other people have the same problem but it didn't really answer my question. He does this i notice only when i try to change his food. Is he just spoiled? Or is he sick?.
Don't know what to think hope you guys can help me out a bit. THANKS!!!
<Maria, you absolutely *should not* rule out water chemistry or water quality issues! These are BY FAR the most common reasons Stingrays stop eating or otherwise behave abnormally. Because you have a very low pH, 6.0, your biological filter will be working at a very low efficiency, so nitrite and ammonia spikes through the day are possible. In case you're wondering, biological filter bacteria prefer pH to be in the range 7.5 to 8.5, and the lower the pH goes below that range, the less they work, and below pH 6.0 they don't usually work at all. A very low pH also implies minimal carbonate hardness (what you measure with a KH rather than GH test kit) and that means that pH may well vary through the day, so again, take pH readings several times: before you turn the lights on in the morning, around midday, and sometime in the evening, at least. Ideally, you would be keeping a Stingray in water with a moderate amount of carbonate hardness
(4-5 degrees KH) and a pH around neutral (6.5-7.5). But as you hopefully know, making sudden changes to water chemistry will stress a Stingray, so if you do decide to alter water chemistry, you need to do so very carefully and in small steps. If for some reason your Stingray doesn't particularly want to eat the food you're offering him, then try starving him for a couple of days and see what happens. Besides earthworms and river shrimps, Stingrays should receive a variety of foods so that shortcomings on one are balanced by the others. Frozen seafood often works well, and things like squid and cockles are particularly nutritious and lack the thiaminase found in mussels and prawns. Small pieces of white fish are good, too, and you can buy frozen lancefish that can be used whole. This said, earthworms and shrimps are favourites, so be critical of environmental conditions and fix them, rather than missing this "early warning" and not realising something
was wrong until the Stingray got sick. Cheers, Neale.>

Re: Question about motors... Potamotrygonid sys.  6/25/09
Hello again.
Got your e-mail back. To clarify a few things i KNOW for a fact there is not spikes in either Am or N because i have tested thru out the day (every couple of hours) and are reading zero plus i have two filters on my tank.
<It's good you can be sure that water quality isn't an issue. Having two filters doesn't automatically mean you have perfect water quality though, so I'd dissociate those two ideas! But let's assume these two filters are adequate to the task, i.e., big canister filters that are maintained at least monthly so that there aren't issues with either turnover or nitrate levels rising between each time the filter is cleaned.>
He eats fine just is burred more the usual. Going to be up grading him to a bigger tank and want to make sure he is health before moving because of stress.
<There are multiple things you can think about. Firstly, is water circulation adequate? Hang-on-the-back filters for example have their inlets and outlets close together, so are less likely to provide good water
turnover than canister filters positioned with the inlet and outlet at different ends of the tank. If you're using hang-on-the-back filters with large fish, providing additional circulation via powerheads is probably
essential, especially given that Stingrays get their oxygen from a layer of water at the bottom of the tank, the layer that contains the least oxygen because it's furthest away from the air. Secondly, is diet sufficiently
varied? River shrimps are fine when used some of the time, but shrimps contain a lot of thiaminase, and this leads to severe nutritional imbalances in the long term (vitamin B1 deficiency) so you need to balance
them out with food items that don't contain thiaminase, such as earthworms and cockles. Here's an article that summarises this very important but often neglected topic:
Thirdly, consider "psychological" effects. Stingrays will become stressed if there isn't sufficient swimming room, if house with aggressive tankmates, and perhaps if housed in a room with a lot of noise. Review, and
act accordingly. Generally speaking fish don't go off their food for no reason, and assuming that they're simply not bored with whatever is being offered, there's usually some environmental or health problem that needs to be fixed. Cheers, Neale.>  

Re: Question about motors
Thanks so much!..i am trying to get him a more variety of diet but every time i do he only eats its the new diet for about a day or so then doesn't want to eat.
<Are they still alive/wriggling when offered?>
Anything you suggest on how to get him to eat a new diet. I did buy red wigglers for him and he like i said ate some of a day and then didn't want them. So i have been trying to switch up his food but un successful.
<There are numerous books on Stingrays; I'd suggest borrowing or buying one of them so that you have a detailed account of feeding this difficult and expensive fish. But in brief, pieces of squid, mussel, white fish and even small amounts of oily fish such as salmon have all been used successfully.
Live "feeder" fish are not recommended unless home-bred livebearers or killifish, which are "safe" in terms of fat content, thiaminase, and parasite risk.>
<Cheers, Neale.>

Re: Question about motors 6/25/09
Yes they are alive and moving he will attack them but then realize eww i don't want this.
<Odd, usually they love earthworms. Maybe try different types/sizes of worms?>
i do have a book on fw stingray got them before buying the ray to educate myself.
<Very good. Cheers, Neale.>

Re: Question about motors 6/25/09
I will try.
Thanks a bunch!!
<Most welcome. Cheers, Neale.>

Hopefully a quick question 05/27/09
Just was wondering my motoro that I have for the past seven months is doing great!. but this past weekend since we had the holiday and all my pet store was close where I get his food so he didn't have any food for almost 3 days. (feed him today and ate great) but I notice he was a little skinny.
Can just three days caused such a show of skinniness?
<Potentially, but not likely; it takes a good couple of weeks before fish really have to dig into their fat reserves, hence the standard advice that it's safe to leave fish without food over holidays than to risk have someone overfeed them during your absence.>
Of course I tested the water just to make sure things are ok and it was good (just a tiny spike in ammonia )
<No such thing as a "tiny spike" of ammonia with Stingrays, anymore than a person can be "a little bit pregnant".>
but he always cause it to go up because he plays in the sand so he brings it up sometimes. Stressing out because of the ammonia spiking up here and there and then he lost weight. just wanted to know if I should be worried?. How long will it take for him to put weight back on?(feeding 20 shrimp a day) Also as an added note. He didn't eat his shrimp today which is not like him!
<Would review water quality and maintenance procedures; Stingray health -- including appetite -- is closely correlated to environmental parameters, and they invariably feed readily on live shrimp and earthworms when properly maintained. So rather than worrying about the food, worry about the water. Do also vary the diet: shrimp is rich in thiaminase, and this means that while your fish can get the calories it needs, the thiaminase can lead to a Vitamin B1 deficiency. By all means use shrimp for one or two meals out of seven, but the rest should be foods lacking thiaminase, such as earthworms. See here:
This is a critical issue that aquarists are only slowly comprehending.
Cheers, Neale.>

Possible Motoro Parasite/Feeding Frustrations (RMF, second opinion please) 3/10/09 Hello, <Hello Kyle,> Before I ask my question I think it's important to note that my 7 inch Motoro was purchased and acclimated 3 days ago, so he is still undergoing the typical acclimation stress (and the underside of his disk is reddish). Now that he has become more acclimated and begin scrounging for food, I noticed a small brown spot on the underside of his disk in the shape of a butterfly, with a little raised light-colored bump in the center of the spot. I have attached the best picture I was able to get of the spot (my ray swims fast on the glass), but I was wondering if this could be a parasite that hitched a ride on my ray; and if so, where can I find instruction to remove it as safely and stress-free as possible? <It isn't clear to me what this is, and I'm asking Bob for advice here.> <<Isn't clear to me either, but at largest amplification, cleaning up... and the position of this mark... it appears to be more of a "bruise" to me than anything else. Not parasitic. RMF>> In case it helps, my tank is registering nitrates at 5 PPM, with everything else at 0. I have a fine sand substrate and filtration to turn 10 times the volume of the tank. In addition, I was wondering about feeding. I have read and heard of stingrays on "feeding strikes" or "not accepting food" but mine seems to be very fickle about his food, neither accepting nor rejecting it in any predictable way. He's nearly always blowing the sand around looking for food, but if he does pick up a worm or small piece of raw shrimp, he will sometimes spit it out of his mouth even if he's accepted it from me greedily before... only then to further swim around the tank looking for something else to eat. One example is just an hour ago, I put half a live nightcrawler in there, and he sucked it out of my hand hungrily, then spat it out. For the next half hour he would gnaw at it, spit it out and then swim around the tank, eventually eating it. So far, I have tried bloodworms, red wigglers, nightcrawlers, and ground raw shrimp; all which have been accepted and rejected in an unpredictable fashion. Thank you for your time and advice, I look forward to hearing back from you. Kyle <While these fish are finicky, one key thing about their appetite is stress. So your Stingray may simply be settling in and not ready to feed consistently. But it could equally easy be an issue with water quality or water chemistry stability, so think about these factors too. Review tankmates, and see if there's anything that might be stressing the Stingray. Take care not to overfeed; when we bring home a new fish, it's tempting to keep feeding the new fish to check it's healthy and happy. Cheers, Neale.><<Totally in agreement. RMF>>

Re: More: re: Possible Motoro Parasite/Feeding Frustrations (RMF, second opinion please) 3/12/2009
Hi, guys- thank you for your help and quick responses. I tried to see what might be stressing him, but the water seems stable,
<"Seems"? You don't get this latitude with stingrays; the water MUST be stable. Keeping them in huge tanks helps, as does performing very regular (ideally, daily) water changes so that background acidification doesn't get
a chance to occur. The carbonate hardness should be reasonably high; while soft water fish in the wild, pH variation is much more harmful than moderately hard water.>
he has no tank buddies, and the temp is kept at 80 degrees.
<Too warm. The usual 25 C/77 F is ample for these and indeed most Amazon Basin fish (with a few exceptions, like fish from the Xingu River which do like things a bit warmer). The warmer the water, the more active a Ray will become, but the cost of higher metabolism is increased demand for oxygen and a heavier workload on the filter. Unless you're breeding fish, it's usually best to keep them at the cooler end of their preference range. Not cold, by any means, but verify their preferred temperature range from Fishbase or similar, and work from there.>
And I have decided to call that brown spot a "beauty mark" and will continue to do so until the moment (if and when) it appears to be a trouble spot.
I have noticed since my e-mail before that there is a small amount of regularity in his feeding. He seems to have no trouble accepting one nightcrawler in the morning and evening, but anything after that he will not eat. His belly also appears to be getting less and less red each day (although this may partly be wishful thinking more so than objective observation)... so I am taking that as a sign that he's getting better acclimated.
It's still a little weird to me that he is spending a lot of time blowing sand around looking for food, but won't eat much, and then spends a lot of time swimming in the same pattern around the glass.
<What kind of sand are you using? Anything likely to irritate? Many aquarium sands are too sharp for benthic fish. If in doubt, plain vanilla "smooth" silica sand is fine.>
I actually had to put a book on the corner of my tank, because it appears as though he keeps trying to jump out that corner (I wont worry about a tank cover until I see him trying to jump out anywhere else).
<Normal behaviour if they're stressed. Again, this may stop if the fish settles in, but if it persists, then review conditions and act accordingly.
The usual problems with Stingrays are insufficient water volume,
insufficient filtration (water turnover), and unsteady water chemistry.>
Is it possible, since the tank at the store was decently decorated, that adding some small decorations would help him with his level of comfort, or are rays not as concerned with decor as some other fish?
<Wild fish hide by digging into the sand. Floating plants will certainly be welcomed for the shade they provide, but bogwood, rocks, etc are redundant and indeed undesirable if they trap dirt.>
Well, it seems this 'thank you' has turned into a "holiday mailer" so I will cut it off here. Thanks again for all your help,
<Cheers, Neale.><<Excellent resp. Neale... content, format wise... Have nothing further to add. BobF>>

Re: More: re: Possible Motoro Parasite/Feeding Frustrations (RMF, second opinion please) 3/12/2009
With regard to the substrate, it is a very fine sand. It may be that the granules, although small, are sharp if the sand is an issue.
<Feel the sand; smooth sand feels velvety, sharp sand feels otherwise.>
If upon further investigation of his habits, I determine that the substrate
is causing him irritation, would adding a small layer of a different, smoother sand work?
<Replace all the old sand with smooth sand. No point being cheap here; for the sake of a few dollars' worth of sand, you could end up with an infected Stingray. Dump the old sand in the garden. Mixed with soil, it helps improve drainage. So no waste.>
I am trying to avoid ripping out the bio-colonies in the sand by replacing the substrate altogether.
<No useful bacteria in the sand.>
Perhaps replacing the substrate over time, bit by bit? What would work best for that?
<Replace all.>
Now that I read what I wrote, I realized "seems" doesn't fit what I am observing with the water. That was my way of saying I am checking it daily, levels are fine, so unless there are fluctuations in the water source here in ways I can't measure, then water quality isn't the issue. So, in this case, seems=if something's wrong, it's going to catch me off guard.
<Right, I see.>
Sorry to be such a bother with all these questions and trouble. This is (quite obviously) my first ray, so I am erring on the side of cautiousness, which may not be an err in ray-keeping at all.
<Very wise indeed. Do invest in one of the several books on the topic. Some are inexpensive (like the Barron's one) and will save much money in the long term.>
<Cheers, Neale.>

Re: More: re: Possible Motoro Parasite/Feeding Frustrations (RMF, second opinion please)   3/15/09
I thank you again for your assistance. I don't know what the problem could be anymore, because the substrate feels soft and smooth to me, not scratchy like some sands I have used.
<Well, that's good.>
Water quality is fine and I have been changing at least 10 percent of the water every day.
<Define "fine". The thing with Stingrays is that 99 times out of 100, problems are down to water quality and/or chemistry issues. Obviously you need zero levels of ammonia and nitrite, but nitrate also needs to be very low, realistically as close to zero as is practical. The water chemistry should be stable; ideally soft and slightly acidic, but regardless of the hardness level, the pH should be rock steady.>
He simply is refusing to eat anymore.
<Was he feeding at the aquarium shop? What were they feeding him? For all the usual reasons, I'd never recommend buying a specimen that was fed feeder fish, particularly goldfish. But if it was consuming earthworms and other safe foods, it should be in good shape. Assuming he's eating something, and has hitherto taken a meal every couple of days, he can be "starved" for a week or more without problems. But the flip side is this:
Stingrays tend to be greedy feeders for things like earthworms and live river shrimp when happy, but refuse to feed point blank when stressed in some way.>
There seems to be a connection between me coming into the room or near the tank to do maintenance and him going to hide in the substrate.
<Some degree of nervousness is common initially after purchase, but fish generally settle down within a few days to a week. Do review the general environment though: loud televisions, slamming doors, busy corridors can all make fish much more nervous than otherwise.>
I am honestly getting a little frustrated with this guy; I really only try to feed him morning and evening. Maybe I just need clarification on what people mean when they say "feeding strike." Obviously, there's an element of non-eating, but if he's on such a "strike" then why does he spend the whole day searching for food?
<To some degree you must dissociate foraging behaviour with actual feeding; fish will instinctively forage for food all through their day (or night) activity cycle. They don't need to be eating constantly though, and simply because they're foraging doesn't mean they need to be fed.>
Most times, he finds what I give him and greedily begins to suck it down but then spits it out or leaves it, and then goes to hide.
<Maybe he doesn't like it? What are you offering?>
I'm afraid I am going to lose this guy, and it just feels wrong because I have been doing everything that I have been told either by people or by my very deep research (I did get the Barron's book before I bought him).
<My gut feeling here is this: [1] Review environmental/water conditions; [2] Double check them! [3] Turn the lights out for the next few days. [4] Don't feed him for at least 3 days. [5] Get some nice, fat, juicy
earthworms and offer one of them late in the evening on the fourth day.>
I am sorry there wasn't much of a question in this e-mail. I guess I figured I may have said something about his behavior that may show something we haven't noticed before.
<Cheers, Neale.><<I do agree with your probable prognoses... advice Neale... If none of these can be found to be at fault, when-corrected, restore this fish to feeding, I would return it to the store. BobF>>

Re: More: re: Possible Motoro Parasite/Feeding Frustrations (RMF, second opinion please) 3/15/09
Hm... thank you for the distinction between searching and hungriness. That has helped me a little. When I bought this one, I was actually in the LFS looking at another stingray that they tried to feed an earthworm and he didn't go for it, but this guy came speeding up to it and started to eat it down; he looked healthy and obviously hungry so I got him instead.
<An excellent way to choose Stingrays.>
He did have a little trouble eating the whole thing because he's a smaller ray still, but he did (and still does) get the whole nightcrawler down eventually. I have also tried breaking the worms in half or 3 parts but he loses interest or only eats the front-worm part. Thank the Lord I care for an African clawed frog who will eat what my ray rejects. Other foods I used are glass shrimp and raw supermarket shrimp, and red wigglers.
<Do try something very small, like bloodworms. Shrimp are fine up to a point, but because they contain a lot of thiaminase, it is sensible to use them in small amounts, no more than 25% the weekly food input. Earthworms are very nutritious, in part because they are 'gut loaded' with decaying plant matter and soil. While that sounds icky, it does mean they provide lots of useful vitamins, minerals and fibre.>
I will try not feeding for a couple days. My only worry is that he's already looking very malnourished from his rejection of food (hip bones showing, dent in forehead, etc). I will do that if he can last the couple days without food even like this.
<Well, if he's not eating, he's not eating. So whether you put food in the water or not, it hardly matters. I'd certainly stop offering food he shows no interest in. A day or two starving should make little difference, though I agree, a "skinny" Stingray is at risk.>
Water quality (ammonia/nitrite/nitrate) is still stable, nitrate at 3 PPM and I am going to change 20% of the water again today.
<The nitrate is fine; the nitrite is zero though?>
I honestly do not know about PH... maybe I made an unsafe assumption that using the same water source each time gives the same PH.
<Ah, yes, this matters. A lot of people in the US seem to have water that has been treated in various ways by the water company, presumably to improve its potability. But the chemicals used, such as flocculants, cause the pH to change dramatically within 24 hours of being drawn from the tap.
Try testing the pH of some tap water now, and then leaving the same water for 24 hours and seeing what the pH is then. You might be surprised. Also, do of course remember the basics: don't use water from a domestic water softener, do use dechlorinator, and do use a dechlorinator that treats ammonia and/or chloramine if either are issues with your local water supply. You might also want to check for copper in your tap water supply.
If your pipes are made from copper, it is possible for tap water to become contaminated. Copper is highly toxic to Stingrays, and such water supply will need to be treated with a water conditioner than neutralised copper.><<And copper ion presence would definitely send them off feed. RMF>>
<Cheers, Neale.>

A worm question (Horsehair worms; stingrays)   10/17/08 Hello, <Hi,> was just wanted to know I notice some of my ghost shrimp have worms in there intestines are to believe they are Gordian Worm, a.k.a. Horsehair Worms...one died bc the worm killed it but I never notice them b4 on my shrimp I feed these shrimp to my Motoro stingray which I have had for about a week I know they are prone to roundworms and tapeworms but I was wondering if I did feed some shrimp that had these in them can they kill my ray I called the pet store where I got my ray and they never really heard of these worms really and are not sure if they will harm the ray they feed there ghost shrimp to there rays and had no prob but they never looked at there shrimp to see if they had worms so they could be feeding ones that do so I don't know what I should do I don't want my ray to die and I don't know if I should get new shrimp the other ones seem to not have these worms in them..should I continue to feed them to my ray or go and get new ones?????? <Sheesh... not even a period or comma. Do please review our very modest "fee" before writing: we expect e-mails to be spell checked and written with proper grammar. Not much to ask, and the point is that we depend on properly formatted messages so that we can share them with other site visitors. The better Google can index our pages, the more people will view our pages, and the more revenue our advertising generates to pay for bandwidth. It's a simple deal really.> HELP!!! PLEASE KINDA SCARED FOR MY RAY I LOVE HIM!!! <Horsehair worms are not likely to cause your Ray any harm. Most parasites are species-specific, and while they may be harmful to the shrimp, they are unlikely to adapt to the particular anatomy of your Stingray. If you're really that bothered, don't use the shrimps. Earthworms are a very safe food if collected from an area that is "organic", i.e., not sprayed with chemicals. Most rays love earthworms. There's no reason to use live food with most Stingrays anyway, and a varied diet of mussels, prawns and squid is easily provided using foods sold for humans.> thanks Maria <Cheers, Neale.>

FW Ray Feeding 03/19/2008 A quick question on my hystrix rays. They seem to want to eat constantly. <Yes. A good sign> They are on frozen foods, I think there's virtually nothing they wouldn't eat but I can't seem to figure out just exactly how much is too much or too little? <Better to keep a bit hungry> They are both young. The female is about 6 inches diameter and the male about 4 inches. She's the bigger piggy of the two but both are all about the food. This is my first time emailing you and your website is fantastic. I work in a pet store and recommend your site to my customers frequently. <Have seen in some stores that they have terminals for all to peruse the Net... Neat idea!> I hope this isn't listed in the FAQ section somewhere but for love nor money I could not find it. <Ahh, this and life-times more info. to be added... as long as your Potamotrygonids aren't obviously concave in the tummy region, they're fine... Better for all to have them grow slowly, not pollute their tank. Cheers, Bob Fenner>

Stingray not feeding, FW    11/16/07 hi i have a young freshwater stingray it has not fed since i got it. i have had it for about 4 weeks. i have poot it in a new tank on its own. <Sorry, what's the question? There are many reasons why Stingrays won't feed, and almost all of them come down to improper care. So the problem is much more likely with you and not the fish, and unless you fix that problem, it'll die. Stingrays are exceedingly difficult fish that should only ever be kept by aquarists with many years experience. They need big tanks in particular with a wide surface area, at least 75 cm by 200 cm, and filtration needs to be top-notch, of the order of 10 times the volume of the tank per hour. Water changes need to be not less than 50% per week, and really two or three times that. Water chemistry isn't critical, but water chemistry stability is, so that needs to be factored in, and chemical buffering used if appropriate. There are no "small" species, and the appealing little juveniles widely sold are even more delicate than their parents. I'd suggest that around nine out of every ten stingrays sold dies within the first six months. Almost no-one who tries keeping them succeeds, UNLESS they have lots of experience and done plenty of reading. And even then, it all comes down to having a big tank with perfect water quality. When healthy, stingrays will eat pretty much anything: river shrimp, earthworms, chunky seafood, silversides, etc. Cheers, Neale.>

Re: stingray not feeding -- 11/17/07 thank you for your time, ill let you know if I get it feeding <You're welcome. Good luck! Neale>

FW Ray fdg.  - 7/23/07 Hi Robert I am not sure if you are the guy to ask this question but her i goes. I have a Motoro ray he is about 6" was doing real well. My water quality is perfect <?> and so is the temperature. <Is this a guessing game? How about some clues if so?> His tank mates are a Pleco and a couple surviving tetras (food) I made the mistake of just feeding him earth worms fro a couple months ( I know bad) Gave him kidney or liver failure. He lost tons of wait and is real skinny. I am trying to bring him back to his heath again. I have been feeding him bud worms for the last few days he seems to be eating them but there not too filling I don't think. He does not want to eat any frozen krill or shrimp. I am even trying to feed him a small live 3/4" crayfish. But he does not seem too keen on it or the ghost shrimp. Do you have any suggestions for me that might get him eating again. <Mmm... need to know the values you hint at above... likely lowering the pH, raising the temperature, offering live food... maybe like ghost shrimp... Possibly soaking in a vitamin/HUFA supplement...> Yes I learned my lesson f/w rays need variety for food. Thanks in advance Kevin B Me Kevin B. <Please read here: http://wetwebmedia.com/FWSubWebIndex/fwrayfdgfaqs.htm and the linked files above. Bob Fenner>

Stingray issue  7/22/07 Hi there, My question is about my fw stingray. I currently am housing 3 fw stingrays, 2 Motoros and one reticulata (teacup). Motoros are 12 in and 6 in and teacup is 6 inches . I have had them for about a year in a 265 gal with a large Pacu and 14 in silver Arowana. As of late the smaller Motoro has been swimming above where the air bubble wand and filter outtake meet. Its def out of character for her. I am using a Fluval fx5, an emperor BioWheel and Eheim canister for filtration. One of her eyes seems cloudy and closing. I lost the first ray I had a year ago and he showed some similar signs. Ammonia 0 nitrate 0 ph 6.0. Temp about 82. I feed rays jumbo night crawlers I get from bait shop and once in a while feeder goldfish but not to much. I added Pimafix. She also has a little red around her mouth. The swimming funny really has me thinking somethings up. She eats and has not lost any weight. Any helpful hints. I would really appreciate any help your site is the best. Oh and substrate is sand very easy on them. <Greetings. As you probably realize, freshwater stingrays are exceptionally difficult fish that are only suitable for very advanced, highly experienced fishkeepers. When it comes to disease, the problems are that [a] we don't really have a textbook list of stingray diseases yet and [b] many of the medications safe with bony fish are dangerous to cartilaginous fish. Now, as a general rule, when fish swim into the filter current it is usually because this is where the water quality is highest and the oxygen concentration highest. Likewise, when fish show red patches on this skin (signs of irritation) then again, water quality is something to think about. In your case, you need to be reviewing a variety of things. Ammonia and nitrite obviously (you say the former is 0, but how regularly do you test it? try testing over a week and at different times of the day, especially shortly after feeding). Nitrate needs to be as close to zero as possible, which you say is the case. But water chemistry is also important. Stingrays aren't that fussed about pH and hardness, but they are bothered by changes. So if you're manipulating your water supply to get the low pH and hardness levels you have, check to see you're being consistent. Another issue is air or water pollution: it's easy for things like paint vapours and tobacco smoke to end up in the aquarium, and these will irritate/poison the fish. Yet another issue is filter turnover. For a stingray, I'd recommend not less than 8x the volume of the tank in turnover per hour (i.e., marine quality filtration and twice that for regular small community fish like guppies and tetras). Given your aquarium is 265 gallons, that means you need filtration around 2120 gallons per hour, minimum. Your Fluval delivers about 600 gallons per hour, the Emperor 280 gallons per hour, and the Eheim I don't know how much because you don't say the model. But it needs to be *at least* 1240 gallons per hour to even make the baseline your stingrays need. Since even a really big Eheim like the Professional 3 is only producing a "mere" 450 US gallons per hour turnover, your tank is very likely (almost certainly) under-filtered. Some more general advice. Melafix and Pimafix are largely useless as treatments. While they sometimes work for some people under some conditions, they're too inconsistent to be relied on, and therefore of no value with expensive fishes like yours. Another problem is diet. Stingrays feed on a variety of animals in the wild including small fish, but never Cyprinidae. The nearest Cyprinidae are hundreds if not thousands of miles away from where they live. Why do I mention that? Because Cyprinidae -- things like goldfish and minnows -- have high quantities of Thiaminase that breaks down Vitamin B1 over time. They also contain a lot of fat. Fish that eat them in the wild, like pike, presumably are adapted to this, but most other predatory fish do not seem to be, and long term both these issues cause damage. Bob Fenner has written at length on the issue of feeder goldfish and marine predators like Lionfish. Since your stingray is, basically, a marine fish that happens to be living in freshwater because it got trapped on the wrong side of a newborn mountain range, your stingray likely will react the same way to a high fat, high thiaminase diet as any other marine predator (i.e., poorly). On top of this, feeder fish are the Number 1 best way to introduce parasites and bacteria into your nice clean stingray aquarium. To be honest, whoever advised you to feed cheap "parasite time bombs", sorry, feeder goldfish, to something as delicate and easy to kill as a stingray deserves to spend some quality time on the Naughty Spot. The ideal foods for stingrays are either terrestrial foods (like earthworms), marine foods (like mussels and prawns), or "clean" frozen foods (like bloodworms and lancefish). All these will be safe because they have no chance of introducing parasites or bacteria into the aquarium likely to harm a freshwater stingray. Over here in the UK, live estuarine river shrimp are widely used with success and these match very closely the preferred staple diet of freshwater stingrays in the wild: large crustaceans. As you realize, stingrays have teeth adapted not for catch fish but for crushing shells. Finally, the whole sand issue in aquaria for stingrays is debated endlessly. There's some good evidence that dirty sand can trap bacteria and cause infections. This has been observed on catfish barbels for years (erroneously put down by some people to "sharp" gravel wearing the barbels down). Catfish generally shrug off such infections and re-grow their barbels when conditions improve, catfish being, fundamentally, very hardy animals usually adapted to swamps and other horrid environments. Stingrays do not have this level of robustness. So double check the sand is spotlessly clean. You should be stirring it weekly and siphoning out any detritus. Many stingray keepers prefer to keep their rays in tanks without sand to side-step this issue. Finally, do check the fish aren't able to burn themselves. It is *extremely* common for stingrays to burn themselves against the heater. The heater should be either inside the filter or covered with a plastic mesh of some kind (called "guards" and these often come with the better heaters anyway). Hope this helps! Cheers, Neale.>

Motoro sting ray... RMF rant on the new trade, poor env., poisoning, lack of useful info.  - 02/15/07 Hello, I have a motoro stingray with a sand substrate. <Hopefully not silicate... but smooth...> I was using new Tetra Tec filters with internal heaters to protect the ray but the impellers kept failing. <What is happening with the "new" Tetra? And while we're at it... Aquarium Systems salts? Oceanic Tanks...?  What gives with the "consolidation" of the pet-trade anyhow? The big owners are doing a crap job of "managing"...>   I switched to Filstar Canistar filters <Am not a fan of...> and had a mild algae bloom.  I treated the tank with a small amount of "algae fix" <NO!!! Toxic...> which corrected the algae issue but now she refuses to eat. <Poisoned...>   It has only been three days and I have tried bloodworms, ghost shrimp, and krill all of which she used to love.  All levels are fine <... worthless> and she seems fine but I would like to know if there is anything I can do to get her back to eating regularly? <...> I do not think that the filter change is the problem because I changed the filter on another ray tank at the same time and that teacup ray is eating normally. I did a water change but she still refuses to eat. Bob Fenner had some great advise which helped in setting up for both my ray tanks and I hope that he or anyone else can help with this question. Please advise, Thanks, Joe <Please take the (re)read here: http://www.wetwebmedia.com/FWSubWebIndex/fwstingrays.htm and the linked files above. I would do a series of water changes to remove the algicide, make sure the water is warm, soft, acidic per this species requirements... and be patient at this point. BobF>

Hystrix Stingray Not Eating?   1/23/07 To Whom It May Concern, <Okay> I have had a Hystrix Stingray in a 250 gallon tank for approx. 9 months and she has now stopped eating?? <Mmm, you tell me... Potamotrygonids, in fact all cartilaginous fishes do periodically seem to go on feeding strikes... generally no problem> I checked the water quality (ammonia = 0, nitrates = 0)and have even performed two water changes (approx. 20%) over the last 4 days, but to no avail? <Was I there with you?> She was eating shrimp (4-5 per day), <Mmm... I wouldn't feed this much, and not daily> bloodworm cubes, earthworms, salmon, but is no longer accepting any of the above. The water temp is approx 80-82 degrees and the PH is 6.0-6.2. I am unsure what to do, but she has not eaten in approx. 5 days and is looking very thin and weak. <Do you administer vitamins? Iodine/ide?> In the past, she was very aggressive when eating and would accept food as often as I would put it into the tank. Is there some type of medication that I should add to the water? <The aforementioned supplements> Thanks in advance for your help. Regards, Steve <Please read here: http://wetwebmedia.com/marine/fishes/index.htm The second tray... Batoids Disease, Potamotrygonids Feeding... Bob Fenner>

Re: Hystrix Stingray Not Eating? Wasting WWM time   1/24/07 Thanks for the suggestions.  How long (theoretically) can she go without eating (considering she was very well fed prior to her fasting)? <Mmm, at this size... a couple of months likely> I just placed a bunch of ghost shrimp in the tank this evening in hopes that the "thrill of the chase" will spur her appetite, but I am not expecting much. <Perhaps the occasional earthworm...> Unfortunately, I have not given her any vitamins and just tried to vary her diet to provide the proper nutrition. <... read... where you've been directed. There are some very common deficiency syndromes with these (Chondrichthyans) fishes... as you will/would have found by now>   Can you recommend something that can be added to her food (when she starts eating again) to help her receive the correct balance of nutrients? <Hello... this is posted... see WWM...>   Reference the proper medication, I understand that Freshwater Rays are particularly sensitive to medications and I have never tried to use any in this particular tank.  Could you recommend a particular product? <...> Also, the one test that I am unable to perform, is to determine if my PH has dropped too far below 6.0.  My test kit only shows the PH reading to 6.0 and I have been unable to find any type of standard test kits (i.e. test tubes, liquid, litmus paper) that provide a lower gauge.  Could any of the Crew recommend a good quality electronic/digital PH tester that's not to costly? Thanks again for your help. Regards, Steve <Please, don't waste our time... Read. Bob Fenner>

Hystrix ray - 10/17/06 Hello <Hi Emma, MacL here with you today.> I recently purchased a hystrix ray and am wondering if it is safe to feed freshwater stingrays red wiggler worms? My stingray is in a tank with discus so I need to be sure that these worms are safe for them as well. <In my experience its best to stick with ghost shrimp to feed them. I do know some people who have fed them blood worms and the discus as well but I find that the rays thrive with the ghost shrimp and you can give the ghost shrimp things to eat that make them more nutritious.> Thanks Emma

Feeding freshwater stingrays  - 08/15/06 Hello Brian here I wrote a few months ago about getting into freshwater sting rays. Anyway I have only a few questions for you this evening.  I purchased 2 freshwater motoro rays and they are doing great eating well and look to be in good nutritional and physical health.  Their color is great and they are very active looking for food. <Beautiful animals>   When I purchased them 3 weeks ago they were eating live red wigglers and live black worms.  The problem is no stores in my area sell these items and that fish place will not ship them to me. So I tried feeding them frozen blood worms and they got all excited that they were being fed but they would not eat them.  I was told when the rays got hungry enough they will start to eat them <Should... best to train by mixing "some live, some frozen/defrosted" for a time...> but this does not sound right to me.  The other question is the motoro rays are about 7 inches in diameter and in good health the water is kept identical to the dealers Ph 7.5, <I would lower this in time. Please read here: http://www.wetwebmedia.com/FWSubWebIndex/fwstingrays.htm and the linked files above...> ammonia 0, nitrate and nitrite about 0 with MINOR changes nothing to worry about.  My tank is a 220 gallon with ProClear aquatics sump and an in line chiller (if not the tank would get about 84 degrees) <This actually is a good temperature for this species>   Is this a sufficient tank set up for these types of rays. <Mmm, not for very long... gets to be about a meter in diameter (and 15kg in weight) in the wild...> Last question I understand rays do not like high amounts of light so instead of running many fluorescent bulbs I only run 2 one on each side of the tank is to much light or not enough <Good> (the rays do not seem to mind the 12on12 cycle I have them on). I appreciate the help you guys are great. <Let's summarize: I would lower your pH, raise temperature, and see about mixing some live with non-live foods to train your Motoros. Ultimately get a much larger system... Bob Fenner>

Re: Feeding freshwater stingrays   8/16/06 Hey thanks Bob I appreciate the help and will be sending pics of the Motoros in the near future. <Please do>   Due you know any online sites that ship or sell live black worms? Thanks again.   <Yes... try Paul Dover at Bayou... bayoubrine@aol.com Bob Fenner>

Freshwater Stingrays, Sabrina's Envy - 12/15/2005 Around 6 moths ago after 15 years of fish keeping I decided to try freshwater stingrays. <I envy you.  Deeply.  You've no idea how much I love these animals, wish I could keep, breed....  Not in California.  Sigh.> The most frequently available and affordable to were Potamotrygon reticulatus. <Beautiful.> I set up a 6' x 2' x 18" high tank filter using 2 canister filters - an Eheim 2213 and a Fluval 304) with a sand substrate about 1/2" thick. The pH was and still is 7, temp 80degrees C, ammonia zero and nitrates controlled with weekly water changes. <Nitrite, I trust, is zero as well.> About mid June I purchased 2 Retics (only males were available) about (XX)" dia <Unfortunately, portions of your email are garbled....  the lettering I can figure out, but this is impossible for me with your numbering, unfortunately; not sure what happened here.> and settled them into the tank with the intention of getting 2 females at a later date. These 2 males settled within the hour and were eating earthworms the same day.   <Wow, excellent!> About the end of October the shop finally got more retics in and I got (XX) <Same trouble....> females again about 2" dia. The males are now about (XX)5"-4" <I'm assuming this is 3.5-4 inches?  Blast this webmail....> and the females were added to the same tank. <Yikes!  I'd've quarantined the newcomers, to be sure....  there's just SO much that can go wrong with rays....> Although I could see no problems between the rays the 2 new females have not settled like the males and do not seem to be eating anything I put in the tank. <VERY bad news....  At this tiny, tiny size, they may not make it without food urgently....> I have tried blood/earth worm, prawn, mussels, flake, tablet and I have even tried Live deformed Endler's guppies (which is normally a big no no for me) all without success. <Try live bloodworms, failing that, try live blackworms.> I am now at a stage where I have placed a divider in the tank as one female is extremely skinny (hollow in the head and showing pectoral bones) and the other seem not as bad but fear it will go the same way. <Very, very dangerous....> I feel the possible mistake has been adding them at different times and if so then lesson learned as I feel I will lose these 2 females. <I fear you may....  The urgent lesson here is QUARANTINE your newcomers....  Not only to protect your existing, healthy stock, but to help the newcomers chill out and eat.> Sorry for the length of this mail but the more info u <Not 'u', 'you'....  we have to correct these for posting on the site.> have the less speculation you will need to make. <Quite correct.  Thank you for the detailed info.> If you can help or advise it would be appreciated. <I would advise removing the females to a separate quarantine system if possible - and NEVER add to your main tank without a four week quarantine for new rays.  If these girlies don't make it, I will also *strongly* advise that you start with slightly larger specimens next time, and make the shop owner show you the animals eating prior to purchase - if they don't eat, don't buy.> Thanks,  Stuart,  Scotland. <Thank you very much for sharing, Stuart - Keep up hope, and try to get some live bloodworms or live blackworms into these girlies.  If you get them to eat, keep them eating - get 'em fattened up a bit before you wean them off onto dead or prepared foods.  All the best to you,  -Sabrina>

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