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FAQs about Sea Slugs, the Opisthobranchs, Stocking/Selection

Related Articles: Sea Slugs, Nudibranchs,

Related FAQs: Seaslugs 1, Seaslugs 2, & FAQs on:  Seaslug Identification, Seaslug Behavior, Seaslug Compatibility, Seaslug Systems, Seaslug Feeding, Seaslug Disease, Seaslug Reproduction, & Marine Snails 1Marine Snails 2Marine Snails 3 Nudibranchs, Nudibranchs 2, Nudibranch Identification, Nudibranch Behavior, Nudibranch Compatibility, Nudibranch Selection, Nudibranch Systems, Nudibranch Feeding, Nudibranch Disease, Nudibranch Reproduction, Berghia Nudibranchs, Snail ID 1, Snail ID 2, Snail ID 3

Chromodoris willani.

Lettuce Nudibranch; stkg., comp.       9/16/15
WetWeb crew,
First thanks fir reading my email. I just recently starting adding lettuce Nudibranchs to my 75 reef. Added the 2nd one after I lost the 1st one.
<These/Elysia; do "just die/dissolve" mysteriously>
I check levels daily. So I think I can rule out water quality, but after a few days they just have "disappeared". My tank consists of 1 yellow tangs, 3 green Chromis, Ocellaris clown and purple Firefish. I have a typical cleanup crew, snails and herm. Crabs, but have a territorial coral banded shrimp. Is this potentially my culprits?
<Oh yes; most prominently the Stenopus; but depending on the species, their hunger, Hermits can be/come opportunistic as well. I would not stock Sea Slugs here>
Any information you could help with would be great. Thanks again! Sincerely,
Bryan Varone
<Thank you for writing/sharing. Bob Fenner>

wall street journal query on sea slugs    2/11/13
Mr. Fenner,
<Barry, what happened to proper nouns?>
I'm a reporter for the wall street journal in new York, wondering if you might fill me in on the sea slug market.
I've seen some items on the web that suggest there may be an interesting general interest story to do about their sale and the challenge of keeping them.
<The challenge, yes; but most groups of sea slugs/opisthobranchs are very slow, no sellers in the ornamental trade. Only a few Aplysiids sell nowayears>
if you have a minute, I'd be grateful if you could tell me how i can reach you by phone and when it might be convenient.
many thanks
<Would be better to just write queries, responses. Lest there be misunderstandings. Bob Fenner>
Barry Newman
Re: wall street journal query on sea slugs    2/11/13

I'm a throwback to the days of all-caps wire machines. sorry about that.
I'm just starting on something i know absolutely nothing about, obviously, so it's difficult at this point to ask you narrow questions. but here's one: i see Nudibranchs <No 'e'> for sale on the web, on sites like this:
<They are poor sellers, that rarely live for any period of time... days to a few weeks. See WetWebMedia.com re... need very specialized foods, culture>
if nobody is selling, i wonder what this site is, who runs it, who buys from it etc. etc? if you'd like to help--not for attribution if it's easier--please let me know.
many thanks,
<Keep reading. BobF>
Re: wall street journal query on sea slugs    2/12/13

<Mr. B>
They are "poor" sellers, yet they are still being offered for sale on the internet.
<Yes; "one out of many" species, groups of unsuitable organisms offered in the trade... sorry to state>
That would suggest to me that there are also some "poor" buyers out there.
<Some, not many... the real story if I may, is the unbelievably high turnover (a euphemism for sure) of hobbyists/customers in the aquarium interest (about 100% per year) due to this/these sort/s of poor practices in our industry... Folks "getting bummed out" to the point of quitting due to lack of success, anomalous losses>
 That would be a story, if I could locate anyone uninformed enough to have bought a Nudibranch.
<You have strong intuition. A good quality. B>
The beginning portion of my paper 02/13/13

      I apologize if the paper is slightly rough, and want to extend to you my most sincere thankfulness for your willingness to read this. I probably will need greater depth added in certain areas, please let me know where those would be.
<Well; a bunch to return to you here. Suggested changes in brackets, in red... Bob Fenner>

Hello! I am interested in getting Tridachia crispata, and Nudi sel. -- 4/17/09
I have a 55 gallon with plenty of hair algae growth. I know that you need to cover all powerhead intakes. The only pump in my tank is a Koralia 3. Would the small, black, plastic bars be enough to keep the slug from getting puréed?
<Mmm, maybe... I'd be careful re the placement period... if this slug becomes "free floating" it could well be sucked up against any intake>
Should I get a plastic mesh screen? Also I saw a Glossodoris sedna for sale. Can they be kept happily in captivity?
<Not often the case with any Nudibranch, no...>
Is it better if they are left in the ocean?
<In the vast majority of cases, yes. See WWM re providing for such.>
Thank you for your time.
<Bob Fenner>

Shrinking Lettuce Nudibranch  12/8/08 Hello WWM Crew, I purchased a Lettuce Nudibranch about a week ago to take care of some small patches of hair algae that won't go away. <Mmm, this, and other "algae eaters" don't "eat all" types of algae... Very often one encounters what you detail here...> It stayed on one rock for a couple of days and then started to cruse the tank (200 gallon reef). I woke up this morning to just the head which it is still alive and continues to move about the rock work. I haven't been able to find any information on whether this is normal or not... or if something in my tank caused this (Overflow, Crab or Fish). Thanks Nick <Mmm... could be a predator... or the gear as you suggest... In this size/volume system I'd leave it be... hope for the best, see if it regenerates... As to the algae, I'd seek other means (competition, nutrient deprivation...). Perhaps a cursory read here: http://wetwebmedia.com/algaeasfriend.htm and the linked files above... Your system, from your excellent photos, seems to be very healthy... just a bit more nutrient rich perhaps than it should be... Increasing RedOx here, in a few possible ways, might be the window/avenue to pursue. Bob Fenner>

Death to Caulerpa! Hey all, Everyone here has seen my tank. It's a pretty nice tank, and I am proud of most of it. Well, perhaps I should rephrase that. I am proud of everything except my Caulerpa. Grape and Parasail dominate my tank. The grape hitch-hiked on my Ritteri's foot, the Parasail literally grew out of the rocks. I saw it as benign, and left it. Huge mistake. For several months now, I have not seen my rocks. The Grape really does not grow too much, but the parasail does. It covers the rockworks, and has smaller stems and tough roots, making it impossible to extricate.  <I lived through this same problem quite a while ago. Aggressive manual removal which included hand picking and a stiff bristled scrub brush along with dropping the temp allowed grazers to get ahead of it.   Eric Borneman wrote a phenomenal piece on the specific nutrient ratios that favor certain "algae", Cyanobacteria, Dinoflagellates, etc. It is hard to find (I recently looked and came up empty). If you can find it, it has some very useful information that could be used to develop a strategy based on manipulating an easily controlled nutrient (Nitrate perhaps).>  It grows over my corals, imbeds its roots in their flesh, and starves them of light. It grows around 4 to 5 inches a day, and will not go away. Daily I pull out about this much:

I have just recently acquired a 6" Sea Hare from IslandReefs.com. The owner there, Tom, says he feeds them Caulerpa as they have run out of hair algae. Sadly, I have yet to see mine even notice the stuff! He just glides right over it without a second glance...eats my Ulva sp. Seaweed, my Nori, my Seaweed Selects, and my Hair Algae, but not my Caulerpa. Tom swears they do, but I have yet to verify that. <I have also heard the claim that these guys will eat Caulerpa, but I would try and find out which kind they actually did eat. With such a noxious battery of defensive chemicals, it is very likely that some might be more or less palatable. Also, it is likely that Caulerpa will only be consumed as a last resort. If other foods are offered or available, they would be eaten first. So, you may have to starve the See Hare into eating it.> What other means are there of naturally controlling Caulerpa? I do know that a specialized species of Sacoglossan Slug, Oxynoe viridis consumes Caulerpa and Caulerpa only. I also know that no online vendor or local vendor sells them. Help! I HATE MY CAULERPA! Mike Giangrasso <You could take your cue from the loonies about San Diego bay and in Australia and put a big tarp over it... Oh, No! Even better.... blast it with bleach. Wait! Huge doses of Copper Sulfate delivered with a fire hose! OK, all of those ideas would kill everything in your tank, just like they killed everything in the immediate area they were applied in the wild. And for our next stupid human trick, we'll rid Hawaii of chameleons by exfoliating the whole place with Agent Orange (the herbicide, not the 80's Orange County surf-punk band). Sorry for the sarcastic rant. As for the O. viridis, try IPSF, Inland Aquatics and do a search on RC. Those are your best bets. Hope this helps.  AdamC.> 

R4: Vacation - Power Failure - Nuclear Holocaust, and Aplysia sel. -- 09/26/08 Doh! Sorry, Eric. I was reading a post by Neale and I guess his name was in my head. <<LOL! He writes some informative and memorable posts for sure'¦I should be flattered to be confused with... No worries Andy!>> Thanks for your help (again). <<Always welcome, mate>> I am not wavering--I am committed to going fishless for 4-6 months. <<Great!>> I was looking in my sump and tank this morning and saw lots of pods crawling around, so I am very happy. <<These will recover quite quickly with the improved conditions. And I know you said you were not feeding the tank, but these critters (mainly Amphipods and Mysids) are very predaceous, to the point of eating their own. I have found that a few shrimp pellets every day or two tossed in to the sump and refugium can go a long way towards boosting populations>> I also opened up my fuge to take a look and boy oh boy has my Chaeto grown since the crash. <<Ah'¦no doubt>> My 30g fuge was jam-packed, side to side, top to bottom, with Chaeto. I thinned it out by about half (I usually trade this to my LFS for store credit, but they are such a pain to deal with . . ..,I just decided to chuck it). <<Excellent'¦but too bad about your LFS'¦some folks are just short-sighted>> I set my light cycle at 6 hours for the MH and 8 hours for the actinics (usually I run 9 hours and 11 hours, respectively). <<I see no reason not to go back to your normal schedule'¦is closer to a 'normal' tropical cycle too>> The Astraea Snails I added are doing a good job of eating the algae that's accumulated on the glass. I was thinking of adding a Caribbean Sea Hare to this mix, as I have had good success with them in the past. <<Mmm, okay'¦then perhaps you already know to be cautious of getting a 'temperate' species'¦often sold as 'tropical'>> My skimmer is still pulling a decent amount of skimmate, so clearly dissolved organics remain. <<Don't ya just love skimmers!>> Take care. Andy <<And you my friend. Be chatting, Eric Russell'¦(not Neale [big grin]) >>

R5: Vacation - Power Failure - Nuclear Holocaust -- 09/26/08 Eric-- <<Andy>> I want the entire FAQ's for today to have the heading "Vacation - Power Failure - Nuclear Holocaust", so I'm going to respond to you yet again ;-). <<Ha! We're well on our way!>> Actually, I believe it was you who taught me long ago to feed my fuge/sump with shrimp pellets, and I have been doing that since you taught me and since the crash (what I meant by not feeding the tank was, I'm obviously not doing what I normally would if there were fish/coral in the tank). <<Ah! Excellent>> I am well aware of the problems with the sale of sea hares. I have read such warnings here and in Calfo's/Fenner's Reef Invertebrates. <<Indeed>> The Caribbean ones are easy to distinguish from Aplysia californica, which unfortunately is what most of my LFS sell. <<And many others>> Whenever I see them on display, I make it a point to tell the owner that he/she shouldn't be selling Aplysia californica to anyone that doesn't have a temperate tank--they look at me like I'm speaking a foreign language. <<Not uncommon, I assure you>> I even had one self-professed expert LFS owner say "Really? They come from California?" <<dismal'¦>> Sadly, one of the more reputable vendors, That Fish Place, sells them and notes in their specifications that they come from the Indo-Pacific, which is clearly false. <<Perhaps you could send them a note re>> As I'm sure you know, the Caribbean varieties aren't as big or interesting looking, but that's no reason to buy them. << The Sea Slug Forum states that Aplysia californica has been reported to reach more than 30' in length! Aplysia morio can grow to about 18' though I don't think it is a regular in the trade'¦the smaller species you refer to is probably Aplysia dactylomela which grows to about 6' and is a much more appropriate species for reef aquaria use>> I will put my lights back up to a normal schedule and let the greening of the tank continue! <<Enjoy the adventure!>> Thanks again. Andy <<Cheers mate. EricR>>

Lettuce Sea Slug, as algae eaters...  -- 09/08/08 Hi all, I have read a couple places that lettuce sea slugs can be used to control green hair algae...is this true? <... by and large (in actual application in hobbyists systems, no... These slugs only eat certain varieties/species... and the types found in aquariums... are rarely amongst these. Bob Fenner>

Sea Hare Question (Should We Even?) -- 06/25/08 Good evening Crew (or good whatever whenever you read this). <<Hiya Andy>> I am confused about Sea Hares. <<Oh?>> I have some green hair algae that have cropped up in the last few months on my base rocks. I purchased a Kole Tang thinking that he/she would take care of it, but doesn't seem interested. <<Mmm, yes'¦it is my experience that most fishes (organisms et al) acquired for 'algae control' rarely ever do so to the level of our expectations'¦or do so only for a short time. It seems to me they quickly become acclimated to/tend to prefer the prepared foods offered in captivity. I've had my best luck by employing multiples of herbivorous fishes; in my case, five Tangs from four genera and a pair of Rabbitfishes (it's a 'big' tank). By doing this, not only am I providing a broader palate of appetites/tastes, but I think there is also some 'instinctive stimulus' to consume the available natural alga growth 'before the other guys' get to it. Unfortunately, the space requirement of these particular herbivorous fishes (Tangs & Rabbitfishes) precludes such methodology for many hobbyists>> My blue legged hermits seem interested, but I'd need about 100 of them to make a dent. I have tried just about everything to limit algal growth short of shutting off my lights for 3 days <<And is but a temporary measure>> --limit my feedings, <<But hopefully not to the detriment of your livestock>> employ a fuge with Chaetomorpha, <<Excellent>> limit my photoperiod, <<Of no practical value re the nuisance alga, in my opinion. I would not do this>> do weekly water changes, <<Mmm, in some instances this can actually 'fuel' the alga growth. Do test (both the make-up water, and the tank water before and after the exchange) to ensure you are not adding more fuel elements (Ammonia, Nitrate) than you are taking out during these weekly water changes. You may actually find two or three weeks apart to serve you better here. Aging the new water for a couple days, then adding a small amount of tank water (for the available bacteria/nutrient consumers) and aging a couple more days, may also be of benefit>> use RO/DI water, <<Very good but have you tested your salt mix?>> yada yada yada. Ammonia, nitrites, nitrates, phosphates, silicates test 0, <<Am sure you are aware these may well be present but rapidly utilized/stored by the alga/other organisms to levels below what the test kits can register>> pH is 8.3, SG is 1.026, Temp is 79-81, calcium is 420, Alk is 3.5 mEq/L and magnesium is 1200. <<All good'¦>> I've been reading on Reef Central about all these great successes with Sea Hares. <<Mmm'¦>> So I research them on WWM, only to find out that most of the Crew that has addressed them doesn't think they are a good idea because of the potential to unleash Weapons of Mass Destruction. <<Though a possibility, I am of the opinion that this is a small concern unless the animal is attacked'¦and even this I consider unlikely, with most of the organisms/fish species associated with and kept in captive reef systems. My issue with using these animals is that effective or not (mostly not, in 'my' experience) at consuming the nuisance alga, they most always die (usually to disappear without a trace) in short order. Even in systems with a seemingly abundance of food, it seems they just don't get the nutritive requirement needed to survive>> I pulled out my copy of Reef Invertebrates to find out more, and although that book does have an entire section dedicated to these animals, it shows pictures of all the ones that are BAD for the tropical tank, <<Indeed, some 'temperate' species are collected and sold as 'tropical' animals'¦obviously another reason some don't survive captivity>> and no pictures of the ones that are recommended for the tropical tank <<Can't speak for Bob and Anthony'¦but I'm guessing there's a reason for this>><Mostly that these animals rarely eat much of the types/species of algae aquarists have/want them to... RMF> so even if I wanted to get one I'm scratching my head trying to make heads or tails of what's available. <<I see>> One fish store near me sells a "frilly sea hare" whatever that is--no scientific name listed (see attached picture). <<Looks like Aplysia californica to me'¦not tropical, and to be avoided for such reef systems>> That Fish Place sells a Blue Dot Sea Hare (Aplysia sp.), <<Possibly A. dactylomela'¦a tropical species>> a Flying Sea Hare (Aplysia parvula), <<Seems to be a small species (6cm) from the Philippines>> a Caribbean Sea Hare (Aplysia sp.) <<Possibly A. morio (a large black Sea Hare from the Caribbean), but more likely A. dactylomela again>> and, last but not least, just a regular old "Sea Hare", listed as Aplysia californica hailing from the "Indo-Pacific" (this store is supposed to have marine biologists on staff . . .). <<Mmm, see my earlier comment re this species>> I have a fairly peaceful 110g tank, except for my female Gold Stripe Maroon Clown that drives everyone crazy and is too fast for my net (to take back to the LFS) but maybe gullible enough for a #22 Caddis Fly. <<I have removed more than one troublesome fish using this methodology (a very small 'barbless' hook on 2lb monofilament and baited with a small piece of shrimp). This is especially affective for aggressive bullies that rush to the food first>> I run an AquaC EV-180, a 10 gallon sump, and a 30g fuge, and have about 110lbs of live rock. Any thoughts on whether a Sea Hare is for me and, if so, what specific animal should I be looking to use in a tropical tank? <<One of the tropical Aplysia species noted earlier may well do the job for you (like everything'¦no guarantees/certainties). But before you make the purchase, consider what you will do with this animal once the nuisance alga is gone (assuming it eats it'¦and doesn't just die/vanish). The decision to try is yours'¦and I too have 'heard' the success tales'¦but honestly, I am skeptical of these animal's true utility, or even suitability, to the hobby>> Thanks so much. Andy <<Happy to share. EricR>>

Re: Sea Hare Question (Should We Even?) -- 06/25/08 Thanks for your insight, Eric! <<Happy to share>> Here are the answers to your question: 1. By "limit feedings", I meant that I am very careful about the amount of food I am feeding--only enough for the fish to eat in a minute or two--and I am careful about what I feed--rinsed frozen Mysis, New Life Spectrum Pellets, live black worms, and Cyclops-Eeze flake. <<Excellent choices'¦and I like to expand my selection a bit further with frozen glass worms, frozen krill, frozen plankton and even the occasional pinch of quality flake food (e.g. - Ocean Nutrition) and of course some type of alga supplement (Two Little Fishies) as well as frozen rotifers, frozen Cyclops-Eeze, or similar for my non-vertebrate charges...all supplemented with the occasional splash of vitamins/HUFAs. Heck, my wife complains the reef tank eats better than we do'¦but the fullness of body, color, and vitality of my fishes speaks for itself>> 2. I have tested my RO/DI water and my mixed salt water (Reef Crystals), and both show 0 ammonia, nitrates and phosphates. I mix my salt water in a Rubbermaid trashcan and let it sit for several days before use (with a heater and power head). <<Okay>> 3. My lighting is 2x250W HQIs (14,000K) and 4 65W power compact "royal blues" (will be switching to actinics soon), and by limit photoperiod I mean that my HQIs are on for 9 hours, with my royal blues on for 11 hours. <<This is shorter than I like'¦though in all fairness, probably fine>> I have a good relationship with my LFS, so if I do decide to get a Sea Hare, I'm sure they will let me return it once its job is finished. <<Very good>> I'll let you know if I pursue this course of action and the results. Andy
<<Please do! Eric Russell>>

45 Gallon Fish Only Stocking 4/13/08   4/22/08 Hey Scott, <Hello Michelle.> Um...I bought a brown sea hare. <It sounds as though you already know the issues with this!> My LFS did not say that there were more than one species (they only had several of one kind in stock) so I don't know the specifics, only that it is smooth, brownish-green, is eating my brown algae and looks like a Hippo. And was duly named thus. I've sent a similar picture I found on the web, only mine is not as red because he eats brown algae instead of red. <I have no first hand experience with these guys, but am hesitant to recommend you try to keep it. Your tank is on the small side if the inking does occur and they are better suited to a reef setting.> But according to my LFS dude it is a peaceful sea hare with no problems in a peaceful tank (My LFS did not mention a thing about the inking. I'm glad my tank is peaceful.) I do not anticipate too many problems there, but I found out how to deal with it if it happens. <Good, be prepared.> I kind of don't understand about adding calcium and checking phosphates though. Is this something I should be doing on a regular basis now that I have the sea hare? <At least test calcium, Alk and nitrate every few days. This also assumes ammonia and nitrite are 0 and your salinity is good (1.025-1.026).> My main problem is that the sea hare seems to have a habit of coming to the surface. Is he trying to crawl out or is he just enjoying a breath of fresh air? <Likely just crawling around, looking for a place to go.><<Mmm, no... looking for an appropriate habitat. RMF>> Also, he appears to have taken a liking to the heater. Is this bad? <It can be. If your room temperature is high enough your heater may not be coming on at all, nor need to. In this case the heater is just another obstacle for the slug to crawl over. With heat radiating from the heater he should stay clear. One advantage of using a sump, remotely locating the heater.> To update my fish list, I have also added a copper-banded butterfly and a fire shrimp, since my LFS does not get in skunk cleaners over half an inch to an inch long. My fire shrimp hides a lot, which I hear is typical. <Yes, they do. I am sorry to tell you, but a 45 gallon system is too small for long term success with the butterfly.> The butterfly is thriving. I've been feeding (and seeing him eat with quite an appetite) frozen brine shrimp, and I got him supplements of sponge (since I have no live rock) which I'll be giving him twice a week. He appears to be at ease with his tankmates. He hides some, but I think he's still just acclimating. I've been thinking for a little while about some yellow or star polyps (only fluor. lighting); will he eat those? <He may, some do, some don't. Unless you have extra fluorescents you will have little success with these. The standard lights that come with a tank are just not enough for even low light corals.> I will soon add the Firefish and Banggai. The pajama cardinal is off the list and if I still have room I will add the royal Gramma, unless he's too aggressive for the copper-banded butterfly and sea hare to handle? <They can be aggressive. With your current stock I would call it good after the Firefish and cardinal. I believe in conservative stocking!> Thanks so much for the help, Michelle <Welcome, best of luck to you, Scott V.>

Uhh... inappropriate. A. californica

Sea Hare death(s)  04/14/2008 Thank you for a wonderful site. I apologize for asking a question when I'm sure the information I'm looking for is already posted but I seem to be handicapped in search engines as they always seem to return matches where every single word is accurate, yet somehow out of context. <Ah, yes... GIGO... a need/arena for learning the field/terms, use of Boolean logic... as it applies to such searching perhaps> I have a 90 gallon marine tank FOWLR containing a Yellow Tang, Blue Tang, Coral Beauty, Six line Wrasse, 2 percula Clowns and 3 blue/green Chromis. I started seeing string hair algae of the kind no fish eats (naturally) and by the time I recognized I had a "problem" rather than a simple "event" the algae had taken a pretty strong hold. I corrected the problem (phosphates and a bit of overfeeding) but the algae remained. On the advice of a local pet store I purchased two sea hares <Mmm, what species? Too often cold-water species are offered...> and they went to work immediately! Not only were they in the process of cleaning the tank nicely but I've decided that they are at LEAST as interesting as any fish, so I was looking forward to a long an happy relationship. I came home from work one day to find one of them dead .... with a huge split right up the center of his back, all the way from the vent hole to the neck. Without a picture the best way I could describe it would be if you could imagine a pressure split along the seam of a plastic bag as opposed to any sort of gash from an attach or contact damage. I took him back to the store to see if they could explain what went wrong and they said ... stop me if you've heard this before ... they've never seen that before, never heard of that before, can't imagine any animal or event that caused that and would I like to buy a replacement? <Mmmm...> (um ... not at this time, thank you). Two weeks later the remaining Hare was busy at work at 10 am and dead of the same cause at 2pm. The precision of the split (no rough edges at all) and the symmetry of it (right down the center of the back) as if sliced with a scalpel are very troubling. Do you have any suggestions? Thank you, Gil (not a pun!) <A need for a ready identification. Please read here: http://wetwebmedia.com/seaslugid.htm I suspect you have/had non-tropical species... that don't live in warm settings. Bob Fenner>

Lettuce Sea Slug 3/10/08 This question is for Scott V. I have a 28gal reef tank with a few peaceful fish and was wondering how hardy lettuce Nudibranchs were? <Not a true Nudibranch, actually a slug. These do tend to be a hardier selection.> I would really like to keep them but don't want to just watch them die! <The question is one more of food supply in your tank for the slug. A link to a great article on these for you below.> Please help thanks. <Welcome, I hope this helps, Scott V.> http://www.advancedaquarist.com/issues/oct2004/invert.htm

Sea Hare/Systems 2/28/08 Hi <Hello> I was thinking of purchasing a sea hare, however I am a little concerned with the fact they produce poisonous ink. If none of the other fish provoke it could it still ink? <Possibly, and can release the ink upon their death.> What would happen if it was to die would the ink be released? <Could lead to the death of other inhabitants. I very good chemical filter is needed to remove this compound if released.> I have a 180 gallon reef tank with a Clown Fish, Yellow Tang, Hawk Fish, Sleeper Goby, blenny, and various corals and a few different kinds of shrimp. Would this be a good set up for a sea hare? I have an abundance of algae. <Adam, these animals are very difficult to maintain and I would discourage you from getting one. It will eventually die and cause problems for you.> Thanks, <You're welcome. James (Salty Dog)> Adam

Aiptasia & Sea Hare comp.... & Bio. alg. contr.    2/3/08 Although our 55 gallon FOWLR has been doing fine (fish growing & happy, no death, stable water) I have three nickel sized Aiptasia and some hair algae. Can/will the sting of an Aiptasia injury or kill a Sea Hare? <Won't be the best combination but certainly not the best solution for both problems. For the Aips see here: http://www.wetwebmedia.com/marine/inverts/cnidaria/anthozoa/aiptasia/aiptasia.htm. And the causes of the Hair Algae must be addressed first. The Sea Hare will just be recycling the nutrients the algae use. Read on Nutrient export etc. Olly>

Re: sea hare, stolen image/s (we don't post), coldwater animals misplaced in tropical settings   2/1/08 probaly <?> not eaten sense it was larger then all the fish in my tank about 3 inches. I am attaching a picture of what it looked like but mine was greenish tan <... this is a "lifted" as in stolen image of an Aplysia californica... a cold water animal... Misplaced if this is what you have. Please, read here: http://wetwebmedia.com/seaslugcomp.htm and the linked files above. Don't write us, read. Bob Fenner>

Help! Dead sea hare, wilting LTA, high nitrates 11/08/07 Hello WWM, I hope you guys can help, I have searched your site and can not find anything near what happened to my aquarium today. I have a 75 gallon with the two clowns, LTA, a yellow tail damsel, Chromis, royal Gramma, snowflake eel, choc chip star, and Bahamian star. <What species is this last?> Everybody has been living together peacefully for 3 months. The system has been running for 6 months. I have 3 powerheads, 75-80 lbs live rock, crushed coral as substrate. On Sunday I added a sea hare <...? What species? Many sold are coldwater> to help control some algae. Today I can home from work to find him sucked into one of my powerheads, and my CC star eating him!!! <... not uncommon> I got the CCstar off and took the powerhead and sea hare out. I was unable to completely get the sea hare out of the powerhead so I just threw the powerhead out so I wouldn't contaminate my tank by putting it back in. <?!> I immediately checked all my levels and found my nitrates had risen. 2 days ago my nitrates were 0 and now they are at 10ppm. My ammonia was 0 two days ago, now it seems to be between 0 and 0.25.(which I expected to rise due to a dead critter) Nitrates:0 Phosphorus:0 pH: 8.2 specific gravity: 1.023 <I'd raise this...> I am assuming I need to do a water change, however will be unable to until tomorrow. I just did a water change a week ago so I don't have any RO/DI water on hand. (lesson learned about having reserve water!) When I got home my LTA was spread out and looked perfectly happy. Now, about an hour after I removed the powerhead and dead sea hare I noticed my LTA has begun to wilt and start to deflate. Everybody else seems perfectly happy in the tank, at this time. I have not fed the tank or done anything else to it. Am I just overreacting to my LTA's behavior? Could it possibly miss the powerhead? Or is it due to the sea hare disaster? <Much more likely the two former...> What is the best thing I could do right now? PLEASE HELP!!! Thank you for all your wonderful help and wonderful site. ~Michelle <Welcome. I would do nothing overt here. Likely all will be fine. I'd clean up and return the powerhead. Bob Fenner>

Elysia viridis. Looking For A Bryopsis Grazer - 05/06/07 Good Morning all, <<Greetings>> I have been working on a Bryopsis problem for a while now and have been doing regular water changes to combat the situation. <<Have you looked through our info re nuisance algae?  Raising your system's pH to 8.5/8.6 and keeping it there for several weeks has shown anecdotal proof of helping to eliminate this pest alga>> My battle has lead me to research additional means. <<Ah...ok>> I have found that a sea slug of the order Sacoglossa, Elysia viridis, has made claims to eat Bryopsis exclusively. <<Mmm, not "exclusively"...at least not according to seaslugforum.net>> The problem I am having is finding this slug in stores? <<I think this animal is more a cool/temperate species than a tropical species, based on its distribution in the Northeast Atlantic>> I have been told my LFS that the Lettuce Sea Slug is the same thing as the Viridis, however I am not sure if they are. <<Elysia crispata (Lettuce Sea Slug) is a distinctly different species from E. viridis hailing from different locales...and quite apparent when viewed>> I know they are of the same family but not the same species? <<Correct>> Can you help me decided on whether or not to buy a Lettuce Sea Slug for my battle, or if not, where I can obtain an Elysia Viridis? <<I would NOT buy the Lettuce Sea Slug.  Little is known of what these animals really eat (even though they are actively marketed/sold as grazers of "hair algae").  Many of these slugs are able to harbor the living chloroplasts of the algae they consume which continue to photosynthesize within the body of the sea slug, providing it with sugars for its own nutrition.  E. crispata have been found to contain the ingested symbiotic plastids from Halimeda incrassata and Penicillus capitatus...hardly "hair" algae.  My own anecdotal observations and experiences would seem to bear this out as I have never known one survive more than a few weeks to months in a home aquarist's system, even with an abundance of hair algae present, as they all seem to ultimately shrink and die from starvation.  I think a better choice of slug to try would be from the genus Aplysia...the Sea Hares.  These slugs; at least in my opinion/experience, are more hardy and much more likely to consume the filamentous algae than E. crispata>>   Thank You for Your Time <<Happy to share.  EricR>>

Sea Angels... pteropods... opisthobranchs...  - 05/10/2006 Hi, < Hello! > Can you purchase a Clione for  a pet ???? < I have never seen them on any list of availability. > Is it legal to have them in the United States . < I am not sure about that one. >   I would love to have one, they are so relaxing to watch them swim around < They may be obtainable through scientific supply houses. I strongly urge you to learn about their feeding habits, and learn how to raise their food first! There is more information to be had at http://en.wikipedia.org/wiki/Clione . > Cheryl Chafatelli

Sea Hare Splitting? 10/23/06 Hi WWM crew, <Hello Ryan> I have a 35 gallon saltwater tank. There is a Coral Beauty, orange star fish, three crabs, and a Sea Hare. I woke up this morning and I saw my Sea Hare's skin splitting down the middle. There was something that looked like a white larva where the skin split. I took out the Sea Hare and moved it to a quarantine tank, because I heard they can kill your other fish when they die. <Indeed.> It hasn't moved around in the quarantine tank so I think it's dead. Do you have any idea of why it did this, or how I can prevent it in the future? <Most Sea Hares, if not all, are very difficult to keep.  Should only be attempted by expert aquarists.  They do not appreciate bright light and are algae grazers.  I'm quite sure none of these conditions exist in your tank.  Try something a little more easier to keep in the future.> Thanks for your reply! <You're welcome.  James (Salty Dog)> Ryan Forsman

Sea hare sel., comp.  12/30/06 OK, so after moving my tank (150g Berlin, 250lbs live rock, light bio-load) I had a huge outbreak of long green hair algae. Covered everything. Tried cutting back on the light, but I only achieved making it's color less attractive. After reading all I could, I decided I didn't want to go with scraping, chemical, etc....but add a natural solution. When weighing out the pro's & con's of such grazers, I settled on a sea hare, <Mmm, what species?> as it seemed to be the most voracious grazer. I wasn't so worried about it dying, as my tank is quite healthy and there is much for it to eat....... but with such a nocturnal creature, how on earth would you know if something that you rarely (if ever, lately...) see? <Mmm, the results of their night-time foraging?> Also, in a 150g, how much pollution/death could I be facing if I do not find the body? <Could be appreciable depending on the species, size... your filtration, maintenance...> 250lbs of rock is a pretty sizable pile to dig through. Thanks in advance, my briny friends!   -Pat <Do take care to try a tropical species (not a cool/coldwater one), that is, and stays small-ish. You have read here?: http://www.wetwebmedia.com/algaeconMar.htm and the linked files above? There are other "biological means" to consider... Bob Fenner>

Greek Goddess I went to my local fish store and seen a Greek goddess it was deep blue and purple. I have never seen colors so bright before. Is this creature a slug, snail or what? <yes on all counts... AKA shell-less snail, sea slug> also is it reef safe? thank you frank. <tough to say...no one can keep them alive. If your LFS ordered this animal (as opposed to having received it on substitution/without ordering it) the I have little respect or regard for their irresponsible business practice. Please admire this animal from photos for now. Anthony>

Tank Update and Nudibranch Question (refugium and algae control FAQs) Hey Bob, Just wanted to give you an update on my tank. My nitrates are down to 30 after 3 weeks of weekly 25% water changes. Am still battling some hair algae but everything seems to be doing well.  <Ah, good> Since I have some left over money I have decided to buy a CPR hang on refugium. I want to put some of my remaining tang heaven and get some more algae to help me export more nitrates. Have you ever used one of these units or have you herd anything about them?  <Yes, we have some of Suk, Tom and the boys from Arcata (CPR) refugium units on test tanks... with about the same CF lighting we all use... We've been building, using very similar gear (ours have skimmers, calcium feeders on them in addn.) for years... these do work> Also, I have been seeing algae eating Nudibranchs advertised on several web sites. (some call them sea hares) The also say that they are easy to keep. Is this just a marketing ploy or do these really eat hair algae and easy to keep?  <IMO/E more of the ploy... don't like the use of Aplysiids (Seahares) for this application... can/do cause some real troubles with water pollution at times... Would look to other algae eaters> I certainly wouldn't want to buy one to have it starve and die in my tank possibly killing all of its inhabitants. Thank You, Jonathan Pac <Good point... Do read, re-read the most recent updates on "Marine Algae", "Algal Filtration", "Algae Control" on our site: www.WetWebMedia.com here. Bob Fenner>

Sea hare?... pass 4/12/04  Hi There  <howdy>  My LFS has sea hares they are selling for which they claim is algae and Cyano control. I have heard before that the sea hares can consume Cyano.  <some do>  These dudes are real ugly rock like critters. Do they really help control red algae/Cyano??  <its likely a moot point. The few sea hares that make it into the aquarium trade are typically temperate species (cool waters). They are naturally short lived to begin with. Not a safe or recommended choice IMO. Furthermore, they would be treating the symptom (Cyano) and not the problem (nutrient control). Focus on the latter my friend... we have many recommendations for this in the archives. Do a keyword search from our home page at wetwebmedia.com for "Cyano", "sea hares", "nutrient control", etc. Anthony>

Waging war on hair algae Bob, <Mike G here> I wanted to get your thoughts on introducing a Sea Hare to take care of some painful green hair algae? <Sea Hares are wonderful consumers of hair algae. It may aid you in physically removing algae, but will certainly not solve your problem single-handedly. They are messy eats, and minute particles of Hair Algae WILL get released every time they take a bite. Also, their feces will contain partially digested hair algae, and possibly hair algae spores. A sea hare would be a wonderful warrior in your battle against hair algae, but you need to also eliminate the problem that is causing the algae in the first place.> I've had the aquarium up 8 years and have never had a battle like this with hair algae - I feel I'm starting to lose the battle. <That's a very common feeling when one is pitted against hair algae. I had problems with it when I first started my tank (15g). It was completely eradicated by doing 2 gallon (10%) water changes every other days and by adding a refugium of 25% of my water volume (5g) to my system.> It's been going on 8 weeks now. I've seen 2 Sea Hare species for sale: Aplysia punctata & Dolabella auricularia. Fosters & Smith rates Aplysia punctata as extremely delicate/expert with serious negative affects from possible ink secretions. Aplysia punctata isn't found on WWM. <I recently purchased a Sea Hare to control my Caulerpa problem. The only species available was Dolabella auricularia. I can assure you that he does a godly job on Cyanobacteria, Bryopsis, bubble, and pretty much any microalgae he comes across. I think that if he were to come across hair algae, he would eat it with gusto. Of course, he does not eat Caulerpa. It figures.> Dolabella auricularia is mentioned twice on WWM and a seller of it praises its traits without a mention of any issues with the species. I know it also secretes ink as well, but what about hardiness? Would you pick one over the other & how toxic is the ink? <Mine has "inked" in my tank twice now...either time with absolutely no negative effects. Granted, I do run a skimmer that is quite large for my tank (CPR BakPak), and I did a 10% water change as soon as it inked. Upon researching hares, I have found that Aplysia produce a considerably more toxic ink than Dolabella. I think a Dolabella would be the way to go if you decide on getting a Hare. As a side note, the hare toxins can be easily removed with carbon and a water change.> For back ground, I've been following all the algae reduction husbandry: All water changes & evaporate top-off done with buffered/aerated RO water from Kent Maxxima Hi Silicate (changed out all membranes 4 months ago), 30% water changes every 2 weeks (every one now), thaw, rinse & strain food prior to feeding, careful not to overfeed, 1800+gph turn over, over-powered skimmer (AquaC EV120), 45gal refugium w/ DSB & Chaeto, 520w PC lights that were recently changed, phosphates reading zero, but running PhosGuard as precaution. The green hair algae is still kicking my tail. I think I've narrowed down the original cause to a partially blocked line on my skimmer, which started the outbreak 12wks ago and then was fueled by a continuing die off of all my turbo snails (past email). About 6 weeks ago, 20 Turbos went through QT for a month - lost about 3 in QT. At the time, I thought it was just a natural/unlucky die off. Since they've been introduced into the main tank I've lost about 18. Originally, only the new ones seemed to go. My old ones are covered in coralline algae, so they were easy to tell apart. Now the old ones are going too, seems like one every 4-5 days and that's just the ones I can see. My 30+ Cerith & 40+ blue legs seem completely unaffected. My two "indicators" - RBTA and Hippo tang couldn't be better. I brought the Turbos in to help combat algae problem - now I think they're fueling it. I'm to the point now of thinking about taking all the Turbos out & putting them into QT. Any thoughts? <Certainly. If I were you, I would remove all of the turbo snails, as they do not seem to be doing anything more than providing nutrients for an algal bloom. It sounds as if your refugium is completely adequate, so you can't really expand on that. What really ended my hair algae infestation were 10% water changes every other day. This may be extremely difficult for you considering your tank and refugium sizes. However, It may very well be worth a try. You may also want to look into a high quality phosphate reducer. Lately, more and more people have been reporting success with PhosBan. It really all depends on what you think would work best in your situation.> I've been scrubbing the LR manually with a toothbrush & then immediately doing a water change to try and remove as much of it as possible. Last week I thought I delivered the final blow by spending 4 hours and manually scrubbing every single piece of my 180lbs of LR, one at a time, always submerged, in a bucket of saltwater from the tank. I used 3 separate buckets of saltwater to keep the algae export as high as possible. I certainly staggered it, but it looks to be getting back up. With the toothbrush method, do you think I'm doing more harm than good by spreading it around? My thought was that dislodging it and removing some though the filter & water change would be more effective than just letting it grow unabated. Any other advice? <I think that you are only spreading it more when you scrub it off the rocks. You are releasing minute particles into the water, which can easily find new places to lodge and form new "colonies" of algae.> Since I've been way too involved in algae recently, I wanted pass on a personal observation that the most productive hair algae remover in my tank is my Foxface Lo (Siganus vulpinus). After watching my tank for hours, he is certainly outperforming my robust lawnmower blenny and seems to be getting the better of my spineless clean-up crew. I've seen him wipe out 3 long sprigs of hair algae in a 90 second window. I just haven't seen him get much press for that on WWM or anywhere else and besides, he's a gorgeous fish and I haven't seen a single negative trait from him (having slightly venomous spines probably doesn't help him, but I'd find it hard to see how I'd get stuck by him). Just wanted to sing the Rabbitfish praises a little. <Rabbitfishes are well-known and wonderful herbivores. Glad to hear yours is working out for you.> BTW - wanted to get your thoughts on a sump/refugium I've designed and am thinking about having built. Especially concerning transition methods from one chamber to the next. I've attached the layout. As a note, the PVC return pipes in the refugium will be covered by a 6" DSB & the 2" ball valve into the refugium is designed to support complete gph control through the refugium. The overall design goal was to maximize the efficiency within the footprint & have an uncluttered/clean appearance. All my aquarium equipment is in the mechanical room below my office, so space isn't an issue. My current sump/refugiums were born from a series of upgrade bolt-ons over the years. Restricted water flow through the refugiums, wasted water volume due to in-line plumbing spacing & general clutter were the reason for the potential new sump. <I see no problem with your design for your sump/refugium.> So sorry for the length of the note - I just realized how long it is. Obviously, I'm excited about the hobby and can't express the gratitude in having the joint knowledge of WWM available to me and other enthusiasts. Get to me when you can & feel free to break the note up if it makes for easier reading. <The length of your email is not a problem. I can only hope that I have>

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