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FAQs about Plotosid Catfishes

Related Articles: Plotosid Catfishes

Related FAQs: Catfishes in General,

An eight inch plotosid in a captive reef system.

Engineer Goby tailing my clown fish 5/12/2011
I have a Red Sea Max 250 (60g.) saltwater tank. I have live rock, some corals, 1 six line wrasse, 2 clown fish, 2 engineer gobies,
<Pholodichthys? Get much too large for this setting>
2 spotted cardinal fish and 1 royal gramma. I also have some snails, a tuxedo urchin and some crabs and hermit crabs.
<What species are these crustaceans? See WWM re their compatibility>
My tank is about 3 months old.
I had bought the ocellaris clown fish as my first fish. They were a wonderful couple and got along well. Even though they were both the same size. Then due to a dead slug (or so I believe), one of them died. I bought a replacement partner and my 7 year old insisted on a black ocellaris. At the pet store, I saw engineer gobies and fell in love.
<A really neat species; a fave of mine... but grow to more than 18 inches...>
I know that my tank is smaller than their requirements, but they are still small and maybe I can upgrade when needed. Honestly, I just didn't know they needed a larger tank when I bought them.
One of the engineer gobies is hiding just like the description of the fish states. I actually barely ever see it, except when I catch a glimpse of it under the rocks in one of the many caves I created. The other one is acting oblivious to the fact 1. that it should be borrowing, it is swimming like a regular fish 2. that there is another engineer goby in the tank 3. and it seems to think it is a clownfish, because it is tailing the clown fishes all the time!!!! Is this normal behavior? I keep thinking that it has mistaken the black Ocellaris for another goby???
<Interesting speculation>
The clown fish both seem to be a bit annoyed by their stalker. What should I do?
<Like most adolescent behaviors of humans, indulge this fish for now... will likely "grow out of it" in time (months)>
Thank you very much in advance.
<Welcome! Bob Fenner>
Re: Crew@wetwebmedia.com, Plotosid, nee Pholodichthyid?  5/12/2011
<Mona... a fave island (Monkey)...>
I am sorry for writing to you before you even responded to the first email, but I have been looking every where for a good reason why my engineer goby is tailing the clown fish. I think I might have found the reason. Is it possible that this engineer goby is not really an engineer goby and is a Plotosid catfish?
<Mmm, still odd to "tail" other fishes, but yes, would be much more "out and about">
I read in one of the FAQ about the catfish that it might hit the other fish with its head while giving them a small dosage of the venom.
I looked closely on the pictures online and the difference I see is that this fish really has a catfish-mouth!
I have meanwhile put it in a floating separate tank in the tank and I plan to take it back to the fish store and give them a piece of my mind for selling me the wrong item (I carry much of the blame, because I did not notice the mouth earlier).
<Are very similar in appearance...>
The poor clown fish have endured enough pain!
They seem much happier since I isolated the fish.
Let me know if you think I am on the right track of thinking before I subject the fish to any more stress than I already have! (Bagging it and driving it to the store. I hope it survives the night in this confined space).
<Do take care not to get poked by the spiny portion of the pectoral fins>
Thanks again
<Again, welcome. BobF>

Coral Catfish (Plotosidae) Questions 6/25/2009
I just bought a coral catfish and I wanted to know your opinions on two things if possible.
1) How venomous are these guys on a scale of lionfish. More or less?
<I cannot cite sources, but anecdotal evidence suggests that they are more venomous than Lionfish. Definitely not appropriate for a tank where small children could get their hands in it.>
2) Do they have to be kept in schools?
<They do much better in groups of three or more Do read here:
http://www.wetwebmedia.com/plotosid.htm and here:
http://www.wetwebmedia.com/woundvenomf.htm >
Thanks for reading this.
<My pleasure>

Re: Coral Catfish (Plotosidae): More questions about venom. 6/26/2009
Thanks again,
<No problem.>
I have one more question to clarify something, could they be fatal? I read on one website that they could in rare cases. I am guessing that these people probably had a severe allergic reaction to them, right?
<I've never read about any confirmed fatalities, I have read more than one report of a trip to the hospital via ambulance from being stung by them. Any venom has the potential to be fatal under the 'right' circumstances, but yes, I would say that if someone was allergic, the reaction to the venom would be much more severe and significantly raise the potential to be fatal.>

Striped eel catfish, Plotosid repro.    4/10/09
Hi Guys,
<Hello Kylie.>
I love your website, my marine tank would be a shambles if it wasn't for our up to date information on fish breeds and how they live, thank you.
<Glad you like it.>
I was just on your "*FAQs about Plotosid Catfishes*" looking up for information on breeding these wonderful fish.
I am very curious as my female striped eel catfish was full of eggs, loosing her colour, and finding it hard to swim. I placed her into a breeding in-tank container,
<Not good, too much stress and natural spawning behaviour is not possible:
Typically the males dig holes under rocks for the females to lay their eggs in. It would be best to have the mated pair in a separate, well established tank with sand and rocks if you want to breed them.>
to where she laid over 70 eggs and passed away.
<Stress and fatigue due to spawning.>
Is this normal for the breed?
<Not as far as I know.>
The male, as I only had the two of them, now seems completely lost (I will be searching my LFS's for a few more to keep him company).
<They do best in groups (>10) as juveniles and pairs as adults.>
The eggs seem like they are fertilised,
<Was the male in the container, too? If not, they cannot be fertilized and can be removed.>
but how long would it take for them to hatch?
<Can't give you an exact number for this species, closely related ones need about 7 days.>
Would baby brine shrimp be suitable to feed them once they hatch?
<Given the relatively large size of the eggs and fry they'd be worth a try.
I'd also have Brachionus and some copepods available.>
Should I put the male in with the eggs?
<Now it's likely too late.>
I am sorry about all the questions, and thank you in advance for any help
you can give me =) Kind Regards. Kylie.
<Cheers, Marco.>

Breeding Of Plotosus lineatus (Coral Catfish) 1/29/08 I noticed a couple of threads on your marine Catfish FAQ re preggers Plotosus lineatus. Thought I would share my current experiences. <Great.> Added 3x small Plotosus lineatus about 18 months ago to 100 Gal FOWLR community tank. After a few months all 3 starting digging out cavity under rock to the bottom of tank. Over the last few weeks, one has become significantly larger than the other 2 and clearly the dominant member of the group, another became very large with eggs and the third became welcome but outcast at the same time by the others - appears a little beaten and scarred but still eating. Today eggs have been laid on the bare tank bottom in the cavity, with the largest member maintaining the eggs and guarding the entry to the area from other fish however the female does occasionally swim in and appears to stir the eggs around vigorously. If the eggs do hatch I will be surprised if they can last, getting any sort of food to the fry will be near impossible. <I have only read a couple reports on what you are experiencing. I'd keep good notes and try to get some good macro pics. May even consider writing an article with photos on this occurrence. I'm sure Mr. Fenner would be interested in this. <<Oh yes. RMF>> As far as raising the fry, I know of no one who has done such.> Regards <Ed, thank you for sharing your experience with us and do keep us posted. James (Salty Dog)> Ed.

Yellow eel tail catfish   6/5/07 Do you have any information on this freshwater aquarium sized fish. it is Australian i have been told. < Indeed it is Australasian. The yellow-tail eel catfish is a species of Plotosidae, that is, a catfish belonging to the same group as the marine striped catfish that used to be quite common in the trade. The exact species is unknown to me. The name is not recognized by Fishbase or any aquarium book I have, and is only used by a single fish farm's web site and they don't even mention the Latin name! It may possibly be Neosilurus hyrtlii or Neosilurus glencoensis, both of which have been traded as the yellow-finned eel catfish. Anyway, these catfish are all pretty similar, and while there are some dwarf species (15 cm or less) and some giant species (above 90 cm), most are 25-50 cm size bracket. The freshwater species outnumber the marine species, and in terms of water chemistry these freshwater species are not in the least fussy and will adapt to anything suitable for freshwater fish generally.> > put one in my cichlid tank and lost all of my cichlids. they died one after the other. do you think it would be disease or something to do with the catfish ??? i have kept these cichlids for approx 4 years with no previous problems. <Well, these catfish are extremely capable predators, and can and will eat anything they can stuff into their mouths. But they are also venomous, being equipped with one or more spines capable of delivering an excruciatingly painful venom. To be fair though, venomous fish rarely if ever use their venoms offensively, so the catfish wouldn't deliberately jam itself against a cichlid intending to kill the cichlid. But depending on the size difference, I suppose it's possible the cichlids tried to eat the catfish, and got stung that way. Regardless, the Plotosidae generally make acceptable tankmates for robust communities. The Plotosidae tend to be more or less gregarious, and at least when not fully grown seem to do best kept in groups. Some species will in fact pine away completely if not kept with companions. As they mature they become less sociable and expect secure hidey-holes, but even adults tend to be found in twos and threes in the wild, so getting a buddy or two for your catfish is probably a very good idea. Hope this helps, Neale> Re: yellow eel tail catfish  6/6/07 thanks...for prompt reply.... <No problem.> do you think the catfish has brought in a virus or disease that killed off the rest of my tank as the catfish is the only survivor now. lost rainbow sharks, cichlids and small catfish x2 all dead except the newly arrived catfish <Seems very unlikely. Viruses tend to be species-specific. Possibly a bacteria, but these tend to affect only certain fish and even in worst-case scenarios the fish get ill gradually and obviously. So you'd notice things like lethargy, loss of colour, dropsy, and so on before fish infected with internal bacteria or parasites actually died. Some fish have a toxic mucous (boxfish for example) but these tend to kill everything, including the boxfish. So I don't think that's likely. If the catfish was simply attacking things at night, you'd expect to see damage on the dead fish -- any sign of that? If you had an electric catfish, explaining the sudden deaths would be easier, too. But assuming you have a genuine eel-tail catfish of some type that's not a possibility either. Obviously you need to check water quality and chemistry. This may be a case of two unrelated events merely connected in time: i.e., you introduced the catfish at the same time your aquarium crashed for one reason or another.> regards tom <A picture of the catfish, and some aquarium stats would be useful: size of the tank, filtration, pH, hardness, nitrite. Cheers, Neale>

Arius seemanni dis./injury, beh.   8/1/06 Hey Guys,    I think your web site is great and I have learned a lot from you guys. Anyway I have a Arius seemanni he is about 6.5in and mostly just swims around the top of my tank. <Is a social species... should be kept in a small grouping> The other day he jumped out I was luckily there and put him back into the tank, he immediately started swimming like nothing happened. I did notice that his eyes where kind of foggy and he seemed to bump into stuff more often. <Likely "rubbed" its eyes... damaging them> But as of today 6/28 his eyes look good and I was told he had an infection.  What do you think? <I would do nothing in the way of chemical additions here... Likely will self-cure...> Also he is in full saltwater and all the water parameters are perfect.  He has no other catfish friends and I was wondering if he would be happy and school with coral catfish? <Mmm, no... Birds/catfishes of a feather/fin flock/school together... Better to have others of the same species... even if they start off considerably smaller in size> If so how many should I get? thank you for your and knowledge Joe <Bob Fenner>

Preggers Plotosid?  9/22/05 We also appear to have a very pregnant salt water catfish. her and her  mate stay together-in a 139 gal tank with community fish-we need to know if the   eggs will survive or do we need to separate her or put the eggs in a breeder   tank and about how long does it take any information you have to share we will appreciate.                     thanks <Not likely pregnant... unless very large... another (male) present to fertilize... See re Plotosus lineatus on WWM, fishbase.org... the Net period. Bob Fenner>

Marine Catfish (Plotosidae) Hi folks, Writing again for some clarification on Plotosidae lineatus.  I recently saw a number of these, approx. 2" in length at my favorite LFS.  Intrigued, I came home to check WWM for info on the animal.  I am setting up a 150gal reef system, the featured animal of which will be either Heniochus diphreutes or a dwarf angel, and many SPS.  I am wondering if a trio of Plotosidae lineatus would be suitable for this type of tank? <Should be fine. Best kept in a small number... in a good sized system.> I am concerned about them harassing and possibly using their toxins on their tankmates, and also their large size (says 1' on WWM, assuming they could easily hit 8" in captivity).  What do you think? Cheers Quinn <I say go ahead with your plans. No worries re these fish envenomizing your other noted livestock or getting too big. Bob Fenner>

Breeding Coral Cats We believe we have a pregnant coral catfish and are looking for information about their breeding habits. I've only been able to find one piece of information about this that says they build a burrow-like nest in the back of the aquarium for the laying of eggs. Do you know if there's anything special we need to provide for them? <Mmm, am unfamiliar with actual breeding accounts of plotosid in captivity. None of my ready references show any such data> We have the pair in a 10 gallon tank with a couple of live rocks to provide shelter for them, and a sand base. These catfish are about 4in. in length.     Any information you can provide will be most appreciated! <Maybe inputting Plotosus lineatus in fishbase.org, or better, hauling out to a large, college library for a literature search (please see here: http://www.wetwebmedia.com/litsrchart.htm), will give you some information. Yours might be the first recording of this event. Do keep good notes... consider writing up for the aquarium magazines. Bob Fenner> Thank you, Jan Hayter

Re: Breeding Coral Cats Dear Mr. Fenner,     Below is our previous correspondence about our pregnant coral cat. Thank you for your response. I did investigate over the Internet, but discovered no further information.     Since I last wrote, the coral cat continued to increase in size until about 10 days ago. She was so pregnant, that you could see the bulging impressions of the eggs through her skin. However, since then, she's remained pretty big but you can no longer see the bulging of the eggs through her skin.     My question is, is it possible that by not having laid her eggs, her body will absorb them back into her system? <I think this is likely. Such is known, conjectured re other species of catfishes>     This has been an interesting journey. We'll see where it leads! Thank you for sharing your expertise with us. I'll look forward to hearing from you at your convenience. <Be chatting, Bob Fenner> Sincerely,            Jan Hayter

Plotosus lineatus Dear Mr. Fenner, Because you are an expert in marine biology, I would like to know whether you have heard of "Plotosus lineatus" under the family of Plotosidae? I got a reference referring that the pineatus is the same as lineatus in the family of Plotosidae. Are they everything alike or does pineatus exist at all? Please write me back at I look forward to hearing from you. Thank you for your assistance. Sincerely, Louis Lu >> <Don't know if I ever stop smirking at such titles as expert (previous married as in "ex", and flow under pressure, as in "spurt"?), but do have some (painful) experience with the family, particularly the one species (Plotosus lineatus) that is most commonly utilized in the ornamental trade... And have posted some images, article and queries/responses folks have sent me on our site: Home Page for all's perusal. Re the "pineatus" question. No, according to FishBase: Scientific Names for Plotosus  [n=29]  Scientific Name Author Valid Name English Name  Plotosus albilabris Valenciennes, 1840 Paraplotosus albilabris Whitelipped eel catfish  Plotosus anguillaris (Bloch, 1794) Plotosus lineatus Striped eel catfish  Plotosus arab Bleeker, 1862 Plotosus lineatus Striped eel catfish  Plotosus argenteus Zietz, 1896 Neosilurus argenteus Silver tandan  Plotosus brevibarbus Bessednov, 1967 Plotosus lineatus Striped eel catfish  Plotosus canius Hamilton, 1822 Plotosus canius Gray eel-catfish  Plotosus castaneoides Bleeker, 1851 Plotosus lineatus Striped eel catfish  Plotosus castaneus Valenciennes, 1840 Plotosus lineatus Striped eel catfish  Plotosus elongatus Castelnau, 1878 Euristhmus lepturus Long-tailed catfish  Plotosus flavolineatus Whitley, 1941 Plotosus lineatus Striped eel catfish  Plotosus horridus Bleeker, 1846 Plotosus canius Gray eel-catfish  Plotosus ikapor Lesson, 1831 Plotosus lineatus Striped eel catfish  Plotosus limbatus Valenciennes, 1840 Plotosus limbatus Darkfin eel catfish  Plotosus lineatus (Thunberg, 1787) Plotosus lineatus Striped eel catfish  Plotosus lineatus Valenciennes, 1840 Plotosus lineatus Striped eel catfish  Plotosus macrocephalus Valenciennes, 1840 Cnidoglanis macrocephalus Cobbler  Plotosus macrophthalmus Bleeker, 1846 Paraplotosus albilabris Whitelipped eel catfish  Plotosus marginatus Bennett, 1830 Plotosus lineatus Striped eel catfish  Plotosus megastomus Richardson, 1845 Cnidoglanis macrocephalus Cobbler  Plotosus microceps Richardson, 1845 Euristhmus microceps  Plotosus multiradiatus Bleeker, 1846 Plotosus canius Gray eel-catfish  Plotosus nigricans Valenciennes, 1840 Plotosus limbatus Darkfin eel catfish  Plotosus nkunga Gomon & Taylor, 1982 Plotosus nkunga Stinging eel catfish  Plotosus papuensis Weber, 1910 Plotosus papuensis Papuan eel-catfish  Plotosus tandanus Mitchell, 1838 Tandanus tandanus Dewfish  Plotosus thunbergianus Lacep?e, 1803 Plotosus lineatus Striped eel catfish  Plotosus unicolor Castelnau, 1873 Tandanus bostocki Freshwater cobbler  Plotosus unicolor Valenciennes, 1840 Plotosus canius Gray eel-catfish  Plotosus vittatus  Such a species name doesn't occur in the "literature". Bob Fenner>

Fish Bob, I have become quite intrigued with your article on the web entitled, Marine  Catfishes, Family Plotosidae. I have a friend who had mentioned this  species, but was not entirely aware that a saltwater cat, this size existed. It sound like if you maintain one you should maintain two or more. Is that  true? Can you recommend any web sites that might have a photo? Do you know  what the going rate is for one of these cats and where might someone  purchase them from? Thanks much, Tom Quail >> Hmm, take a look at the wealth of reference on ICLARM's FishBase (www.fishbase.com) for pix. Oh, and thank you for prompting me to look on our site Home Page and place my best image on the Marine Catfishes article there as well... And yes to the more the merrier... And I've seen Plotosus lineatus selling for ten to twenty dollars each recently.... Your dealer, or an on-line etailer like ffexpress ought to be able to order/get them for you. Be chatting,
Bob Fenner



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