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 Lacepède, 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