Catfish of the Month Right Arrow March 2007 • Article © Marc Stabel, uploaded February 28, 2007



Fisher's Woodcat - Trachelyopterus fisheri   (Eigenmann, 1916)

After an all too short stay with me in Scotland, I'm delighted to feature a catfish of the month article from Dutch woodcat fan, Marc Stabel. During his whirlwind tour of central Scotland's castles, lochs and fish stores, Marc also agreed to write a catfish of the month article for us, and so here it is.

Fisher's Woodcat, Trachelyopterus fisheri, is not a very common species. So I was very pleased when I encountered three specimens in a shop in Amersfoort, here in the Netherlands. At first I purchased a pair together with one Trachycorystes trachycorystes, but due to compatibility problems I had to return the latter and therefore came back home with T. fisheri number three, which was a female.

There are few problems with regard to discerning gender in this species. Males have a genital papilla, thickened maxillary barbels, spawning tubercles on the barbels and on top of the head. The most striking masculine feature is, however, a curved and enlarged dorsal spine which can also be moved up and forward. Their nape is bent upwards, as can be seen in Tetranematichthys and Ageneiosus spp. Females grow (much) larger and, at least according to reference books, should display a plainer colour pattern, but I don't agree on that. Although my females are about 25cm at the present time, they still have a very nice sort of blotched pattern which make them quite invisible in a tank full of bogwood.

T. fisheri is the largest Trachelyopterus species discovered to date, yet it is amazing how gentle this fish is. It seems to glide through the water and never displays the hastiness which is so typical for other members of its genus. As a matter of fact - although being an amateur - I think this species comes very close to Ageneiosus with regard to behaviour and looks. Take for instance the nape and the enlarged dorsal spine of male T. fisheri. No other described Trachelyopterus species have these features to this extent. Also they like to swim somewhat head-up, another feature they have in common. Of course, there are differences as well. The mottled wood-like pattern is not apparent on any known Ageneiosus (but it is on Tetranematichthys!), the structure of the mouth is different; terminal in T. fisheri, inferior in ageneiosids and I won't even mention the scientific differences, by which I mean internal things, fin ray counts etc. For it should be clear that there are scientific reasons that these fish do not belong to the same genus.

This woodcat is indeed a social fish. Some weeks after I had bought them one female became a little grumpy towards the other two. This lasted for several weeks and consisted of grunting and trying to push them away. After that period I have not heard or seen this behaviour repeated. They will happily share their hiding spots with other fishes. Yesterday I introduced some new woodcats in the tank, which for obvious reasons wanted to find some dark place. Whereas the Jaguar Cats, Liosomadoras oncinus put up a fight to defend "their" piece of wood, the fisheris didn't mind their space becoming very crowded all of a sudden.

These fish have a voracious appetite and can look like barrels at times, especially the females. So, when kept with other fishes one must see to it that there is enough food for every fish. That implies that the water conditions and filteration should be taken care of properly. In my 720 litres tank (200 x 60 x 60 cm), I replace a quarter of the contents every month. Two Eheims (2228 and 2028 Pro series) take care of the dirt and are cleaned every month as well, but never at the same time as the water replacements. If kept under fair conditions, these fish are very hardy and hardly liable to diseases.

Normally these woodcats will show up when being fed, except maybe when you have to do some things in the tank (rearranging, cleaning) shortly before. However, they are certainly less visible when compared to when I first got them. Perhaps the old woodcat rule applies: the larger and older they get, the less you get to see them. I keep mine together with a bunch of other Auchenipterids and twelve Exodon paradoxus, which are not only beautiful, but also useful as dither fish. At the end of this article I state that Auchenipterids in general shouldn't be kept with aggressive fishes, so you might think my combination is strange, to say the least. However, the characins do not harass my catfishes. For some reason or another, they apparently know that the catfishes do not have scales. They may chase the cats when they are swimming around but actually never actually bite.

T. fisheri has already been bred in captivity and I wouldn't mind them breeding here as well. I witnessed some activity in this regard, but the male was rather clumsy in trying to clasp his female, which swam off like nothing had happened. Still I have some hope it will actually happen one day and if so you will be the first to know. For someone who is planning to buy this species and to end this CotM article, here are - in short - a few essentials:

  • These fish grow to 28cm, see to it that you can provide them with enough room. I think a tank of 500 litres is minimum
  • Give them places to hide and, at the same time, free swimming space
  • Do not keep these gentle fish together with "aggressive" species. They are quite defenseless against (for instance) cichlids or other fishes that may harass them during the day when they are resting and thus become very vulnerable then. Even a fin nipping krib may be considered aggressive in this respect
  • Also do not keep them together with small species, smaller fish may be eaten "by accident"

  • Copyright information for the images used in this article can be found on the species' full Cat-eLog page.

    Jump to next section Cat-eLog Data Sheet
    Scientific NameTrachelyopterus fisheri  (Eigenmann, 1916)
    Common NameFisher's Woodcat
    Type LocalityColombia, Sucio River
    Synonym(s)Parauchenipterus fisheri, Trachycorystes fisheri
    Pronunciationfish err eye
    EtymologyTrachelyopterus: From the Greek, trachelos, meaning neck and pteron, meaning fin; in reference to the long cranial shield, which gives the appearance that the dorsal fin originates at the neck region. The specific epithet is named after the American entrepreneur Carl Graham Fisher.
    Jump to next section Species Information
    Size 280mm or 11" SL. Find near, nearer or same sized spp.
    IdentificationThis is by far the most slender of all Trachelyopterus species. Another feature that gives its identity away is the terminal mouth, whereas other Trachelyopterus species have a slightly superior mouth (see also General notes).
    SexingMales have a genital papilla, thickened maxillary barbels, spawning tubercles on the barbels and on top of the head and a curved, enlarged dorsal spine which can be moved up and forward. Also their nape is bent upwards, as can be seen in Tetranematichthys and Ageneiosus spp. Females grow larger and display a plainer colour pattern.
    General RemarksIn terms of general captive behaviour, this species doesn't resemble its congeners, but is more easily compared to the larger Auchenipterichthys and smaller ageneiosids. It's a very gentle species that glides through the water and never displays the hastiness which is so typical for other members of its genus. Moreover, the nape and the enlarged dorsal spine make it look more like an Ageneiosus or a Tetranematichthys.
    Jump to next section Habitat Information
    DistributionColombia, Sucio River
    Colombia Caribbean Rivers, Atrato, Sucio (click on these areas to find other species found there)
    Show it on a map (Click the map-icon to show/hide map of species distribution)
    pH6.0 - 7.0
    Temperature22.0-32.0°C or 71.6-89.6°F (Show species within this range)
    Other ParametersGenerally undemanding.
    Jump to next section Husbandry Information
    FeedingThis species is not shy and can regularly be seen during the day, especially when being fed. All prepared and frozen foods are taken. Like all Auchenipterids - being surface feeders - they are particularly fond of insects and their larvae.
    FurnitureLarge pieces of driftwood as hiding places. See to it that there is also plenty of swimming space. The aquarium shouldn't be too brightly lit.
    CompatibilityDespite their size these fish are very gentle, social and peaceful. Smaller fish may however be eaten, due to the fact that they rest at nights while the fisheris are on the move.
    Suggested TankmatesNon-agressive fish and fishes that aren't too small.
    BreedingHas been recorded (see Reference notes below). Like other Auchenipterids these fish have internal fertilization. The bodies are wrapped around each other and to stay in position the male uses its barbels, dorsal spine and spawning tubercles. The actual mating lasts for about 30 seconds or less. Four weeks later the female lays her eggs. The parents will neither look after their eggs, nor eat them.
    Jump to next section Further Information
    ReferencesAnn. Carnegie Mus.v. 10 (nos. 1-2) - pp82
    TFH August 1982, pages 84-89, Burgess and Azuma: The first spawning of the woodcat, Trachycorystes insignis [sic]
    The same pictures and a very short summary of the article can be found in An Atlas of Marine and Freshwater Catfishes (1989), pages 586-589, Burgess. In this book the fish is named Parauchenipterus fisheri, which was the correct name at the time.
    Registered Keepers(1) Osiris, (2) Junttis (k: 2), (3) Bijn (k: 4), (4) arapaimag, (5) yadayada, (6) Ghenriques, (7) JohnRayNg (p: 2), (8) Altifrons, (9) pokemonrange (k: 3), who also notes: "I think Trachelyopterus fisheri is a kind of catfish which isi special. They are not afraid to light and they would swim in the front part of the tank when they see u. It is amazing that a catfish would love to chase your moving finger. sorry for poor english :(", (10) CruiserCountry, (11) Marine590622, (12) firman catfish, (13) Domaku (p: 2), (14) cory-ap2, (15) Gulper, (16) daniel60 (k: 4).

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    Breeding Reports(1) pokemonrange (b: 49).
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    Last Update2012 Jan 31 13:19 (species record created: 2007 Feb 28 20:57)

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