Trachycorystes trachycorystes
(Valenciennes, 1840) |
o good they named it twice! well I don't think so as this is one
of the most aggresive catfish around in the hobby and definately
not suited to your average community tank, although It is certainly
very striking looking in its all-black livery. There is another
type which has a more brown body colouration and may turn out
to be a seperate species.
A fellow aquarist has told me about a friend
who kept one, and stated that it was very aggressive, and you
had to watch if you put your hands in the tank as it was prone
to attacking the hand that feeds it!. It is very strange indeed
as the Auchenipteridae family on the whole are not known for their
aggressive behavior.
There are three other Trachycorystes
species, T. cratensis from the Rio Granjeiro in
Brazil, T. obscurus from the Rio Essequibo basin in Guyana,
and T. porosus. Our factsheet of the month T. trachycorystes
is the only member of this genus to be exported, but they are
still not a common site in the aquarium shops.
The mouth you have to watch!
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It is reported (watkins, et al) that this
catfish is an important food fish in the Iwokrama Forest in Guyana
but this species may be T. obscurus (Rio Essequibo basin)
alongside the larger species of the Pseudoplatystoma genus.
This is a catfish for the more experienced
keeper who knows what they are getting for their pound of flesh!.
Provide shelter in the aquarium such as driftwood as it will hide
there during the day and venture out at night for food. It may
come out in the open during the day if it is relaxed and confident
enough.
The tank length should be at least 4" 6" ft (135cm)
or over at least, and the width would need to be 18" (45cm)
for an adult to turn around comfortably. Substrate is not important,
using either smooth gravel or sand.
Head is broad and depressed, the width of
the cleithra almost twice the depth. The bones of the head are naked
(without a covering skin) and fused, forming a solid, heavy, very
rugose casque; there is a small oval fontanel. The mouth is wide,
horizontal, and the lower jaw extends beyond the upper and a band
of small teeth is present in each jaw, but there are none on the
vomer and palatines. The dorsal and pectoral fin spines are strong,
pungent, the dorsal fin spine with teeth
along its anterior edge only, the longer, stronger pectoral fin
spines with teeth along both edges. The adipose fin is very small,
and the anal fin is of moderate length, with about 20 rays. The
ventral fins have 9 or 10 rays, and the caudal fin is emarginate
to slightly forked.
Black all over, some species have a white
underbelly. Fin edges may have a white
fringe to them.
Not to be trusted when growing into adulthood
as it will quickly kill any smaller inhabitants of the tank. May
be able to keep with large Cichlids but basically a fish to keep
on its own.
Like all members of this family, T. trachycorystes
practices oviducal fertilization. There
are no known reported aquarium spawning's of this catfish but can
be sexed due to the thickening of the anterior of the anal fin,
as is the norm in this family, akin to the anal fins of the males
of the Goodiae family of livebearers. The females store the sperm
to fertilize their eggs.
| Sexual
Differences |
Adult males possess a
thickening of their anal fins akin to the anal fins of the
males of the Goodiae family of livebearers. The females genital
pore is enlarged and recessed into her abdomen.
|
| Feeding |
A predator but will accept worm foods, frozen
shrimp and bloodworm, chunks of frozen fish, tablet and pellet foods.
| Glossary
of Terms |
Dorsal fin:The
primary rayed fin(s) on top of the body.
Pectoral fin: The paired fins after head
and before anal fin.
Adipose fin: Fleshy finlike projection
without rays, behind the rayed dorsal fin.
Caudal fin: The tail.
Cleithra: A flattened pointed posterior
extension of the pectoral girdle.
Casque: Shaped like a helmet.
Fontanel: The space(s) between the bones
on top of the skull covered by skin.
Vomer: The anterior bone in the mid-line
of the roof of the mouth.
Palatines: The teeth present on the palatine
bone which lies laterally in the roof of the mouth.
Emarginate: Concave; used to describe the
posterior border of a caudal fin which is inwardly curved;
a caudal fin with a slightly concave margin
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| Etymology |
Trachycorystes:
Greek, trachys,
-eia, -ys = rough + Greek, chorystes, -ou = a soldier with
helmet
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| References |
Watkins, Graham;
Saul Bill; Holm, Erling; Watson, Cynthia; Arjoon, Deokie;
Bicknell Jake and the North Rupununi District Development
Board. The Fish Fauna
of the Iwokrama Forest. 32 p.
Ferraris, Dr. C.J. Jr., Catfish in the Aquarium.
An introduction to Catfish Keeping and the Diversity of Catfish
Forms and Behavior. Tetra Press Publication. 199 p.
Burgess, W.E. 1989
An atlas of freshwater and marine catfishes. A preliminary
survey of the Siluriformes. T.F.H. Publications, Inc., Neptune
City, New Jersey (USA). 784 p.
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| Photo
Credits |
Top © amiidae @ 
Bottom: © Allan James @ 
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