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.
Trachycorystes
trachycorystes
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.
Trachycorystes
trachycorystes
- the mouth you have to watch!
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.
South America:
Brazil, Venezuela. Amazon basin
and Orinoco River subbasin.
Size
35.0cm (14ins)
Temp.
23-27°c (73-81°f)
p.H.
6.5-7.0.
Characteristics
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.
Colouration
Black all over, some species
have a white underbelly. Fin
edges may have a white fringe to them.
Aquarium
Care & Compatibility
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.
Reproduction
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.
Diet
A predator but will accept
worm foods, frozen shrimp and bloodworm, chunks of
frozen fish, tablet and pellet foods.
Glossary
of Terms
Adipose
fin: Fleshy finlike projection without rays,
behind the rayed dorsal fin. Dorsal fin:The primary rayed fin(s)
on top of the body. Casque:Shaped like
a helmet. Caudal fin: The tail. Cleithra: A flattened pointed posterior
extension of the pectoral girdle. Emarginate: Concave; used to describe
the posterior border of a caudal fin which is inwardly
curved; a caudal fin with a slightly concave margin.
Fontanel:The space(s)
between the bones on top of the skull covered by skin. Palatines:The teeth
present on the palatine bone which lies laterally in
the roof of the mouth. Pectoral fin: The paired fins after
head and before anal fin. Vomer:The anterior
bone in the mid-line of the roof of the mouth.
Etymology
Trachycorystes:Greek, trachys, -eia,
-ys = rough + Greek, chorystes, -ou = a soldier with
helmet. trachycorystes:
trachys, rough; corystes, helmeted, referring to rugose
cranial shield.
References
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. 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. 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.
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