oncinus ( Schomburgk, 1841)
ur first factsheet of 2005 takes us back
to the South American continent and to a member of the Auchenipteridae
family which was discovered
164 years ago in Brazil by R. H. Schomburgk in 1841, and this
beautiful catfish has had a checkered history ever since.
Schomburgk named it Arius oncinus
after the species name of the Jaguar Cat (Panthera onca)
due to its body pattern resembling this cat of the South American
rain forests. In 1940, Fowler described a new species from Peru,
morrowi, and placed it in the Doradidae
family even although it did not have the bony scutes that this
family possess, but it had the spiny humeral process of this family.
Onwards to 1978 and an article with illustrations appeared in
the TFH magazine by Martin Brittan and it alerted the Ichthyologist,
Mees, who subsequently published a paper on this catfish. Mees
noted that the fish in the article, which was mooted as a Centromochlus
species, looked very like the original description by Schomburgk.
He obtained specimens form Brittan and also the type specimen
of L. morrowi and concluded, incorrectly, that they were
one and the same fish and placed it in the Doradidae family. It
was not until 1994 that these two species were considered as separate
and they were placed in the Auchenipteridae family.
Stamp depicting the original colour
plate of Liosomadoras
This is indeed a beautifully
marked catfish but in the aquarium you may not see too much of
its beauty as it can be crepuscular in nature and will need hiding
places to make it feel more secure and happy in its surroundings.
Above is Liosomadorus morrowi, the Black Jaguar Catfish.
I was given this fish by a friend who had bought it as a Jaguar
Cat and did not know what it was. You may find the common name of
the Black Jaguar Catfish misleading from this picture, but this
photo was taken on the show bench and it had lost the dark markings
that you will find when it is settled in your tank set up. The parameters
given for L.oncinus will be the same for L morrowi.
Body short and compact
with a compressed caudal peduncle. Head, large and broad, its width
at the clavicles greater than its length. The long humeral extension
has small spines and the barbels are thin and filamentous without
branches. Dorsal spine has teeth on anterior and posterior edges.
Pectoral spines have outer and inner margins strongly denticulated.
Adipose fin is the same length as the anal fin, ventral fins short
and positioned nearer the anal fin than the pectoral fin base. Caudal
Yellow blotches on a brown body bordered on
each side of the distinct lateral line. Fins
Can be kept in a community tank but may eat
very small fish at night such as the fry of livebearers, but basically
a good addition to the larger tank set up.
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.
Will take most prepared foods such as frozen
bloodworm, tablet and flake food. Better to feed at night after
lights out, but once settled in tank will forage for food in low
Finley, Lee, Catfish
Corner, The Jaguar Catfish, Tropical Fish Hobbyist; Aug.1997
From the Greek leios, meaning smooth; soma; meaning body and
Doras (a genus of doradid catfishes); in reference to the
lack of bony plates on the body (when the genus was described
as a doradid).
oncinus: Named after the Jaguar
cat, Panthera onca, because of its markings.
Burgess, W.E., 1989 An Atlas of Freshwater and
Marine catfishes: a preliminary survey of the Siluriformes. T.F.H.
Publications, Neptune City, New Jersey
Ian Fuller @
Julian Dignall @