The Elusive Jaguar
Liosomodoras oncinus
by Michele Romeo
First published in the Monthly Bulletin of the Hamilton and District Aquarium Society
Aquarticles
Named for the rare Jaguar Cat, Panthera onca, of the South American Rain
forests and just as elusive and beautiful, Liosomodoras oncinus is a rarely seen
catfish from Peru. Easily one of the most beautiful of all catfish, it has appeared,
although infrequently, as a contaminant in shipments from Peru. Juvenile specimens are
even more striking than adults, their patterns being a brighter yellow and lighter brown.
The genus Liosomodoras contains two species, L. oncinus, originally
described in 1841 by Schomburg from the Rio Padauiri and L. morrowi, described in
1940 by Fowler. To date, there is still a question as to whether this genus belongs to the
family Doradidae or Auchenipteridae. There are those who believe that
this genus is an intermediate form, which possesses morphological characteristics of both
families. For example; while having a spiny humeral process, characteristic of Doradids,
they lack the lateral plates found in the species of the genus Auchenipteridae.
However, Liosomodoras also differ from this family by having a very broad, low
head.
The Jaguar Cat is typically nocturnal, hiding by day and actively feeding by night. You
can observe the activity and feeding strategies of this fish by substituting red lights
for fluorescent bulbs. While some catfish exist in schools, such as Corydoras
sp., others are active midwater schoolers such as Pangasius sp. The Jaguar
prefers to "cruise" the bottom at night alone, in search of food. When keeping
more than one individual, provide a large tank with plenty of shelter, as they are
extremely territorial. Pieces of PVC pipe and driftwood work extremely well. If the fish
do battle over territory, you will hear the fish produce sounds by a process known as
stridulation. This is a process where the spines of the pectoral fins are rotated at the
base. this results in a sound similar to a tuba or foghorn. Many other species of Doradids
and Auchenipterids as well as Synodontids emit similar sounds. Imagine the symphony I hear
at night as my 200 gallon tank contains all three types of catfish!
From my experience working in the hobby, I've had the privilege of seeing the
occasional "oddball" fish many times. Whenever we received a bag of Jaguar cats,
at least ninety percent of the fish were dead on arrival. They were covered in fungus, due
to the wounds caused by the territorial nature of the fish. Remember, fungus is very
opportunistic when it comes to fresh wounds. Picture twenty-five large Jaguar Cats trying
to shred each other in a large plastic bag! Another observation I made from my own fish is
that they do not like temperatures above 76 F. At higher temperatures the fish hovered in
midwater and stopped eating. With water parameters of pH 6.8 and no ammonia or nitrite, I
could only conclude, that the Jaguar Cat preferred cooler temperatures. I have also
observed this to be the case with Corydoras, namely: C panda, C. barbatus,
and C. caudimaculatus.
As with most catfish, water quality is a very important if not the most important
parameter for long term, captive maintenance. The Jaguar cat prefers soft, slightly acid
water with a pH of 6.4 to 6.8. waste build-up should be kept to a minimum, with. weekly
25%' water changes. I recommend an aquarium that has been established for at least eight
months, as these fish do not tolerate excessive nitrogenous waste. I never recommend
cycling a tank with any catfish! As far as food goes, the Jaguar Cat is not particularly
fussy. Frozen bloodworms are the favourite, but TetraBits and spirulina flake are also
readily taken. The Jaguar cat can be housed with medium to large fish as well as smaller
tetras!
As to compatibility: my Jaguars are housed in a 110 gallon tank with numerous Corydoras,
Tatia sp. and other smaller Auchenipterids. They only become quarrelsome when
another fish tries to set up shop in their PVC pipe. Otherwise, given plenty of room and
shelter, this is a very peaceful species. I also would not recommend the more aggressive
species of cichlids as tankmates because the Jaguars are smooth skinned and lack the
proper defences against repeated attacks. To date there are no known reports of breeding
this beautiful species. Males and females are easily distinguished. The male's organ can
be seen at the anterior edge of its anal fin and the female is shorter in body length and
heavier in the abdomen. Hopefully, enough fish can be collected and we will hear about
spawning reports in the future.
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