© Copyright text and photos, Datz,
published here with permission.
hich observer at first sight doesn't become enthusiastic? A
catfish, which in appearance and behaviour and eating, even
in its swimming movements has something similar with sharks.
And with it socialization is also possible.
 Some
aquarists know this phenomenon: The keeping of a certain fish
species binds one in such a way that one turns to it again after
many years of occupation with other ornamental fish.
The catfish species described here we
already had kept in the middle of the 1980s, and after approximately
two decades we returned to it again to its keeping, whereby
the procurement of one specimen brought us together and led
to an active exchange of experiences.
C. macropterus, doing
laps of the aquarium in expectation of food.
Species description
The genus Calophysus belongs to the large family of
the Pimelodidae and is monotypical, (consists only of the one
species). The German description “Gefleckter Silberantennenwels”
(meaning “spotted silver-coloured Pimelodus”) describes
the colouring of this species which is far spread in the northern
parts of South America and particularly in the Amazon basin.
On its long stretched silver-grey body it exhibits a multiplicity
of irregular dark points. By means of this mottling there can
obviously be different habitat variants that are about. Above
all, the bluish resplendent gloss intensifies, starting from
a length of 30 centimetres making this a true eye catcher
In its body form and patterning C.
macropterus reminds us of two further catfish species of
South America: Aguarunichthys
torosus (German: Stierantennenwels), which is however
spotted up to the underneath of the belly, and the even more
rarely introduced Platynematichthys
notatus, whose impressive extended dorsal fin ray makes
it unmistakable. Also C. macropterus is not often seen
in the trade, however it is now and is offered by specialist
dealers, who specialise in the import of predatory species.
Particularly young animals are to be had with approximately
40 euro, which is comparatively low priced.
Keeping
When stressed this species is quite oxygen needy, and it indicates
this by an increased respiration rate, so moved specimens need
rather a long time until they have acclimatised themselves,
therefore the keeper should pay attention to sufficient ventilation.
Besides this, it is durable, and with good filtering a temperature
of around 24 degrees Celsius and otherwise "normal"
water parameters, it is easily kept.
 In
its natural habitat C. macropterus will get to a maximum
length of 60 centimetres, in the aquarium it reaches 40 to 50
centimetres. Since it is no ambush predator but a more active
species, tanks that are to be used should, if at all possible,
be not less than two meters in length and a minimum depth of
70, or better, 80 centimetres.
This catfish feels well if it has a sufficient
swimming area left to it. In the rear of the aquarium, well
secured stone structures or durable solitary plants should be
present and roots or large stones as resting places, then a
hiding place, into which the animal can retire itself completely,
is not necessary.
Calophysus macropterus
adult in profile - with its barbles this catfish can smell excellently.
Aquarium observations
C. macropterus proves in the aquarium that it can be
relatively peaceful. Generally one can find it at its favourite
place, to which at the same time also means that you can use this
as an observation post, particularly since the catfish leans on
its ventral fins and erects the upper part of its body. In nature
predominantly with entrance of dawn they are active. Aquarium
specimen are also out during the day in this way. Separately kept
they seem to do quite well.
 Referring
to occasions as with feeding, in addition during vibration, this
catfish is very mobile and speedy. As soon as the keeper approaches
the aquarium, C. macropterus notices him or here, because
even over a certain distance it begins to relate to its keeper
by means of its very long upper barbles. The
hungrier it is the jerkier and in addition livelier it becomes
and shows this by swimming up and down the front glass. As soon
as food was given the predator is in action and looks for it.
At this sight of this visitors automatically draw parallels to
the swimming movements with sharks, particularly if C. macropterus
also puts up the dorsal fin completely, its slim elegant body
reminds them of these large sea predators. First slowly, then
getting faster and as soon as the food morsel was located, snapping
it fast, showing its hunting behaviour.
The high-sensitive barbles leads
the animal to the piece of trout lying on the ground.
Even for the viewer it is impressive: First
finding the prey in principle takes place not by means of visual
contact, but owing to the forward placed barbles it guides the
animal even with weak smelling traces, and as also in nature in
cloudy water, still leading to the food.
The species is not choosey with the selection
of its food and besides live foods such as earth worms it also
gladly takes shrimps or fish filets, even food sticks or Forelli
pellets are eaten. In nature these flexible predators are even
predominantly nourishing themselves on carrion, therefore comes
the English description of "Vulture Catfish". So it
is not surprising that the muzzle of C. macropterus with
its strong jaws and the very special teeth is able to rip out,
even with very large food portions, unproblematic bite-sized pieces.
If the animal is full, it rests on its favourite place, but even
this phase is interrupted in irregular fashion and swims in one
or two rounds through the tank, before it rests itself back there
again . As well as we never see our specimen digging, so plants
will not be damaged, however they should be firmly fixed in the
bottom, because otherwise with the occasionally hectic movements
of the catfish, they will be uprooted.
 C.
macropterus can be associated with congeners. For this purpose
one lets them grow up together, best with two or three young animals.
They are predatory catfish with fast growth,
but although somewhat dependent on the aquarium size too, 10 to
15 centimetres long specimens grow more than the double of there
own length in the first year of there keeping.
About five years old, specimen
of 45 cm in length and a weight of over 1 kg, resting on its favourite
place.
 Among
one another this species even looks for body contact: Two young
animals of same size, which we socialised with one another, often
would lie together, until one starts abruptly and after a short
excursion in the tank associates itself again with the other one.
Every now and then they do some rounds together and then push
themselves mutually together. Possibly the social behaviour shown
here is already conditioned as sex specific. There are still no
consolidated findings to possibly present any sexual differences,
probably however with adult animals the males are slimmer.
Altogether C. macropterus is somewhat
more active when socialising with congeners than during single
keeping.
Young specimen of 13 cm in length,
whose colouring is brighter than with older animals.
Disputes among themselves are to be observed
rather rarely. They bite obviously only if the size differences
are noticeable or one tries to bring together an older specimen
after longer single keeping with a possibly younger animal, then
the smaller species can be seriously hurt and regarded even as
food. If one adds other fish species which fit into the predatory
pattern of the catfish, and this counts for example all livebearers
from the Poeciliidae family, in addition Cyprinidae like the gold
fish (Carassius auratus auratus), then C. macropterus
immediately begins the pursuit. It skillfully understands to press
its victim under usage of the forward spread and thereby making
a larger radius of action possible with its upper barbels for
a long time until biting is possible.
 If
the catfish cannot devour the prey fish at one time it will, and
also here the parallels to the sea predator are unmistakable,
be made disabled by a bite in the tail fin or a separation of
the complete tail. Attracted by the smell and the death fight
of the prey the possible species companions also take part, then
the rest of the prey is fed by all in a true devour orgy. The
first attack is already done so fast that an intervention of the
keeper usually comes too late.
The upper barbles of Calophysus
macropterus are very long and reach back to the end of the
caudal fin.
 Such
losses are the reason this species has suffered such a reputation,
however they can be avoided in the tank if sufficient food is
always given, but understanding automatically that this happens
with the keeping of predatory species.
In all other respects associated fish are
to be selected carefully. Central and South American cichlids
and above all the well fortified species are possible, in addition
large L-catfish and with appropriate tank sized fresh water rays
of the genus Potamotrygon. Opposite them, C. macropterus
behaves completely peacefully, even in the long term.
C. macropterus can be
associated well with larger cichlids like here in the background
with Oscars (Astronotus ocellatus).
 Conclusion:
C. macropterus is a really impressive and quite active
species. For many catfish lovers it is manageable and at a just
acceptable final length, and in addition contrary to some other
predatory species, at all ages a complete beauty, making it an
absolute recommendation.
When reasonable planning even socialization
is possible. Under aquaristic aspects this interesting catfish
to this day is undervalued and could be more frequently seen in
big home aquariums to convince astonished visitors of its attractiveness.
An eye catcher in the big aquarium.
With this specimen the bluish colouring is particularly strongly
pronounced.
 This
article was published in April 2008 in the German publication:
"Die Aquarien
und Terrarienzeitschrift" (Datz) 61 (4): 16-18.
Our thanks apply here for the Datz editorship
and their editor-in-chief, Rainer Stawikowski, who gave us kind
permission to publish this article on Scotcat.
© Copyright text and photos, Datz,
published here with permission.
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