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Tank Busting Catfish Part One: The Debate Continues..
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Chris Ralph |

ollowing on from my learned colleague and fellow catfish
enthusiast Daphne Layley’s article in Practical Fishkeeping
February 2005, I felt compelled to pen this article in support
of what Daf had written. Daf and I have shared many conversations
over our 20 plus year friendship which dates back to our
days spent serving as committee members of the sadly now
defunct Catfish Association of Great Britain. We lost contact
for a while but in the last couple of years through our
mutual interest and passion for all things catfish, Daf
has taken up membership and involvement with the committee
of the now recently re-named Southern Counties Catfish Rescue
Society (SCCRS), and our conversations have continued to
flourish as a result. We have discussed at great length
the good and bad points involved with the keeping of large
catfish, bearing in mind that over the years both Daf and
I have kept a number of large catfish with the needs of
the fish being at the forefront of our minds. As many of
you are probably aware I am fortunate enough to have a couple
of tropical ponds within the confines of my fish house.
Over the many years that I have been keeping fish I have
been called upon to rescue a few less fortunate catfish,
which have been able to live out their final days in the
surroundings of a 12’ x 30” x 48” pond
(30” being floor to top of the pond depth), an environment
which is far removed from their natural habitat, but nonetheless
better than that of a 48” aquarium.
Quite what the answer is to the debate of responsible ownership
of a fish that can easily attain say 24”, and there
are a number of species more than capable of achieving this
I do not know. I have personally kept a number of large
doradids the biggest of which, an Oxydoras niger (Pseudodoras
niger) was 42” in length, I think that you must agree
a truly magnificent catfish, but one that most fishkeepers
would not be able to accommodate due to space and or money.
I must say that I have been very fortunate to be able to
have kept a number of large catfish live to maturity and
beyond. Many years ago some other friends and I discussed
the idea of people having a licence to keep all big catfish
and any other large fish for that matter. Would it be a
licence that the responsible person would have to pay for
and produce at a retailer after their facilities had been
inspected by another responsible person? How would the facilities
be policed in order to ensure that the accommodation was
still suitable for the fish being kept some months or even
years down the line? How would you stop the fish being given
to someone else when for whatever reason its original owner
had to part company with it? The list of questions and the
debate is almost endless, the answer lies out there somewhere;
although how much longer can the hobby and the trade who
potentially are at the brunt of it all continue to allow
these tank busting fish to be imported?
On a personal level I was very fortunate to visit Peru with
a number of friends from the Catfish Study Group (UK) in
July 2000. During my two and a bit week stay I was not only
to be able to visit a number of different habitats in order
to collect fish and enjoy the company of some really good
friends, but I was able to experience first hand how our
truly delightful hobby impacts upon the local population
of people in Peru. I was able to meet a number of exporters
as well as some of the people involved with the collection
of our fish. I remember being told think of any species
of South American fish that could be found in the rivers
of Peru, and our contacts at the exporters could take us
there (if only we had the time!) or obtain the fish in question
for us. I know for a fact that if the organised hobbyists
along with the trade said “Right we will not import
any tank busting fish in the future” that because
of how things work abroad and the fact that many livelihoods
depend upon the tropical fish industry, that we would still
see some of the unwanted species being exported, but possibly
under the guise of a new name or indeed new species in order
to attract orders. You would also see unwanted species being
shipped to make up the orders as substitutes for fish that
were not available at the time of ordering. In truth there
is a lot of education required both at hobbyist level and
at trade and exporter level. Quite how we achieve this I
do not know. I must stress that I am not here trying to
give the honest trade bad press, as I am merely expressing
my thoughts out load so as to speak. I have a number of
very good friends involved in both the retail side of our
hobby and also within the wholesale trade, and I know how
hard they work to get things right and make their businesses
work. There are unfortunately in every walk of life those
people who do not care or give a damn so long as they either
make a living selling these fish, or those that keep the
fish that they want to in less than ideal conditions, to
these people I do not apologise for my thoughts and comments.
To further back up the information given in Daphne’s
article I thought that I would put together some information
on some of the larger South American catfish, some of which
I have had the true pleasure of owning or perhaps looking
after is more appropriate! Obviously I would be one of the
first to obtain a licence in the future in order to keep
some of my favourite larger catfish, although I have to
say that personally these fish should remain in their natural
habitat! This fact is borne out after seeing the body of
a Red tailed catfish in the fish market in Iquitos, Peru,
which would have been in excess of 72” long had its
head still been attached to its body, I rest my case! As
promised please find the following information on a few
of my favourite tank busting catfish.
Oxydoras niger (Valenciennes,
1821)
Common Names: Mother of Snails Catfish,
Ripsaw Catfish & Black Doradid
Family: Doradidae
Synonyms: Doras niger, Doras humboldti,
Pseudodoras niger, Corydoras edentatus, Rhinodoras niger,
Rhinodoras prionomus, Rhinodoras teffeanus.
Water conditions: pH 6.0 to 7.8 with
up to 25 dGH hardness
Origin: Amazon region, Peru, Brazil,
Rio Purus, Rio Sao Francisco.
Temperature: 70 – 75 ºF
Size: In excess of 36” (one of
mine was 42” when it died)
Sexing: There are no known external sexual
differences. There are however some thoughts and suggestions
that there may be some differences in the shape of the
bony plates which extend from the head to the edge of
the pectoral fins. It has been suggested that the male
has a more pointed plate, whilst the female has a more
rounded plate. There is no scientific evidence that is
available to support this observation.
Feeding: Readily accepts all manner of
prepared foods. Stinking Sinking Catfish Pellets are high
on the list, alongside floating pellets and sticks, as
well as frozen bloodworm, chopped mussel and earthworms.
Breeding: As yet unknown.
Compatibility: A real “Tank buster”
if ever there was one. Quite a character obviously suited
to large accommodation especially if keeping a number
of fish together. Peaceful towards other fish and members
of its own kind.
Suggested Tankmates: Other doradids such
as Agamyxis pectinifrons (Spotted Dora), Platydoras
costatus (Striped Dora), Oscars and any other fish
of a compatible size.
Furniture: Large pieces of bogwood and
clean plastic drainpipe of suitable diameter for them
to hide under. Ideally heater guards should be provided
in order for the fish not to burn themselves.
Comments: The Mother of Snails Catfish
is not a very commonly seen doradid, although if you have
kept one then it is one that you will not forget in a
hurry due to the size that they can grow to These catfish
are usually offered for sale as juvenile specimens at
around 4” in length. To the unsuspecting aquarist
they have probably taken on more than they bargained for!
This said if you are a genuine enthusiast you would already
know a bit about these fish and their requirements prior
to their purchase. The colour of these fish is basically
dark brown to black, hence the name Black Doradid. If
you own one of these catfish you will know that feeding
time can be a rather wet experience, even with tight fitting
cover glasses, or in my case an open topped pond! I have
lost count of the number of soakings that I have had over
the years! I purchased my first Mother of Snails Catfish
about twenty years or so ago. The first one that I owned
was around 10” long SL (25cm) and very rapidly outgrew
a 72” x 18”x 18” aquarium. I eventually
purchased a larger aquarium 72” x 24” x 36”
and went on to keep this fish for a number of years. When
the fish died from a bacterial infection it was almost
28” in length, and would have required an even larger
aquarium before too long. This was really the main reason
behind the construction of the Tropical Pond, although
at present I am not keeping any large catfish. The Mother
of Snails Catfish belongs to the Family Doradidae, all
of which originate from various locations throughout South
America. Occasionally amongst imports of Oxydoras
niger there are the odd slightly different specimens
which tend to have black coloured fins and a grey coloured
body, which are Pseudodoras holdeni. One of the
main characteristics of the doradids is the presence of
thorn like projections along the side of the body, which
are known as scutes. These scutes are very sharp, so care
should be taken when moving these fish. Sometimes literature
refers to the doradids as “Talking Catfish”
due to the fact that they can be heard to make audible
noises, almost as if they are speaking to one another.
There have been no records of these catfish having been
successfully bred under aquarium conditions yet, which
is probably just as well!
Pterodoras granulosus
(Valenciennes, 1811)
Common Name: Common Bacu
Family: Doradidae
Synonyms: Doras granulosus, Doras
maculates, Doras murica, Doras murices
Water: pH 6.5 to 7.5. It is documented
that keeping these fish in water with a pH value above
7.5 can cause skin and eye cloudiness.
Origin: Widespread throughout most of
the larger river systems of South America.
Temperature: 20 to 24ºC or 68 to 75ºF although
slightly warmer temperatures are also tolerated.
Size: Up to 920mm or 36”+
Sexing: There are no reported external
sexual differences. My own thoughts are that females tend
to be more heavily built or robust than the males, which
tend to be slender. There may also be differences associated
with the structure of the head as with the Synodontis
catfish, but further observations need to be made.
Feeding: Omnivore feeding on a very mixed and varied diet
including catfish pellets, earthworms, whole prawns, mussels,
floating sticks/pellets and snails. In their natural environment
they would feed upon snails, aquatic plants and fruits.
Breeding: There are no known aquarium
spawnings of this catfish. This is most likely due to
the size that these fish can attain and hence the subsequent
size of aquarium in which to spawn them.
Compatibility: Ideally suited to life
with other large fish. These catfish are not predatory
but would mistakenly take a smaller fish if hungry.
Suggested Tankmates: Other large catfish such as Oxydoras
niger, Leiarius pictus, Perrunichthys perruno, Megalodoras
urunoscopus, Oscars and larger characins.
Furniture: Large pieces of bogwood are
ideal. Large diameter pipe can be used but it should be
large enough for the catfish to easily fit in without
becoming stuck. I created two shady areas within my tropical
pond, by covering the ends with decking, where these catfish
preferred to hide until feeding time.
Comments: The Common Bacu or Pterodoras
granulosus is another of my favourite large catfish,
which I have had the pleasure to keep. At one time I had
three of these “Gentle Giants” housed within
my 12’ x 3’ x 4’ tropical pond. They
varied in size from approximately 600mm (24”) to
900mm (36”). My observations of these fish suggested
at the time that I had two females and one male, as two
were rather fat whilst the other was more slender. I did
not see any obvious signs of spawning activity, but these
catfish were quite happy to swim around the pond together.
Whilst fish collecting in Peru, we caught a couple of
these catfish on rod and line. These catfish were to spend
the next few days on board the accommodation for the week,
only to be returned to the point at which they were caught
originally. I decided that the three specimens that I
had at home at that time were enough and that they would
be better off swimming in the Amazon! In South America
the local inhabitants would catch and eat these catfish,
and as you can imagine a large specimen would feed a whole
family for a few days. Seeing these catfish in their natural
habitat was an amazing experience, one that will live
with me for a long time to come. These catfish are found
throughout the river systems of South America. The colour
pattern of these catfish varies depending upon the location
that they originate from. These fish are usually a muddy-brown
colour with some darker spots over the body and fins.
As they mature the spotting tends to fade. Juvenile specimens
tend not to be as dark coloured as adult fish; in fact
the two specimens caught in Peru were light brown/tan
in colouration. The body of these catfish is best described
as being robust. The body is naked i.e. it is devoid of
scales, but the skin is very thick and tough. There are
between 23 and 28 shallow lateral plates known as scutes
along the length of the body. Their eyes are very small
in comparison to the rest of the fish and they have three
simple pairs of barbels. They have a deeply forked caudal
fin, which also helps to distinguish this fish from other
large doradids. In their natural habitats these catfish
are migratory, shoaling in large numbers as they make
their journeys upstream to spawn.
Megalodoras urunoscopus (Eigenmann,
1925)
Common Names: Mother of Snails Catfish,
Giant Raphael Catfish, and Giant Talking Catfish
Family: Doradidae
Synonyms: Megalodoras irwini
Water: pH 6.5-7.5
Origin: Peruvian and Brazilian Amazon,
Maranon and Guianas
Temperature: 22-26ºC (72-79ºF)
Size: 61cm (24”)
Sexing: There are no reported external
sexual differences. My own thoughts are that females tend
to be more heavily built or robust than the males, which
tend to be slender. There may also be differences associated
with the structure of the head as with the Synodontis
catfish, but further observations need to be made.
Feeding: Their natural diet includes
crustaceans such as aquatic snails, which should be included
as part of their captive diet. In the aquarium they will
feed on sinking catfish pellets, floating food sticks,
whole prawns, earthworms, chopped and whole mussel. They
also relish sinking tablet foods.
Breeding: There are no known documented
aquarium spawnings to date, although there may be some
breeding-taking place in Czechoslovakia using hormone
inducement.
Compatibility: Ideally suited to life
with other large fish. These catfish are not predatory
but would mistakenly take a smaller fish if hungry.
Suggested Tankmates: Other large catfish
such as Oxydoras niger, Leiarius pictus, Perrunichthys
perruno, Oscars and larger characins.
Furniture: Large pieces of bogwood are
ideal. Large diameter pipe can be used but it should be
large enough for the catfish to easily fit in without
becoming stuck.
Comments: This particular catfish is
perhaps one of the more colourful of the members of the
family Doradidae, and is also one of the larger species
hence the common names. This catfish is quite often described
as being one of the “Tank Busters” due to
the fact that it can grow up to 610mm or 24” standard
length (from the tip of the snout to the base of the caudal
peduncle). The local name given to this fascinating catfish
is “Key-way-mamma” which refers to the common
name of “mother of the snails”. The reason
for this common name being due to the fact that when a
specimen was examined the intestine was lined with large
aquatic snails along its length. Some of you reading this
information may be wondering why the scientific name for
this fish is not Megalodoras irwini, the reason
being that the name has been recently changed and that
the old name is now a synonym. It has an interesting colour
pattern with dark brown markings on a light brown background.
The body and head are covered in dark brown to black blotches.
The ventral (underneath) region of this catfish has a
mottled pattern, which is dark brown in colour. The fins
are mottled or spotted irregularly with black coloured
markings. The pectoral fins tend to be lighter in colour
towards the base and darker towards the edge. The adipose
fin is light brown at the top edge of the keel and darker
towards the base. Megalodoras urunoscopus has
15-18 lateral scutes that increase in size towards the
caudal fin. There are many caudal fulcra or bony plates.
There are no plates above or below the caudal peduncle.
The adipose is described as continuing forward in the
form of a hard keel. This catfish has two pairs of barbels,
one pair maxillary and one pair mandibular. Keeping Megalodoras
urunoscopus is relatively easy assuming that you
have the available tank space in which to keep them at
their optimum. Ideally they are best housed in an aquarium
which is at least 72” x 24” x 24”. The
preferred substrate is sand such as BD Aquarium sand,
although rounded gravel can also be used. They tolerate
a wide range of water conditions, but do like to be able
to hide away. Aquarium décor should include bogwood
and if you don’t mind the appearance large diameter
pieces of drainage pipe. This species of catfish despite
the size that it can attain is really a “Gentle
Giant” and can be kept with other large or medium
sized fish. They are not commonly available, if you have
the space for one or more as they do tend to like their
own company, they are well worth obtaining.
Merodontotus tigrinus (Britski, 1981)
Common name: Tigerstriped Catfish
Family: Pimelodidae
Synonyms: None
Water: pH 6.5-7.5
Origin: Rio Maderia in Brazil, Columbia
and Peru.
Temperature: 22-26ºC
Size: 600mm or 24”+
Sexing: There are no known obvious external
sexual differences.
Feeding: As these are predatory catfish
they prefer meaty foods such as whole prawns, mussels,
pieces of fish and earthworms etc.
Breeding: There are no records of aquarium
spawnings due to the adult size and price tag associated
with these fish.
Compatibility: Not compatible with other
pimelodids due to its territorial nature.
Suggested Tankmates: Anything that does
not constitute a meal, I would suggest some of the larger
Characins as opposed to any other catfish, which may compete
for territory. Most enthusiasts would keep this catfish
as a single specimen in a display aquarium.
Furniture: Large pieces of bogwood are
ideal. Large diameter pipe can be used but it should be
large enough for the catfish to easily fit in without
becoming stuck.
Comments: This magnificent catfish belongs
to the family Pimelodidae, representatives of which can
be found widespread throughout the rivers of South America.
The original specimens that were caught and described
by Dr Britski of the Sao? Paulo Zoology Museum were from
the Rio Maderia in Brazil. It was originally thought that
this was the only location where this species of catfish
was found, however this catfish is known to be collected
in Columbia and I personally have experience of Peruvian
exporters collecting these catfish in Peru. The original
fish were collected in 1978 by Michael Goulding. A publication
by Dr Dario Castro of the University of Bogotá
in 1984 recorded this catfish as being collected from
the lower Caqueta River in Columbia. Merodontotus
tigrinus is quite closely related to Brachyplatystoma
juruense, but has a longer upper jaw, and the first
rays of the dorsal and pectoral fins are described as
being flexible and not pungent. Both of these catfish
share a similar colour pattern of inclined stripes on
the body, although it has to be said that Merodontotus
tigrinus is the more striking of the two fish. Brachyplatystoma
juruense is quite often referred to as the “False
Tigrinus”. The colour pattern is outstanding with
a yellow to almost white base colour to the body with
black stripes. Most of the fins share this same colour
pattern of that of the body of this catfish. In their
natural habitat, however they grow well in excess of this
size and can attain lengths in excess of 600mm quite easily.
This catfish is perhaps one of the most expensive specimen
fish from this family of fish. The first specimen that
I ever saw back in the mid eighties had a price tag of
£1000, and I have recently seen specimens for sale
at between £500 and £600. Obviously consideration
needs to be given to the size of aquarium in which to
keep such a magnificent catfish as this, I would not recommend
anyone to keep one of these catfish in anything less than
a 72” x 24” x 24”. As well as the size
of aquarium good filtration is also very important in
order to keep a catfish such as this in perfect condition.
I would also suggest that sand such as BD Aquarium sand
be used as a substrate for the aquarium. This is a catfish
that I have not personally kept which probably has something
to do with the high price that these catfish demand. It
was whilst on my fish collecting trip to Peru that I found
out some little known information about this fish. The
exporter in Peru that specialises in large specimen fish
such as this informed us that they collect these catfish
as juvenile specimens from a local breeding area in the
river and grow them on for export. We were informed that
when collected at between 50 and 75mm they could be reared
successfully in the holding tanks and fed on their favourite
food of knife fish. This particular exporter found that
when collected at a size of around 300mm they did not
fare well and would not feed in captivity. The Peruvian
exporter keeps these catfish at his premises for around
six months before offering them for sale.
Leiarius
pictus (Muller
& Troschel, 1849)
Common Names: Sailfin Pimelodid, Saddle
Catfish, Painted Catfish, Sailfin Marbled Catfish
Family: Pimelodidae
Synonyms: Bagrus pictus, Leiarius
longibarbis, Sciades longibarbis, Sciades pictus, Sciadeichthys
pictus
Water: pH 6.2 to 7.5 and up to 18ºdGH
Origin: Widespread throughout the Amazon
and its tributaries, South America.
Temperature: 22 to 26ºC or 72 to
79ºF
Size: 600mm + or 24”+
Sexing: There are no reported external
sexual differences. My own thoughts are that females tend
to be more heavily built or robust than the males, which
tend to be slender.
Feeding: Carnivore feeding on a very
mixed and varied diet including earthworms, whole prawns,
mussels, floating sticks or pellets and catfish pellets.
In their natural environment they would feed upon other
fish.
Breeding: There are no known aquarium
spawnings of this catfish. This is most likely due to
the size that these fish can attain and hence the subsequent
size of aquarium in which to spawn them.
Compatibility: Ideally suited to life
with other large fish. These catfish are predatory and
could mistakenly take a smaller fish if hungry.
Suggested Tankmates: Other large catfish
such as Oxydoras niger, Pterodoras granulosus, Megalodoras
urunoscopus, Oscars and larger characins.
Furniture: Large pieces of bogwood are
ideal. Large diameter pipe can be used but it should be
large enough for the catfish to easily fit in without
becoming stuck. I have managed to create two shady areas
within my tropical pond, by covering the ends with decking,
where this catfish prefers to hide until feeding time.
Comments: The Sailfin Pimelodid or Leiarius pictus
is another of my favourite large catfish, which I have
had the pleasure of keeping within the confines my tropical
pond. It has to be said that this particular catfish was
a real character fish. I kept this catfish for six years,
after I was asked by my good friend Giles Barlow of Barlows
Aquatic Trading, to rescue this fish from one of his customers’
tanks. When I collected this fish it was approximately
16” long, and it was approximately 28” long
when it died, so as you can appreciate this is not a catfish
for your average sized aquarium. This catfish is sometimes
confused with Perrunichthys perruno (Reticulated
pimelodid) and Leiarius marmoratus (Marble antenna
catfish). The overall body colour of Leiarius pictus
is dark brown with darker spots, with a lighter underside
colouration. More noticeable in juvenile specimens this
catfish has two pale bands, the first extends from the
base of the dorsal fine spine toward the ventral fin,
and then laterally along the body to the base of the caudal;
the second thinner band lies parallel to the first originating
from the base of the third to sixth soft dorsal fin rays.
Large round spots can be seen in the dorsal, adipose and
caudal fins, whilst the anal and ventral fins have much
smaller spots. The barbels have a ringed pattern to them
alternating light and dark colouration. With regard to
the anatomical characteristics of Leiarius pictus
the head is described as being narrow and flattish above.
The upper jaw is slightly longer than the lower jaw. The
maxillary barbels in adult specimens extend just beyond
the dorsal fin; the inner mandibular barbels extend to
the base of the pectoral fin whilst the outer mandibular
barbels extend to the middle of the pectoral fin. In juvenile
specimens the maxillary barbels can be seen to extend
well beyond the tips of the caudal fin. This catfish has
a large sail-like dorsal fin with 9 – 10 soft rays
hence the common name of Sailfin Pimelodid. The caudal
fin is described as being deeply forked. As mentioned
above there are a number of differences between juvenile
and adult fish, such as the fact that the barbels shorten
in ratio to body size in adults, and the colour is less
intense in adult fish. The lobes of the caudal fin are
more rounded in young specimens whilst they are more pointed
in adult fish. These catfish are real character fish,
but can be very territorial especially towards other pimelodids.
My own catfish had a very understanding relationship with
a large Oscar, basically if the Oscar got in the way at
feeding time, the Leiarius pictus would take
the Oscar in its mouth and swim around the pond a couple
of times before depositing the disorientated fish in one
of the corners! A fascinating catfish to observe and an
amazing site to see the barbels protruding from the surface
of the water at feeding time. I was able to feed this
fish by hand just as long as one of the larger doradids
did not spook the fish at the same time. It is documented
that Leiarius pictus suffer from claustrophobia
caused by the fact that all too often these catfish are
kept in accommodation where their maxillary barbels touch
the front and back of the aquarium, thus stimulating both
barbels at the same time causing the catfish to become
confused! If this is the case it has been reported that
these catfish will try to exit the aquarium, and it is
therefore recommended that tight fitting covers be added
to the aquarium. This did not appear to be a problem in
my uncovered tropical pond!
I will concentrate on some African and Asian tank busters
in order to continue the debate in the second part of
my article.
Chris Ralph 26th February
2005
Previously published in the September 2005 edition of
Practical Fishkeeping magazine.
Photo Credits:
Oxydoras niger: Danny Blundell
Pterodoras granulosus: Danny
Blundell
Megalodoras urunoscopus: Danny
Blundell
Merodontotus tigrinus:
Chris Ralph
Leiarius pictus: Allan James
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