here are a number of catfish
that belong to the family Doradidae. Quite
often these fascinating catfish are referred to as
"Doradids", "Dorads", "Talking
Catfish", "Thorny Catfishes" and other
names, which cannot be mentioned, as they are too
rude! This group of catfish are found throughout South
America. There are small doradids and large doradids
commonly offered for sale at most good aquatic retailers.
The problem with some of the larger species such as
Pseudodoras niger (Mother of Snails Catfish/Black
Doradid) and Pterodoras granulosus (Common
Bacu) is the fact that they would soon outgrow a 72"x
24" x24" aquarium and are therefore not
ideally suited to life in an aquarium unless you can
provide a large enough aquarium or tropical pond to
house them in. As I do not wish to encourage any unsuspecting
aquarist to keep large catfish I will concentrate
this article on some of the smaller representatives
of this family of fish. Those of you that know me
will already be aware that this family of fish is
perhaps my favourite, as I am unable to resist walking
past a dealers tank without looking to see what doradids
lurk behind the décor.
Why are they referred to as
"Talking Catfishes" I hear you ask? I will
now attempt to answer this question. Doradids have
two ways in which they can produce "Talking Sounds",
which subsequently gives them their common name. The
first way of communicating sound is by the fish partially
locking their pectoral fins in their sockets, and
then the action of moving the fins, the fin spines
grate against the socket producing the sound. The
second way, in which these fish produce sound is via
a mechanism known as the "elastic spring mechanism",
there is a muscle that is attached to the rear of
the fishes skull at one end and to the anterior of
the swimbladder at the other end. The fish is able
to quickly contract and relax this muscle and as a
result it can make its air filled swimbladder resonate
to produce sound. These catfish use these methods
of communication as a means of self-defence against
would be predators and also as a way in which they
can find conspecifics in its natural environment (or
aquarium). The doradids can also be described as narrow-breasted
or broad-breasted. The narrow-breasted species tend
to have feathered barbels a characteristic that the
broad-breasted species do not posses. With the broad-breasted
species the width between the base of the pectoral
fin spines tends to exceed the length of the head.
One of the main features of this
family of catfish is the fact that they posses bony
projections along the lateral length of their bodies.
These bony projections are known as "scutes",
which are very sharp just like thorns. These scutes
give this family of catfish an almost prehistoric look
about them. Care should be taken when removing these
fish from an aquarium as they all too often get themselves
snagged up in nets. When these catfish are frightened
they immediately lock their pectoral and dorsal fin
spines erect. These fins have serrated edges and when
locked makes the fish safe from would be predators.
If nets have to be used then they should be very fine
meshed in order to prevent the scutes and fin spines
from penetrating it. Some aquarists prefer to pick these
catfish up by their dorsal fins taking care not the
get their fingers trapped between the pectoral fins
and the scutes on the body of the fish, as believe me
this can be a very painful experience! If you can use
a plastic container or a plastic bag in which to chase
the fish this is perhaps the best way of removing the
fish from the aquarium. When removing the larger species
it is perhaps best to wrap the fish in a bath towel(s)
and lift it out of the water (this tends to be a two
person job one lifting the head end the other the tail
end taking care not to cut your hands on the razor sharp
scutes.
The ideal set-up for these catfish
would be an aquarium with a sand substrate such as BD
Aquarium sand or fine gravel. Décor should include
bogwood in which the catfish will hide, smooth rocks
to avoid damaging the bodies of these fish. Some aquarists
use plastic or clay pipes for their catfish to hide
in, if these materials are to be used please ensure
that they are large enough to allow the catfish to be
able to get out of. I have known a number of people
to lose their catfish as they have become too large
to get out of the pipe and they have subsequently become
stressed and died. Wherever possible use large diameter
pipes if they are to be used. I would personally recommend
an aquarium that is at least 36" x 15" x 12"in
order to keep these catfish satisfactorily. The ideal
water conditions are pH 6.5-7.5, temperature in the
range 22-26ºC or 72-79ºF and dH up to 15º.
These catfish thrive on a mixed and varied diet that
includes sinking catfish pellets, granular foods, flake,
tablet foods, aquatic snails, shredded prawns, earthworms
and frozen foods such as bloodworm. As sand has been
mentioned as the ideal substrate for these catfish I
would suggest that internal power filtration or external
canister filtration be used, as under gravel filtration
would not be efficient as the sand would cause it to
clog. Weekly or fortnightly 20-25% water changes should
also be undertaken to ensure good water quality at all
times. When undertaking water changes always ensure
that you use a water dechlorinator, preferably one that
will treat both chlorine and chloramines, prior to adding
the fresh water to your aquarium.
As promised I will now mention
a few species that will not grow into "Tank Busters"
and would be ideally suited to life in a community type
aquarium. Please bear in mind that whilst these catfishes
are not predatory they will eat any unsuspecting fish
small enough to fit inside their mouths. This said I
have kept some of the smaller doradids in with small
fish, BUT I am not recommending that you should. I will
begin with some of the more commonly seen species and
mention also some that are not so readily available.
Platydoras
armatulus commonly
known as the Humbug Catfish, the Striped Talking Catfish
or Striped Raphael. This particular catfish is readily
available from most good aquatic retailers, and is perhaps
the most commonly seen representative of this family
of catfish. Like most of the doradids it prefers to
be kept in a small group, although there may be the
odd squabble over territory. The natural habitat for
this catfish is the river system of South America from
Peru to Brazil. Platydoras armatulus can attain
a length of 200mm or 8". I have found that when
kept in small groups these catfish will soon rid an
aquarium of an aquatic snail problem. Single specimens
will relish snails but will be unable to rid an aquarium
of snails single-handed! Price guide £4-£10
depending upon size.
Orinocodoras
eigenmanni is
more commonly known as the Raphael Catfish. This catfish
is not commonly available but to the trained eye the
odd specimen can be picked out amongst imports of
Platydoras costatus, which has been the way
in which I have gradually obtained a group of them.
Orinocodoras eigenmanni has a more pointed
snout and its scutes tend to be smaller than those
of Platydoras costatus. There are other differences
as well such as the length of the adipose fin and
the shape of the caudal fin, which when viewed side
by side is quite apparent. Like most of the doradids
these catfish also like to be kept in small groups,
which can be difficult when only the odd one or two
specimens are available. Fortunately these doradids
are quite happy to shoal with Platydoras costatus.
The natural habitat for these catfish is the Orinoco
River system in Venezuela hence its name Orinocodoras.
This catfish can attain a length of 175mm or 7".
Like the other doradids this catfish also relishes
aquatic snails as part of its mixed and varied diet.
Price guide £5-£15 depending upon size
and if the retailer is aware that this fish is amongst
Platydoras costatus.
Agamyxis
pectinifrons
is commonly known as the Spotted Talking Catfish,
White-spotted Doradid and Spotted Raphael. This particular
catfish is also quite often available at most good
aquatic retailers. The colour pattern tends to differ
slightly from individual to individual, but is quite
eye catching being jet-black body colour with white
to creamy coloured blotches along the body and fins.
Again this catfish prefers its own company so the
aquarist should ideally keep them in small groups
of between 4 and 6 specimens. The natural habitat
for these catfish is throughout the river systems
of South America notably in Peru and Pebas. This particular
species can attain a length of 140mm or 5½".
These catfish thrive on a mixed and varied diet including
aquatic snails. Price guide £4-£10 depending
upon size and availability.
Platydoras
hancocki is commonly
known as Hancock's Catfish or Talking Cat. There is
also reference made to this catfish under the name
of Amblydoras affinis just to add to the confusion.
This catfish is occasionally seen at some retailers
and is quite often imported at no more than 50mm or
2" in length. This species can attain a length
of 100mm or 4". Again another catfish that fares
better in small groups therefore I would recommend
keeping between 4 and 6 specimens together. The natural
habitat for these catfish is widespread throughout
the rivers of South America from Guyana to Brazil.
This particular species prefers water that is neutral
and soft with dense vegetation for it to hide amongst.
Again these catfish thrive on a mixed and varied diet
that includes aquatic snails. Price guide £5-£10
depending upon availability.
Anadoras grypus
is commonly known as the Dusky Doradid. This catfish
is not very often available for sale to the hobbyist.
The odd one or two sometimes appear amongst shipments
of Amblydoras hancocki, which as juvenile fish
share a similar colour pattern. Whilst collecting
fish in Peru I was able to collect large numbers of
what initially appeared to be Amblydoras hancocki,
but which later turned out to be Anadoras grypus.
The specimens collected were approximately 25mm or
1" in length. This particular species can attain
a length of 150mm or 6". Another peaceful doradid
that prefers to be kept in groups of at least 6 specimens.
The natural habitat for these catfish is South America,
widespread throughout the Amazon Basin. As with Amblydoras
hancocki these catfish prefer neutral and soft
water conditions with plenty of plant cover. They
will thrive on a mixed and varied diet including aquatic
snails and bloodworm. Price guide £8-£20
depending upon availability.
Opsodoras
stubeli is commonly
known as the Feather Barbels Catfish. This is another
species that is not readily available to the hobbyist,
but is a very peaceful addition to a community aquarium.
This species can attain a length of 115mm or 4¾".
Another doradid that prefers safety in numbers assuming
that you can purchase them. I would recommend that
you keep at least 4 specimens together. The natural
habitat for these catfish is the rivers of Peru and
Ecuador. Good water quality is required by these fascinating
catfish, as is a diet that includes finely shredded
shrimp and bloodworm. Price guide £ 8-£15
depending upon size and availability.
Acanthodoras
cataphractus
is commonly known as the Painted Talking Catfish and
is also sometimes referred to as the Milky Cat. This
catfish is occasionally available to the hobbyist.
It can attain a length of 150mm or 6". I have
kept these catfish in small groups of 4 specimens
when numbers have been available to purchase, otherwise
I have kept them with the other species of doradid
already mentioned. The natural habitat for these catfish
is South America throughout the Amazon River estuary.
This species fares well on a mixed and varied diet.
Price guide £8-£15 depending upon availability.
There
are a number of other species of doradid available
to the hobbyist in small numbers, which is why I have
concentrated this article on those species mentioned
above. I hope that this will give you an insight into
this fascinating group of catfish and that some of
you reading this article will take up the challenge
of keeping them.
This article also appeared in the U.K. fishkeeping
magazinePractical
Fishkeeping.