month we again return to the family Callichthyidae
and a request for one of the most misidentified species
from this family and one that I must confess has led
me to many sleepless nights (how sad is that :-)
There has been a very good paper written on this very
subject matter by U.K.aquarist, Steven Grant, and
I will not go over too much of the ground that Steve
has (scientifically) covered, but suffice to say I
will try to attempt to clear up a few misconceptions
on this long known Corydoras.
The main misidentification
centres around a Corydoras that exists sympatrically
in some of the same waterways as C. ambiacus
and that is Corydoras
Steindachner, 1876. There is a vast amount of the
so-called spotted species that are very much alike
but these are the two that are the most erroneously
ambiacus was described by Cope as "slightly
concave on the elongate muzzle". In other words
our species has a a short snout but elongated upwards
towards the end of its snout as in the above picture.
Corydoras agassizii tends to have a more
rounded snout. As mentioned previously the two species
are spotted, C. ambiacus having many small
brown spots scattered over its body while C. agassizii
has larger spots which basically forms three longitudinal
rows of black blotches. Another point is the black
blotch to their dorsal fins. C. ambiacus
tend to have the blotch on the first three or four
rays of the fin and also down into the top half of
the body, whereas C. agassizii tends to have
it more concentrated on the dorsal fin. You may say
to yourself that that is fairly rudimentary evidence,
but it is not as easy as that as these two species
seem to overlap on colour variations and body shapes
and even the Ichthyologists have problems sorting
them out, so the jury is still out on them until someone
carries out a field trip to collect specimens of these
two species, and to facilitate a morphometric and
meristic study of them.
showing Corydoras agassizii on left
and Corydoras cf. agassizii on
the right both in Lineage 8 Sub-clade 4
Acknowledgements: Steven Grant and
Ian Fuller for permission to use their photographs.
is placed in Lineage 8 sub
clade 4 which comprises the "intermediate long-snouts"
with deeper bodies. It also includes Brochis
in sub-clade 1 which was synonymised with Corydoras
by Britto in 2003 but in time there will be a revision
which will resurrect Brochis (Cope, 1871)
to full genera again.
Rio Panayacu, a tributary of the Rio Napo which extends
out of the North Western part of Peru and also
the Rio Yasuni. Peru, in the Rio Ampiyacu and the
Rio Nanay close to the City of Iquitos, capital of
the Peruvian Amazonia. Rio Yavari near the village
of Benjamin Constant where the three countries of
Peru, Colombia and Brazil meet. Rio Tamya around the
area of Masisea and a tributary of the Rio Ucayali.
Male: 6.0cm (2¼ins)
Female: 6.5cm (2½ins)
Dorsal: 1/7: Anal: 1/6: Ventrals:
1/6: Pectorals: 1/9. Form stout, compressed, dorsal
line arched, front convex at orbit, slightly concave
on the elongate muzzle.
Straw coloured with numerous
indefinite brown spots on the sides. Dorsal fin
with large black spot covering anterior half, which
also expands on the dorsal region round the base
of the fin. Four vertical brown bands on caudal
fin; anal spotted. Cheeks with blue reflections.
Care & Compatibility
Keeping the Black-spot Catfish
is no more difficult than any other of the Northern
Amazonia species of Corydoras and it will
make a nice addition to your community tank. Keep
at least 6 of them, as with most Corydoras they
like their own company, then you will find that they
will not be so shy and you can see them during the
day picking away at any tiny morsel that has been
missed by the other occupants of your tank. If you
keep Barbs such as the "tiger" keep a close
eye on their dorsal fins as this is a waving flag
to some of the more nippy species, then you will have
to make up your mind to either move your Barbs, or
your catfish, to another tank
Like to lay their
eggs (300 or more) in the direct flow of a filter
usually high up on the glass where the flow strikes.
Eggs will hatch in 3 to 4 days I have not come across
any detailed description of the breeding of this species
but below is a scenario that you could follow for
many of the Corydoras species.
Set them up with
preferably more males than females ( a ratio of 2:1
is good ) in a 18" x 12" x 12" tank
with either fine gravel or sand with either sponge
filter or a corner filter box with a good current.
Install some java moss or wool mops, this gives the
females a choice of where to place their eggs but
you will probably find that they will mostly lay them
on the glass anyway.
in the mid-seventies is good with a p.H around about
the neutral (7) mark. Feed a diet of frozen or live
food such as bloodworm, whiteworm (sparingly because
of the fat content) grindleworm, daphnia and a good
quality flake or tablet food.
Make a 50% water
change, when you notice the female(s) have fattened
up, with water that is cooler so as to bring the temperature
down. A good idea is to also add a small internal
filter to push the water around the aquarium which
will also oxygenate it.
you can either take the adults out and leave the eggs
in the main tank or reverse it and take the eggs out
by rolling them of the tank sides with your fingers
into a small hatching tank, you can then decide to
add a anti-fungus remedy or to leave alone. If you
make the wrong choice and the eggs fungus you will
get another chance as once Corydoras start
to breed the first time they will carry on using the
A good quality flake food and
tablet food for adults with sparodic feedings of frozen
or live food will keep your Corydoras in good
health. Feeding the fry after they use up their yolk-sac
with brine shrimp naupli, microworm and fry flake
Cory = helmeted;doras = leathery skin,(helmeted
Doras) cuirass. ambiacus: After the River
Ambiacu, currently spelled Rio Ampiyacu.
Markos & Taylor, Martin (2011). Evolution,
ecology and taxonomy of the Corydoradinae revisited.
Cope, E.D;1872. On the fishes of
the Ambyiacu River. Proc. Acad. Nat. Sci. Phila.
Fuller, I.A.M. & Evers, H-G: 2005 Identifying
Corydoradinae Catfish 384 p
Grant, Steven;The variable Corydoras
ambiacus, Cope, 1872. Catfish Compendium
Vol.1 No.2; Published by D.M.A.Wright, 22 June 2000. Ian A. M. Fuller & Hans-Georg
Evers (2011). Identifying Corydoradinae Catfish
Supplement 1. Ian Fuller Enterprises. Seus, Werner; Corydoras, The most
popular armoured catfishes of South America. Dähne