I am going back to a not too distant memory when I
was lucky enough to take a fish catching trip to the
Peruvian Amazon in 2000 and to attain a catfish that
seemed to appear in every catchment net back then,
the "Croaking Spiny Catfish", Amblydoras
This species from
the Doradidae family were very abundant in the Rio
Orosa, a small tributary of the Rio Amazonas down
the river from the city of Iquitos in Peru. We were
catching very small juveniles about a ½ mile
down this river in a small flooded cocha near the
head of a small lake. The month was July and the waters
were supposed to be quite low but were a bit higher
than normal for this time of year. These catfish must
have spawned a month or two earlier when the waters
were higher and having received fresh cool water from
the rising floods.
They can be quite
variable in colour pattern as they are widespread
in the Amazon region. Below can be seen one of my
6 sub-adults from this catchment. This fish was approximately
2 years old when photographed.
In common with
most of the Doradidae family it can create a sound
by grating its fin bones in each socket and amplifying
the noise via the swim bladder which is one reason
why it got its common name of the
Croaking Spiny Catfish
sub adult in aquarium
Again in common
with most members of this family, they are easy to
keep but are very secretive
and you may not see them from one week to the
next. I have found after a considerable
time in captivity that they will venture out at spead
to pick up any tasty morsels that is making its way
to the substrate.
December 2009. You
may have known this Dorad as Platydoras hancockii
or Amblydoras hancockii in the past but
it has now been placed back to the Amblydoras
genera as this species was misidentified, and is
actually Amblydoras nauticus.
Spiny Catfish, Marbled
nauticus, Zathorax nauticus
Upper Amazon River basin, Peru. Type locality:
Nauta, (Upper Amazon).
A 1/11; P 1/5. Dorsal fin-spine toothed on both anterior
and posterior surfaces. Spinous scutes confined to
the posterior half of the body. 3 pairs of barbels.
Brown body which is quite
variable. Two black
blotches, one below adipose fin and a large one
at the caudal peduncle. Black line runs from caudal
peduncle along body just below lateral line which
stops posterior to the dorsal fin and takes a downward
turn. Irregular spots and blotches to the head area.
Care & Compatibility
No problem in a normal community
tank as long as you can give them plenty of hiding
places to make them feel more secure.
There are no known
documented spawnings of this catfish in aquaria, but
it is reported [Hancocki] that they construct a nest
of leaves in the substrate and the eggs are laid during
wet weather (flooded season), and once laid the eggs
are covered with leaves. Both parents guard the eggs
and emerging fry.
It is said that
the females underside is a dirty white colour whereas
the males have a flecked pattern.
A good quality flake food,
frozen blood worms and tablet food. Live worms such
as whiteworm and cut up garden worms.
The head end.
Posterior:The tail end. Scutes:
Bony covering. Swim Bladder:The
air sac that gives fish buoyancy and balance. Acts
as sound resonator in some fish.
Amblydoras:Amblys = blunt; doras
= leathery skin, cuirass. nauticus: Named after
the type locality, the town of Nauta, located on the
north bank of the major Upper Amazonian tributary.
Gunther;Freshwater Fishes of the World no.1 Catfish
Study Group; Information
Sheet no.15. Conservación
seris de Guías Tropicales De Campo. Pecos del
medio Amazonas Región de Leticia. 546 p.