he common comment of "A face only a Mother could
love" would certainly fit our factsheet of the
month for May 2023. A very special looking catfish
that always turns heads when viewed for the first
time. The catfish we are talking about of course is
the "Gulper Catfish" Asterophysus
species is unusual among auchenipterids in having
an enormous gape, a very distensible belly and, despite
its short body, the ability to prey on large fishes.
The mouth of this species is reminiscent of the Salmonidae
(Salmon) family which is a good identification indicator.
Very predatory which is unusual for a member of the
The catfish Asterophysus batrachus (Auchenipteridae)
has a huge mouth gape and is able to ingest very large
prey. However, how it catches and positions such prey
in its stomach remains unrecorded. We studied the
predatory behavior of A. batrachus under
aquarium conditions and found a novel feeding mode
for piscivorous Neotropical catfishes. It uses its
cavernous gape in a remarkable way, scooping up large
unaware prey headfirst, then taking advantage of the
fleeing response to further the prey’s advance
into its stomach. Positioning of the prey results
from additional escape movements into the very distensible
belly of the catfish. The prey ends up folded in the
stomach with its head and tail pointing towards the
head of the predator (Zuanon, Jansen and Sazima, Ivan,2005).
fasting catfish occasionally takes in water, bulging
its belly considerably (“belly ballooning”).
After a while the fish expels the water entirely,
along with a little mucus and a few small fragments
of food. The wrinkled belly quickly regains its former
shape. Because of its huge mouth, ability to swallow
large prey and overall appearance, we name A.
batrachus the ogre catfish (Zuanon, Jansen and
- close up of the wide mouth
This species is
monotypic (one in the genus) and the subfamily of
and Negro River basins. Type
Indigenous Territory (Portuguese: Terra Indígena
Cué-Cué/Marabitanas) is an indigenous
territory in the northwest of the state of
Amazonas, Brazil. There were extended delays
while the territory was being identified and
formally declared. The Cué-cué/Marabitanas
Indigenous Territory is in the municipality
of São Gabriel da Cachoeira, Amazonas.
The territory has an area of 809,000 hectares
(2,000,000 acres). The Rio Negro flows
through the northern portion of the territory,
which is bounded by Colombia on the north
and Venezuela on the northeast. The Rio Negro
defines the western boundary. The settlement
of Cucuí on the Rio Negro is in the
northern portion of the territory. Highway
BR-307 runs through the eastern portion from
the settlement of São Gabriel da Cachoeira
up to Cucui. In the east, 25% of the territory
overlaps the Pico da Neblina National Park.
Catfish, Gulper Catfish
America:Orinoco and Negro River basins. Type
locality: Marabitanos, Brazil.
10-13 branched anal fin rays.
The anteriorly placed and elongate pharyngeal tooth
plates, as well as the bands of villiform teeth on
the premaxilla and dentary prevent prey from slipping
out of the catfish’s mouth. The mouth has a
very wide gape. Backward oriented suspensorium axis
(formed by the hyomandibular-quadrate-articular bones);
a loosely connected dentary symphysis; elongate and
anteriorly placed pharyngeal tooth plates; slight
mobility of the premaxillae along the symphysis; a
narrow, v-shaped and anteriorly directed scapulocoracoid
+ cleithrum bridge, with a flexible connection of
the opposite halves (i.e., not sutured); a well developed
sphincter at the opening of the oesophagus.
Ground colour black with
a white belly. A white dotted lateral line adorns
the body from a line adjacent to the first dorsal
ray fin to the caudal peduncle.
Care & Compatibility
would need to choose tank mates very carefully as
they will attack fish that are even larger than them
and try and take them into their large expanding mouth.
Would probably be better in a species tank on their
In sexually mature
males there is a thickening to the first two rays
of the anal fin.
shrimp, prawns, earthworms, daphnia and fish. As they
get older they will need to be fed less as they will
regurgitate their food if fed too much, so feeding
every other day is best.
fin:The median, unpaired,
ventrally located fin that lies behind the anus, usually
on the posterior half of the fish. Caudal peduncle: The narrow part
of a fish's body to which the caudal or tail fin is
attached. Cleithrum: The major bone of the
pectoral girdle, extending upward from the pectoral
fin base and forming the rear margin of the gill cavity,
also: the principal bow-shaped bone of the prectoral
girlde, dermal in origin, forming the rear margin
of the gill cavity. It articulates dorsally with the
supracleithrum and ventrally with the scapula and
coracoid. Coracoid: Middle and lower section
of the pectoral girdle. Dorsal fin: The primary rayed fin(s)
on top of the body. Lateral line:A
sensory line, along the sides of the body. Oesophagus: The oesophagus (gullet)
is part of the digestive system, which is sometimes
called the gastro-intestinal tract (GI tract). The
oesophagus is a muscular tube. It connects your mouth
to your stomach. When you swallow food, the walls
of the oesophagus squeeze together (contract). Premaxilla: In relation to the premaxilla
(an upper jaw bone) e.g. premaxillary tooth band.
Greek, aster = star + Greek, physa = tube, pipe, channel. batrachus: From batrachus,
a frog; frog-like.
(2021): Banjos, Dorads and Woodcats. Aspredinidae,
Doradidae and Auchenipteridae Catfishes. ATS-Aquashop,
Neustadt am Rübenberge: 1-300.
Wikipedia contributors. "Cué-cué/Marabitanas
Indigenous Territory." Wikipedia, The Free
Encyclopedia. Wikipedia, The Free Encyclopedia,
12 Sep. 2021. Web. 9 Apr. 2023. Zuanon, Jansen and Sazima, Ivan:
2005. The ogre catfish: prey scooping by the auchenipterid
Asterophysus batrachus. aqua, Journal of Ichthyology
and Aquatic Biology.