his is certainly a catfish for the most avid catfish
enthusiast and not a species you can take lightly
and introduce to your community tank as this character
will make short work of any smaller fishes but would
be a good candidate for a large aquarium of 6' 0"
(180cm) or bigger. We are of course talking about
the Pac-Man Catfish, aka, Lophiosilurus
to Pseudopimelodus but the head is very large
and flattened and is the only species in this genera.
Dorsal fin short and the caudal fin is rounded. The
juveniles look similar to the Chaca genera
from Asia and like them are very predatory.
There are a few
discussions on the meaning of the common name of "Pac-Man
catfish" but the most popular seems to refer
to the big mouth that is wide and long, and relates
to the monsters of the Arcade game from the eighties.
This is a species for the aquarist with an acquired
taste as It will find Lophiosilurus alexandri
covered in sand most of the time.
alexandri have been bred under laboratory conditions
and they, experience impressive changes in body shape
during development, becoming extremely depressed when
fully developed. It is an ideal species to observe
the morphological changes during ontogeny, and to
seek solid interpretations on the polarity of characters.
Changes in body shape, position of mouth and eye,
morphology of fins and pigmentation were observed
during the development of Lophiosilurus.
Larvae (5.7–11.2 mm standard length) had pigmentation
concentrated on the head and parts of body, eyes small
and pigmented, short barbels, and well-developed finfold.
Juveniles (15.9–28.1 mm standard length) had
body shape similar to adult, with head depressed and
bearing bony ridges, large mouth, dorsally-oriented
eyes, small barbels and well-developed shoulder bulges
(cleithral width). The greatest morphological changes
in the development of L. alexandri occurred
during the postflexion larval stage. Relative to standard
length, measurements of snout length, head depth and
body depth are smaller in juveniles than in larvae,
but body width is larger. New interpretations on the
phylogenetic characters related to these changes are
provided in view of the two alternative hypotheses
of the evolution of Pseudopimelodidae. (Assega
FM et al. 2016). For further reading search
for Assega FM, Birindelli JLO, Bialetzki A,
Shibatta OA (2016) External Morphology of
Lophiosilurus alexandri Steindachner, 1876 during
Early Stages of Development, and Its Implications
for the Evolution of Pseudopimelodidae (Siluriformes).
Lateral view of larvae
of Lophiosilurus alexandri: a) newly hatched,
MZUEL 5725; b) one-day old, MZUEL 5681
alexandri 17 days after hatching, MZUEL 5686,
early mid-stage of postflexion: a) lateral view; b)
dorsal view of anterior region; c) left pectoral fin
in dorsal view
alexandri juvenile, 60 days after hatching, MZUEL
5694: a) lateral view; b) dorsal view of head; c)
dorsal view of left pectoral fin. Small dorsal and
ventral procurrent rays not visible
Distrbution:São Francisco River basin, Brazil.
Aus Brasilien, wahrscheinlich aus dem Amazonenstrome
(From Brazil, probably Amazonus).
Due to its excellent flavour
and the consistency of its flesh, this species has
good potential for intensive aquaculture. Every
year, juvenile Lophiosilurus alexandri
are released into the São Francisco from
a hatchery associated with UHE Três Marias
as a compensatory measure for construction of the
hydroelectric power plant.
Due to the latest paper by Oscar A. Shibattaet al. (Dec. 2021) there are now five species
in this genera with four of them now being being
synonymized from CephalosilurustoLophiosilurus.
The recovered phylogeny of the genus was (L.
fowleri, and L.
São Francisco River basin. Type locality:
Aus Brasilien, wahrscheinlich aus dem Amazonenstrome.
Very large and flattened head.
Occipital process meets the predorsal plate. The eyes
are minute and the maxillary and postmental barbels
extend only to the posterior margin of the orbit.
The gape of the mouth is oblique and the lower jaw
projects. Both margins of the pectoral spines are
serrated. Dorsal fin is short and the caudal fin is
Sandy coloured all over with
small dark spots.
Care & Compatibility
Not to be kept with fish that
are too small as they will be eaten, better to be
kept on their own or with large non-aggressive species.
Would need a large aquarium as this species grows
to 70cm. (28ins) SL.
Large yolk sac
persistent on day 4, much reduced at day 9, and completely
consumed within the 13th day of development. Non-migratory
and its reproduction involves the construction of
a circular nest depression (40–50 cm diameter
and 8–10 cm depth) in a shoal area. Spawning
is parceled and the female lays large adhesive eggs
(3.1 to 3.6 mm) in the center of the nest, which are
then guarded and maintained by the male. Upon hatching,
the larvae remain at the bottom of the nest and do
not move vertically into the water column.
Live foods such as earthworms
and frozen foods.
Tail. Cleithral: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. Dorsal fin:The
primary rayed fin(s) on top of the body. Lateral line: A sensory line, along
the sides of the body. Occipital: A median bone on the upper
surface of the back of the head; pertaining to the
The paired fins just behind the head.
FM, Birindelli JLO, Bialetzki A, Shibatta OA
(2016) External Morphology of Lophiosilurus alexandri
Steindachner, 1876 during Early Stages of Development,
and Its Implications for the Evolution of Pseudopimelodidae
(Siluriformes). PLoS ONE 11(4): e0153123. Burgess, W.E., 1989. An atlas of
freshwater and marine catfishes. A preliminary survey
of the Siluriformes. T.F.H. Publications, Inc., Neptune
City, New Jersey (USA). 784 p. Froese, R. and D. Pauly. Editors.
2019. FishBase. World Wide Web electronic publication.
www.fishbase.org, ( 12/2019 ). Oscar A. Shibatta,
Lucas R. Jarduli, Vitor P. Abrahão & Lenice
Souza-Shibatta. (2021). Phylogeny of the
Neotropical Pacman catfish genus Lophiosilurus (Siluriformes:
Pseudopimelodidae). Neotrop. ichthyol., 19 (4).