(1) John Black (1) Gabriel
Lelis Togni (1)
Body moderately slender, elongate; body depth at anal-fin
origin 17-25% SL; body compressed, width at anal-fin
origin approximately 40% (32-45%) of body depth at
that point. Lateral line complete, midlateral, canal
forms irregular zig-zag pattern, with vertical or
slightly oblique branches extending of angles in canal;
canal bifurcates at caudal fin base; long posteriorly-directed
branches extend from each main branch. Habitat:
Inhabits lower courses of the larger rivers. Free
swimming species found near the surface. Nocturnal,
plus active during dusk and dawn. Occurs less frequently
in flood zones, prefers eroded zones where it appears
in large numbers. Sexual Differences:
The male is recognisable by his thick, ossified maxillary
barbels and by the first few rays of the anal fin
which are fused, supporting the urogenyla tube that
runs along the anterior border to the tip of the rays.
Colouration: Caudal fin with dark
marginal bar. Most specimens with pigmentation on
upper caudal fin lobe distictly darker than on lower
lobe; lower lobe sometimes unpigmented. Diet:
Feeds on smaller fish.
Lower Amazon and Tocantins rivers northward to Marowijne
River; possibly also in Rupununi River, Guyana, and
Negro River, Brazil. Type locality:
Brasilia aequatoriali [now: Rio Capim, near São
Domingos do Capim, Brazil, by neotype designation].
Baensch, H.A. and R.
Riehl, 1985. Aquarien atlas. Band 2. Mergus,
Verlag für Natur-und Heimtierkunde GmbH, Melle,
Germany. 1216 p.
Ferraris, C.J. Jr., 2007. Checklist of catfishes,
recent and fossil (Osteichthyes: Siluriformes), and
catalogue of siluriform primary types. Zootaxa 1418:1-628. Ferraris, C.J. Jr., 2003. Auchenipteridae
(Driftwood catfishes). p. 470-482. In R.E. Reis, S.O.
Kullander and C.J. Ferraris, Jr. (eds.) Checklist
of the Freshwater Fishes of South and Central America.
Porto Alegre: EDIPUCRS, Brasil. Ferraris, J., The South American
catfish genus Auchenipterus Valenciennes, 1840 (Ostariophysi:
Siluriformes: Auchenipteridae): monopoly and relationships,
with a revisionary study. Zoological Journal. Vol.
126, Part 4, 1999. Froese, R. and D. Pauly. Editors.
2021. FishBase. World Wide Web electronic publication.
www.fishbase.org, ( 06/2021 ).