The combination of the absence of a spinelet associated
with the dorsal fin, the absence of spines on the
dorsal and pectoral fins, and the possession of a
single row of teeth on the vomer distinguishes Cetopsis
from the other genera in the Cetopsinae. Habitat:
It inhabits streams with moderate current and a depth
of up to 1 m, occurring within such streams in areas
over sand substrates but lacking vegetation. Sexual
males of Cetopsis plumbea have a distal filament
on the first ray of the dorsal fin. That filament
is absent in females and immature males of the species.
Mature males also have the filament on the first pectoral-fin
ray proportionally more elongate than the extension
of the ray present in conspecific females and immature
males. Mature males have an anal-fin margin that is
distinctly convex contrary to the straight anal-fin
margin that is characteristic of females and immature
males of the species. Diet: Feeds
on a variety of terrestrial and aquatic insects.
Upper Amazon River basin, Ecuador and Peru. Type
locality: Canelos (Ecuador).
22-28°c (71-83°f )
Ferraris, C.J. Jr.,
2007. Checklist of catfishes, recent and fossil (Osteichthyes:
Siluriformes), and catalogue of siluriform primary
types. Zootaxa 1418:1-628. Vari, R. P., C. J. Ferraris Jr. & M. C.
C. de Pinna. 2005. The Neotropical whale
catfishes (Siluriformes: Cetopsidae: Cetopsinae),
a revisionary study. Neotropical Ichthyology 3:127-238.