This genus is closely related to Hypoptopoma
but has a single line of enlarged odontoded running
along the body just above the lateral line and the
posterior body and the caudal peduncle are flat, whereas
the genus Hypoptopoma has a circular section.
They also posses a narrower head than the species
of Hypoptopoma. Both genera have their eyes
high up on the head. Aquarium Care:
Same care as for Hypotopoma with long leaved
plants or bamboo stalks for them to rest on. Diet:
Algae, vegetables, tablet foodsand
small live and frozen foods. Remarks:
There are at present (2010) three described species
in this genera namely O. carinata (Steindachner,
Ribeiro, 1951 and O.
wrightiana Eigenmann & Eigenmann,
1889 which is the type species.
Middle and upper Amazon River basin. Type
locality: Einem nebenflusse des Amazonenstromes
an der Peruanische Grenze.
Evers, H.-G. &
Baensch Catfish Atlas Volume 1, 1st English edn.,
2005. Pp.944. Ferraris, C.J. Jr., 2007. Checklist
of catfishes, recent and fossil (Osteichthyes: Siluriformes),
and catalogue of siluriform primary types. Zootaxa