Description:
Dorsal spines (total): 2; Dorsal soft rays (total):
6 - 6; Anal spines: 4 - 5; Anal soft rays: 8 - 11;
Vertebrae: 41 - 43. Six species of Diplomystidae are
currently recognized (Arratia, 1987; Azpelicueta,
1994a-b). Berra (2001) depicts the family distribution.
Half of the species occur west of the Andes in south
central Chile. The trans-Andean species are D.
chilensis from rivers
near Valparaíso and Santiago,D.
nahuelbutaensis from
the Bío Bío basin, and D. camposensis
from the Valdivia region (Arratia, 1987). Three other
species occur east of the Andes in southern Argentina.
Arratia (1987) erected the genus Olivaichthys
for the Argentinian specimens and Lundberg, et al
(2004) follow Azpelicueta (1994a-b) and most subsequent
authors who treat Olivaichthys as a synonym
of Diplomystes. Habitat:
The cis-Andean species are D. viedmensis
from the Río Negro system, D. cuyanus
from the Río Colorado and the Desaguadero-Salado
basin, and D. mesembrinus known only from
relatively few specimens from Chubut and Senguerr
rivers (Azpelicueta, 1994a-b). Diplomystes
viedmensis has been taken from rivers near sea
level to about 1,900 m (Azpelicueta, 1994a). Diet:
Diplomystids are generalised carnivores that consume
annelids, mollusks, and arthropods (Arratia, 1987;
Azpelicueta & Gosztonyi, 1998). Etymology:
The specific name viedmensis: -ensis, Latin
suffix denoting place: Viedma, Río Negro Province,
Argentina, near type locality.
Common
Name:
Otuno
Synonyms:
Olivaichthys viedmensis
Family:
Diplomystidae
Distribution:
South
America: Negro River and tributaries in Argentina.
Type locality: Río Negro,
Argentina, frente a Viedma.
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