Rhyacoglanis annulatus
is known solely from the southern portions of the
Río Orinoco basin in Venezuela. Rhyacoglanis,
a new genus of the South American freshwater catfish
family Pseudopimelodidae is described from cis-Andean
portions of the continent. Rhyacoglanis is
distinguished from other genera of the family by three
synapomorphies: presence of a light blotch on the
cheek; a connection between the middle of the dark
caudal-fin stripe and the dark caudal-peduncle pigmentation;
and 30-35 total vertebrae. Species of Rhyacoglanis
are rheophilic and strongly associated with rapids
and other swift-flowing waters. A phylogenetic analysis
based on 41 morphological characters yields a hypothesis
of monophyly of the Pseudopimelodidae and Rhyacoglanis.
Pimelodus pulcher Boulenger, 1887, from the
western Amazon basin is designated as type-species
of the new genus and redescribed. Four new species
are described: Rhyacoglanis
annulatus, from
the río Orinoco basin, with a nearly ringed
dark band on the caudal peduncle, and a larger distance
between anus and anal-fin origin; R. epiblepsis,
from the rio Madeira basin, with numerous dark spots
scattered on the body, and rounded caudal-fin lobes;
R.
paranensis from the upper rio Paraná
basin, with three distinct dark bands on the body,
and 31-33 total vertebrae; and R. seminiger,
from the rio Juruena basin, with subdorsal and subadipose
dark bands fused anteroposteriorly, and a separate
dark band on the caudal peduncle. Aquarium
Care: Predatory in the aquarium towards fish
that are smaller. Provide plenty of hiding places
to hide during the day and best kept in a small group
of 2-3. Very secretive in its surroundings.
Diet: No problem with eating all types of
aquarium fare, flake, tablets, pellets, live and frozen
foods.
Common
Name:
None
Synonyms:
None
Family:
Pseudopimelodidae
Distribution:
South America: Río
Orinoco basin, Venezuela. Type locality:
río Orinoco basin, río Ventuari,
exposed cobble beach along base of Cerro Moriche,
about 1 km upstream of Moriche community, 167 km E-NE
of San Fernando de Atabapo, 04o45’12.46”N
66o22’21”W
Size:
6.0cm. (2½ins)
Temp:
24-28°C (75-83°F)
p.H.
6.0-7.5.
Reference:
Shibatta, Oscar Akio,
& Vari, Richard P. (2017). A new genus
of Neotropical rheophilic catfishes, with four new
species (Teleostei: Siluriformes: Pseudopimelodidae).
Neotropical Ichthyology, 15(2), e160132. Epub June
12, 2017.https://dx.doi.org/10.1590/1982-0224-20160132
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