Description:
Homodiaetus is currently distinguished from
other genera of Stegophilinae by the combination of
the origin of the pelvic fin midlength between the
tip of the snout and the caudal-fin origin, the opercle
with three or more odontodes, and the gill membranes
confluent with the isthmus. Homodiaetus species
are small and grow up to 42 millimetres (1.7 in) SL.
They are transparent with the except of the head and
abdomen. They have a thin body and depressed head
that is almost as wide as the head is long. The dorsal
and ventral profiles are straight except for a convex
head. The mouth is inferior. Among the other three
species, H. graciosa has 5–6 rows of
teeth in the dentary (vs. 6–7 in the other two
species). H. graciosa has 7–9 (usually
8) opercular odontodes, H. passarellii has
6–7, and H. banguella has 9.
Colouration:H. anisitsi
has three dark bands on its caudal fin, while dark
lines are irregular or absent in the other three species.
Habitat:
The distribution of Homodiaetus is restricted
to the southeastern South America, from Uruguay to
Paraguay Rivers in the west to the coastal drainages
of the Rio de Janeiro State, Brazil. H. anisitsi
originates from the Paraná-Paraguay River basin.
H. banguela inhabits the São João
River and H. passarellii is known from coastal
basins in the State of Rio de Janeiro. H. graciosa
is distributed in coastal basins of southeastern Brazil
in states of Paraná and São Paulo. Etymology:
The genus name of Homodiaetus:
according to Eigenmann (1922),
“living or eating with others” (homos,
same; diaeta, manner of living or diet), referring
to the “known parasitic habits of some of its
relatives”. The specific name of anisitsi:
in honour of Juan Daniel Anisits (1856-1911), National
University of Paraguay, who provided Indiana University
with a “well-preserved” collection of
fishes, including type of this one. Remarks:
These fish are known to be lepidophagous, meaning
they feed upon the scales of other fish. Homodiaetus
anisitsi is the
type species.
Common
Name:
None
Synonyms:
Homodiaetus vazferreirai
Family:
Trichomycteridae
Distribution:
South America:Paraná-Paraguay River basin (Argentina,
Brazil, Paraguay and Uruguay. Type locality:
Small creek at Villa Rica, Paraguay.
Homodiaetus
anisitsi Dorsal view-Rosario, Santa Fe, Argentina
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