A new genus has been erected,
Rhinotocinclus, (2022) with the type species
of Parotocinclus longirostris Garavello,
1988. Description: Rhinotocinclus
longirostris is distinguished from R. acuen,
R. bockmanni, R. chromodontus, R.
dani, R. dinizae, R. hera,
R. jumaorum, R. pentakelis, R.
marginalis n. sp., and R. loxochelis
n. sp. by possessing an adipose fin (vs. adipose fin
absent), and by having a Y-shaped light mark from
the snout tip to each nostril (vs. light mark V-shaped
or present as two separate lines from snout tip diverging
to each nostril). It is distinguished from R.
collinsae, R. halbolthi, and R.
hardmanni by lacking accessory teeth on both
premaxilla and dentary (vs. accessory teeth present);
the odontodes on the ventral surface of first pelvic-fin
ray bent and pointing mesially (vs. odontodes aligned
with main ray axis,); a triangular dark spot on the
anterior portion of the dorsal-fin membrane (vs. dorsal-fin
spot absent); a Y-shaped light mark from snout tip
to nostrils (vs. light mark absent); and a larger
orbit, 26.7–31.4% snout length (vs. orbit 18.9–24.6%
snout length). Rhinotocinclus longirostris
is distinguished from R. britskii and R.
kwarup, by having the snout more acutely pointed
(vs. snout more broadly rounded, Fig. 11A); dark bars
on body wider and closer together (vs. dark bars on
body narrower and more widely spaced,); and 2–3
plates between the posterior border of the rostral
plate and the nostril (vs. one plate). Rhinotocinclus
longirostris is distinguished from R. variola,
R. yaka, R. discolor n. sp., R.
isabelae n. sp., and R. pilosus n. sp.
by having 4–5 irregular series of middle abdominal
plates (vs. 0–2, rarely 3 irregular series);
and five dark bars on body (vs. four dark bars on
body [bars 1+2 or 2+3 fused], Fig. 7C). It is distinguished
from R. eppleyi by having more numerous premaxillary,
28–36 (mode 30) and dentary, 27–31 (mode
30) teeth (see Tabs. 1–2, vs. fewer premaxillary
(22–30, mode 26) and dentary (21–27, mode
25) teeth) (Reis
& Lehmann 2022).
Habitat: Occurs in tributaries to
the central Amazon, including the Madeira and Negro
basins, in the states of Amazonas, Rondônia,
and Roraima, Brazil. Etymology:
Rhinotocinclus masc., from the Greek (Rhinos),
beak, snout and Otocinclus, a genus of Hypoptopomatinae,
in allusion to the conspicuous and elegant snout of
most of its species. The specific name of longirostris,
points to the long snout of this species. Remarks:
Most online searches at the moment (2022) will still
give you the old genus name of Parotocinclus longirostris.
Rhinotocinclus longirostris, listed as Parotocinclus
longirostris, is currently assessed as Least
Concern (LC) in the Brazilian regional assessment
by ICMBio, (2018) and in the global assessment by
IUCN (Red List).
Amazon River basin. Type locality:
Rio Preto da Eva, Manaus-Itacoatiara highway, km 80,
Manaus, [Amazonas, Brazil].
Froese, R. and D. Pauly.
Editors. 2022. FishBase. World Wide Web electronic
publication. www.fishbase.org, ( 07/2022 ). Reis RE, Lehmann A. P. A new genus
of armored catfish (Siluriformes: Loricariidae) from
the Greater Amazon, with a review of the species and
description of five new species. Neotrop Ichthyol.
2022. Schaefer, S.A. and F. Provenzano,
1993. The Guyana Shield Parotocinclus: systematic,
biogeography, and description of a new Venezuelan
species (Siluroidei: Loricariidae). Ichthyol. Explor.