A new genus has been erected,
Rhinotocinclus, (2022) with the type species
of Parotocinclus longirostris Garavello,
1988. Description: Rhinotocinclus
chromodontus is distinguished from congeners,
except R. acuen, R. jumaorum, and
R. dinizae, by having the dominant colour
pattern formed by a dark stripe from the snout tip,
through the eye and extending to end of caudal peduncle
(vs. dominant colour pattern formed by dark bars separated
and distinct, or dark bars wide and partially coalesced
or closed together), and by having a V-shaped light
mark from the snout tip to each nostril (vs. light
mark absent, Y-shaped or present as two separate lines
from snout tip diverging to each nostril). It is also
distinguished from congeners, except R. acuen,
R. hera, R. jumaorum, and R.
dinizae, by lacking an adipose fin or platelets
at the adipose-fin position (vs. adipose fin or platelets
present). Rhinotocinclus chromodontus is
distinguished from R. acuen, R. jumaorum,
and R. dinizae by having the caudal fin mostly
brown, with two hyaline spots on upper and lower lobes
(vs. caudal fin with a dark blotch at base and two
irregular dark bands), and from R. acuen,
R. dinizae, R. hera by having the
oral teeth reddish brown (vs. teeth light ochre).
It is further distinguished from R. acuen,
R. dinizae, R. hera, and R.
jumaorum by the dorsal and pectoral-fin spines
homogeneously dusky (vs. spines with 2–3 dark
& Lehmann 2022).
Found in flat areas in creeks of headwaters of Rio
Tapajós in places of shallow clear waters with
low current and sandy substrate. The holotype of this
species was encountered in a creek severely altered
by human activities; alongside a trail with very shallow
water, the margin deprived of vegetation at the opposite
side of swampy area, where vegetation was mainly represented
by Tipha and Grammineae. Etymology:
Rhinotocinclus masc., from the Greek ????s
(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 chromodontus, From the Greek chroma
(colour), and odontos (tooth), in reference to the
reddish-brown tip of teeth of this species. Remarks:
Most online searches at the moment (2022) will still
give you the old genus name of Hisonotus.
Upper rio Tapajós basin, in the state of Mato
Grosso. Type locality: Brazil: Mato
Grosso State: Diamantino, creek number 1, tributary
of Rio Preto, on road to São Francisco, Rio
Arinos drainage, ca. 14°18’S 56°20’W.
Britski, H.A. and J.C.
Garavello, 2007. Description of two new sympatric
species of the genus Hisonotus Eigenmann and Eigenmann,
1889, from upper Rio Tapajós, Mato Grosso state,
Brazil (Pisces: Ostariophysi: Loricariidae). Brazilian
Journal of Biology. Froese, R. and D. Pauly. Editors.
2022. FishBase. World Wide Web electronic publication.
www.fishbase.org, ( 02/2022 ). 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.