A new genus has been erected,
Rhinotocinclus, (2022) with the type species
of Parotocinclus longirostris Garavello,
1988. Abstract: A new genus of Hypopopomatinae
armored catfish is described from the northern portions
of South America, namely the Amazon, Orinoco and Guianan
coastal drainages. The new genus is diagnosed from
all remaining hypoptopomatines by having the canal
cheek plate on the ventral surface of the head posteriorly
elongated and contacting the cleithrum, in addition
to other features that distinguish the new genus from
specific genera. Five new species are described and
18 species currently allocated in Parotocinclus,
Hisonotus, and Curculionichthys
are transferred to the new genus and rediagnosed.
Parotocinclus amazonensis and P. aripuanensis
are considered junior synonyms of P. britskii.
The secondary sexual dimorphism of the members of
the new genus is detailed and illustrated. Morphological
characters are used to delimit four phenotypic groups
of species that might have phylogenetic significance,
which still have to be properly tested. A key to the
species is offered and diagnoses, illustrations, and
distribution maps are provided for all species (Reis
& Lehmann 2022).
Description: Rhinotocinclus dani
is distinguished from all congeners, except for R.
bockmanni, R. hera, R. pentakelis,
R. marginalis n. sp., and R. loxochelis
n. sp. by having the dominant colour pattern formed
by five dark bars on body well separated and distinct
(vs. dominant colour pattern formed by four or five
wide dark bars partially coalesced or closed together,
or formed by a dark stripe from the snout tip, through
the eye and extending to end of caudal peduncle);
having two separate light lines from snout tip diverging
to each nostril (vs. light lines on snout absent,
Y- or V-shaped); and by having teeth with yellow (vs.
cusps brown or light ochre). Rhinotocinclus dani
is further distinguished from R. britskii,
R. discolor, R. eppleyi, R.
kwarup, R. isabelae, R. longirostris,
R. pilosus, R. polyochrus, R.
variola, and R. yaka by lacking an adipose
fin (vs. adipose fin present). Rhinotocinclus
dani is further distinguished from congeners,
except R. bockmanni, R. loxochelis
n. sp., R. marginalis n. sp., and R.
pentakelis by having small platelets at adipose-fin
position (vs. small platelets absent). Rhinotocinclus
dani is distinguished from R. bockmanni
by lacking a triangular dark spot at the dorsal-fin
membrane (vs. dorsal-fin dark spot present), and by
having a conspicuous dark bar 2 on body (vs. bar 2
absent or inconspicuous). It is distinguished from
R. hera by having small platelets at adipose-fin
position (vs. small platelets absent) and yellow teeth
cusps (vs. light ochre cusps); and from R. pentakelis
by the shallower body (body depth 16.3–18.3%
vs. 18.4–20.8% SL; caudal peduncle depth 8.8–9.9%
vs. 10.1–11.7% SL; head depth 38.0–43.5%
vs. 43.6–49.5% HL) and shorter dorsal-fin spine
(24.0–27.0% vs. 27.0–30.8% SL). Rhinotocinclus
dani is further distinguished from R. loxochelis
n. sp. by the regularly arranged dark bars on body
(vs. dark bars on body somewhat fragmented and inclined,
such that they connect to form a zig-zag pattern),
the shallower caudal peduncle (8.8–9.9% vs.
10.3–11.2% SL) and smaller orbital diameter
(13.6–16.7% vs. 16.9–18.1% HL); and from
R. marginalis n. sp. by the body dark bars
2 and usually 3 reaching to the ventral midline (vs.
dark bars barely passing lateral dark stripe), and
more numerous premaxillary (19–28, mode 21;
Tab. 1) and dentary (16–22, mode 19; Tab. 2)
teeth (vs. fewer premaxillary, 12–18, mode 16,
and dentary, 11–16, mode 13, teeth) (Reis
& Lehmann 2022).
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 " dani " is in honour of Daniela Fernandes
Roxo, FF Roxo's sister. Remarks:
Most online searches at the moment (2022) will still
give you the old genus name of Parotocinclus dani.
Occurs in the Rio Teles Pires and Rio Jamanxim basins
of the Rio Tapajós drainage, in the states
of Mato Grosso and Pará, Brazil. Type
locality: Municipality of Peixoto de Azevedo,
Mato Grosso State, small tributary of Rio Peixoto
de Azevedo, drainage of Rio Teles Pires, Rio Tapajós
basin, 10°23’10”S 54°18’22”W.
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. Roxo F F, Silva G S C, Oliveira C, pensoft
(2016). Description of a new species of Parotocinclus
(Siluriformes, Hypoptopomatinae) from the rio Tapajos