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 kwarup,
from the upper Rio Xingu basin, is most similar to
R. bristkii. The morphological differences
found between these two species are the colour pattern,
which has more broken marks, creating a mottled appearance
in the former, while R. britskii has the
body bars and head marks more unbroken, causing a
clearer pattern, and the number of oral teeth, as
R. kwarup has 28–34 (mode 32) premaxillary
and 27–33 (mode 29) dentary teeth, while all
analyzed populations of R. britskii have
15–29 (mode 23) premaxillary and 15–29
(mode 20 and 25) dentary teeth, see Tabs. 1 and 2
for tooth count distribution. These counts are not
fully discrete and partially overlap, and this species
should probably be included in a wide molecular assessment
of P. britskii populations. Rhinotocinclus
kwarup was tentatively categorized as Least Concern
(LC) by Lehmann, Reis, (2021) in the original description.
& 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. Remarks:
Most online searches at the moment (2022) will still
give you the old genus name of Parotocinclus kwarup.
In the tributaries of the upper Rio Xingu in the state
of Mato Grosso, Brazil. Type Locality:
Couto de Magalhães River near Vila São
José do Couto, Campinápolis, MT, Brazil
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.