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 jumaorum was also described
as a member of Hisonotus by Dias et al.,
(2018), disregarding the study of Calegari et al.,
(2017) which redefined Hisonotus and restricted
its distribution to the La Plata basin and coastal
rivers from Uruguay to Espirito Santo State, Brazil.
For this reason, and based on the fact that Hisonotus
jumaorum shares some diagnostic features of Curculionichthys
and is distributed in Amazon tributaries running on
the Brazilian Shield, Calegari et al., (2018) reallocated
the species as Curculionichthys jumaorum.
Roxo et al., (2019), however, transfered the species
back to Hisonotus. Extintion risk of Rhinotocinclus
jumaorum is currently not assessed (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. Remarks:
Some online searches at the moment (2022) will still
give you the old genus names of Hisonotus jumaorum
or Curculionichthys jumaorum.
Hisonotus jumaorum, Curculionichthys
Occurs in the Rio Juma, a small tributary to the Rio
Aripuanã and the Rio Acari, a tributary to
the rio Canumã, Rio Madeira basin, in state
of Amazonas, 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.