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).
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:
The type-locality of R. collinsae was originally
described as “Guyana, Essequibo Province, tributary
to Takutu River about 2 mi from Mazarahally Takutu
lumber camp in Takutu Mountains, approx. 06o15’N
59o05’W, the type specimens being collected
by Robert E. Schmidt and Antonios Pappantoniou on
17 August 1983. Despite the approximate coordinates
provided suggest the locality is in the lower Mazaruni
River, the Takutu River is a well know tributary to
the upper Branco of the Amazon basin. Trying to solve
this apparent inconsistency, we found a collecting
locality of Apistogramma ortmanni at the
AMNH collected by the same collector in 1983 (AMNH
72979; field station RES-83-16) that reads: “Little
Takutu River and tributaries, Mazarahally Takutu lumber
camp, west shore Mazaruni River”. Despite we
could not locate this site precisely on a map, it
names the river as “Little Takutu”, which
differentiates from the Branco tributary Takutu River,
and undoubtedly sets the locality in the lower Mazaruni
basin. For this reason, the original type-locality
of Rhinotocinclus collinsae is herein corrected
to Little Takutu River. Rhinotocinclus collinsae
is currently not assessed by IUCN or other regional
initiative. (Reis
& Lehmann 2022).Further
Remarks: Most online searches at the
moment (2022) will still give you the old genus name
of Parotocinclus collinsae.
Common
Name:
None
Synonyms:
Parotocinclus collinsae
Family:
Loricariidae
Distribution:
Soth America:
Occurs in the Essequibo River basin, including the
Potaro and Mazaruni rivers, in the regions of Cuyuni-Mazarui
and Potaro-Siparuni of Guyana. Type Locality:
Little Takutu River.
Size:
5.0cm. (2ins)
Temp:
23-26°c (73-79°f.)
p.H.
6.5-7.2.
Reference:
Burgess, W.E.,
1989. An atlas of freshwater and marine catfishes.
A preliminary survey of the Siluriformes. T.F.H. Publications,
Inc., Neptune City, New Jersey (USA). 784 p.
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.
Rhinotocinclus
collinsae Female,creek
tributary to Little Takutu River, Cuyuni-Mazaruni, Guyana
Rhinotocinclus
collinsae Dorsal view-Female,
creek tributary to Little Takutu River, Cuyuni-Mazaruni, Guyana.
Rhinotocinclus
collinsae Ventral view-Female,
creek tributary to Little Takutu River, Cuyuni-Mazaruni, Guyana.
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