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Reis & Lehmann 2022 (3)

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 acuen was also described as a member of Hisonotus, and accordingly compared to other species of the later genus (Silva et al., 2014). Interestingly, in the diagnosis of the new species the authors begin saying “Hisonotus acuen differs from all congeners except H. bockmanni, H. chromodontus, H. insperatus, H. luteofrenatus, H. oliveirai, and H. paresi by having a functional V-shaped spinelet”. Both H. bockmanni and H. chromodontus are herein being tranferred to Rhinotocinclus and the remaining species have already been transferred to Curculionichthys, the functional V-shaped spinelet indeed diagnosing R. acuen and, in fact, all Rhinotocinclus and Curculionichthys species, from Hisonotus. Extintion risk of Rhinotocinclus acuen 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: Most online searches at the moment (2022) will still give you the old genus name of Hisonotus acuen.

None

Hisonotus acuen

Loricariidae

Soth America: Upper Xingu River basin, Mato Grosso, Brazil. Type locality: Brazil, Mato Grosso State, municipality of Querência, affluent of Rio Toguro, Rio Xingu basin, 13°00’26”S 52°11’27”W.

2.5cm. (1ins)

24-27°c (75-81°f.)

5.5-6.5.

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.