A new species of Curculionichthys (Siluriformes: Loricariidae) from the north edge of the Brazilian Shield, lower Amazon basin

Abstract

A new species of Curculionichthys is described from the rio Curuá-Una basin, in the northern edge of the Brazilian Shield, State of Pará, Brazil. The new species is diagnosed from congeners by possessing a single rostral plate, by having darkened tooth-crowns, and by a series of morphometric and meristic data. A close examination of the species of Curculionichthys revealed the presence of hyperthrophied odontodes on both dorsal and ventral margins of the snout tip, which are illustrated by electronic microscopy. A discussion is provided on possible phylogenetic relationships of the new taxon. The new species is provisionally accessed as Least Concern (not threatened).

On a remarkable sexual dimorphic trait in the Characiformes related to the olfactory organ and description of a new miniature species of Tyttobrycon Géry (Characiformes: Characidae)

“…In this type of dimorphism, the olfactory organs of mature males can be very large with many lamellae, which contrast with smaller organ and with fewer lamellae in females. Among ostariophysans, secondary sexual dimorphism linked to the olfactory organ has been reported in Siluriformes [50–53]. Male catfishes of some species of Loricariidae may exhibit a more developed olfactory organ, higher number and different shape of the lamellae ( Chauliocheilos saxatilis Martins, Andrade, Rosa & Langeani), and also wider nostrils than females ( Microlepidogaster dimorpha Martins & Langeani; Parotocinclus fluminense Roxo, Melo, Silva & Oliveira; Curculionichthys hera Gamarra, Calegari & Reis).…”

“…g . [51,53]). However, finding a potential mate is not a major problem for Neotropical characid fishes since they commonly form schools ( e .…”

Ontogeny of the brain of Microglanis garavelloi Shibatta and Benine 2005 (Teleostei: Siluriformes: Pseudopimelodidae)

“…The addition of olfactory lamellae results from growth only and is not sexually dimorphic. Curiously, sexual dimorphism in the peripheral olfactory organ related to the number of lamellae and size of the narial opening has been reported in several Teleostei groups (e.g., Abrahão et al, 2019; Bertelsen, 1951, 1980, 1987; Caruso, 1975; Gamarra et al, 2019; Marshall, 1967), including some Siluriformes (Martins et al, 2014; Martins & Langeani, 2011; Roxo et al, 2017). Notwithstanding, some teleosts continuously add lamellae to the olfactory organ in both sexes, and well‐developed organs can reach up to hundreds of lamellae (Abrahão et al, 2019; Angulo & Langeani, 2017; Hansen & Zeiske, 1993; Pfeiffer, 1964).…”

A new species ofParotocinclus(Loricariidae: Hypoptopomatinae) from the rio Pardo basin, Bahia State, Brazil, with comments on the sexually dimorphic traits of the nares and olfactory lamellae

“…However, detailed studies are needed to better evaluate the ontogenetic variation of the number of lamellae within males and females of hypoptopomatines. Current discussions about possible functions of Regan, 1926), particularly in species living in dark environments or with nocturnal activity (Gamarra et al, 2019;Sazima, 1986).…”

“…olfactory lamellae is still restrict to a few recent studies and have been observed in members of Characiformes and Siluriformes(Abrahão et al, 2019;Gamarra et al, 2019;Martins et al, 2014;Martins & Langeani, 2011;Roxo et al, 2017). Particularly within Loricariidae, especially hypoptopomatines, males with wider nares than females were reported in Curculionichthys hera Gamarra, Calegari & Reis, Microlepidogaster dimorpha Martins & Langeani and Parotocinclus fluminense Roxo, Melo, Silva & Oliveira, where it was described for the latter as an 'apparent dimorphic feature' (Gamarra et al, 2019; Martins & Langeani, 2011; Roxo et al, 2017).…”