Systematics, biogeography and conservation of Paragenidens grandoculis n. gen. and n. comb. (Siluriformes; Ariidae), a critically endangered species from southeastern Brazil

Abstract

Paragenidens, a new genus of ariid catfishes is proposed to accommodate Arius grandoculis, a species previously assigned to the genus Potamarius. Paragenidens grandoculis is an endemic ariid catfish categorized as Critically Endangered and probably Extinct from coastal lacustrine systems from Espírito Santo and Rio de Janeiro states, southeastern Brazil. After more than 50 years without records of the species, new recent fieldwork revealed that the species is extinct at lagoa Juparanã, but still can be found at lagoa Nova in Linhares municipality, Espírito Santo state. Here, Paragenidens is described based on morphological and molecular evidence. In addition to its generic reassignment, the species is redescribed, and comments on its phylogenetic relationships, biogeography and conservation are presented.

New clues on the palaeodiversity of the middle Miocene freshwater ichthyofauna from the Tatacoa Desert, Colombia

“…The ancestral form of freshwater catfish Ariidae otolith-based species from the western Amazon included † Cantarius nolfi Aguilera, Moraes-Santos, Costa, Ohe, Jaramillo & Nogueira, 2013b, and † Cantarius ohei Schwarzhans, Aguilera, Scheyer & Carrillo-Briceño, 2022, recorded from the Miocene Pebas wetland system at the Pebas Formation (Carrillo-Briceño et al 2021b; Schwarzhans et al 2022). In North, Central, and South America, six extant ariid species are primarily freshwater, including Chinchaysuyoa labiata Boulenger, 1898, Chinchaysuyoa ortegai Marceniuk, Marchena, Oliveira & Betancur-R, 2019a, Paragenidens grandoculis Steindachner, 1877, Paragenidens nelsoni Evermann & Goldsborough, 1902, Paragenidens izabalensis Hubbs & Miller, 1960, and Paragenidens usumacintae Betancur-R & Willink, 2007 (Marceniuk & Menezes 2007; Marceniuk et al 2019a, b). On the other hand, fossil skull-based species of † Sciades latissimum Aguilera & Marceniuk, 2018, and † Sciades peregrinus Aguilera & Marceniuk, 2018 without preserved internal otolith, were described from the late Miocene Urumaco Fm, Venezuela, characterized by palaeoenvironments associated to a large palaeo-hydrographic system of the Orinoco/Amazonas discharging into the proto-Caribbean Sea (Aguilera et al 2020).…”