A new species of Copionodon lacking a free orbital rim (Siluriformes: Trichomycteridae)

Abstract

A new species of the copionodontine genus Copionodon is described from the upper reaches of a tributary to the rio Paraguaçu in the Diamantina Plateau, Bahia State, northeastern Brazil. This species represents the northernmost occurrence of the subfamily yet known. The new species can be readily recognized by its large eye without a free orbital rim. Other characters such as the entirely cartilaginous second hypobranchial, and the uniformly broad irregular midlateral dark band further diagnose the new taxon. Its particular combination of characters is superficially intermediate between Copionodon and Glaphyropoma. Detailed analysis, however, indicates that it forms a monophyletic group with species of Copionodon and therefore it should be included in that genus.

Ficha de Copionodon elysium

“…Poças rasas têm acúmulos de detritos de plantas ao longo da margem. A vegetação marginal é típica do "Campo Rupestre", um tipo de vegetação arbustiva herbácea que se desenvolve a elevações de cerca de 900 m sobre arenitos e quartzitos (de Pinna et al, 2018).…”

“…A análise do conteúdo estomacal de três exemplares de Copionodon elysium revelou a presença de itens alóctones e autóctones, compostos principalmente por insetos aquáticos (Trichoptera: larvas de Hydroptilidae e Hydropsychidae; Diptera: larvas de Simuliidae e Chironomidae; coleópteros adultos; ovos de plecópteros), algas filamentosas e fragmentos de insetos terrestres adultos (Hymenoptera: Formicidae), e numerosos grãos de grãos (de Pinna et al, 2018).…”

“…Copionodon elysium tem uma distribuição irregular no riacho, com indivíduos concentrados em certos trechos e totalmente ausentes em outros (de Pinna et al, 2018).…”

Continental fishes from the Tambaba Environmentally Protected Area, Paraíba State, Brazil

“…These authors called attention to the lack of taxonomic data related to the fish fauna for the Atlantic forest in the Brazilian northeast region; Abilhoa et al (2011) recorded 269 freshwater species for streams in this region through data taken from the literature, and Camelier & Zanata (2014) recognized 169 native freshwater species for the northeastern Atlantic Forest ecoregion. Many species were recently described within this region (Barbosa & Costa, 2012;Pereira et al, 2012;Zanata & Pitanga, 2016;Craig et al, 2017;de Pinna et al, 2018;Burger et al, 2019) with achievements of several related studies on the systematics and biogeography of the continental ichthyofauna of the Forest Atlantic.…”