Oligosarcus jacuiensis (Characiformes: Characidae), a new species from the Uruguay and Jacuí River basins, southern Brazil

Abstract

The new species herein described, collected in the Jacuí and Uruguay River basins, Rio Grande do Sul, Brazil, can be distinguished from the already known species of the genus, but Oligosarcus jenynsii, O. perdido, O. acutirostris, O. solitarius and O. hepsetus, by the number of perforated lateral line scales. It shares with the first two species the absence of a premaxillary foramen, present in the last three species and differs from O. jenynsii by having a smaller orbital diameter and the tip of the pectoral fin failing to reach the pelvic-fin origin, and from O. perdido by the presence of more horizontal scale rows around the caudal peduncle.A espécie nova descrita aqui, coletada nas bacias dos rios Jacuí e Uruguai, Rio Grande do Sul, Brasil, pode ser diferenciada das espécies já conhecidas do gênero, com exceção de Oligosarcus jenynsii, O. perdido, O. acutirostris, O. solitarius e O. hepsetus, pelo número de escamas perfuradas ao longo da linha lateral. Compartilha com as duas primeiras espécies a ausência de um forame no premaxilar, presente nas três últimas espécies e difere de O. jenynsii por possuir o diâmetro orbital menor e a extremidade da nadadeira peitoral não alcançando a origem da nadadeira pélvica e de O. perdido pela presença de mais séries horizontais de escamas ao redor do pedúnculo caudal.

Fishes of the Taquari-Antas river basin (Patos Lagoon basin), southern Brazil

“…Non-native Native to North America, this species was intentionally introduced in the 1980s for sport fishing in high elevation streams (Malabarba et al, 2009 Silva, 2004;Rodriguez and Reis, 2008;Carvalho et al, 2008;Carvalho and Reis, 2009;Cognato et al, 2009;Ottoni and Cheffe, 2009;Menezes and Ribeiro, 2010;Ferrer and Malabarba, 2011;Menezes and Weitzman, 2011), but there are few studies and publications on ecology, reproductive biology or conservation (Guadagnin et al, 1998;Majolo, 2005;Alves and Fontoura, 2009;Hirschmann et al, 2008;Luz-Agostinho et al, 2010). The number of species in the Taquari-Antas basin represents ca.…”

Population structure, condition and diet of Oligosarcus paranensis (Menezes & Gery, 1983) (Osteichthyes: Characidae) at two reservoirs in South Brazil

“…The geographic distribution of the characid Oligosarcus is restricted to South America, with seventeen recognized species (Menezes & Ribeiro 2010). They inhabit the headwaters of Andean rivers in Bolivia and Argentina, north of Uruguay and Brazilian territory, where Oligosarcus paranensis is popularly known as 'peixe-cachorro' and is widely distributed in the Upper Paraná River floodplain (Menezes 1988).…”

A new species of the lowland Oligosarcus Günther species group (Teleostei: Ostariophysi: Characidae)

“…The abbreviation SL corresponds to standard length. Comparative material examined is the same of Menezes & Ribeiro (2010). A nearly conical tooth that appears in the species description is characterized by having only a vestigial lateral cusp.…”

“…In addition to Oligosarcus robustus Menezes, 1969, O. jenynsii (Günther, 1864 ), and O. jacuiensis Menezes & Ribeiro, 2010 sympatric species described from the coastal plains of Rio Grande do Sul, Brazil and belonging to the lowland species component of the genus (Menezes, 1988;Ribeiro & Menezes, 2015), another new species was recently discovered from the same area raising to four the number of sympatric species within the rio Jacuí basin, a rather unusual occurrence considering the allopatric distribution of most of the remaining species.…”