Estudo taxonômico da ictiofauna de água doce da bacia do Recôncavo Sul, Bahia, Brasil

Abstract

Abstract:The Recôncavo Sul basin is a portion of the coastal river drainages of Eastern Brazil almost entirely included in the "Baixo Sul" region of Bahia State, and is limited at its northern and northwestern borders by the rio Paraguaçu basin and at its southern and southwestern borders by the rio de Contas basin. In this study a total of 41 strictly freshwater fish species were recorded, belonging to 28 genera, 12 families, and six orders (18 Characiformes, 13 Siluriformes, five Perciformes, two Cyprinodontiformes, two Gymnotiformes, and one Synbranchiformes). Ten possibly undescribed, four endemic, and four introduced species were recorded in the area of study. One species occurring in the area is considered threatened with extinction. An identification key to the species known for the Recôncavo Sul is provided, as well as comments about the taxonomy and distribution of some species. Due to its comparatively high diversity and relatively pristine condition the rio das Almas drainage is suggested as a key area for conservation. Resumo: A bacia do Recôncavo Sul faz parte das drenagens costeiras do Leste do Brasil, está quase inteiramente incluída na região do Baixo Sul do Estado da Bahia, é limitada ao norte e noroeste pela bacia do rio Paraguaçu e ao sul e sudoeste pelo rio de Contas. No presente estudo, um total de 41 espécies de peixes estritamente de água doce foi registrado, pertencentes a 28 gêneros, 12 famílias e seis ordens (18 Characiformes, 13 Siluriformes, cinco Perciformes, duas Cyprinodontiformes, duas Gymnotiformes e uma Synbranchiformes). Foram encontradas dez espécies possivelmente ainda não descritas, quatro espécies endêmicas e quatro introduzidas na área de estudo. Uma espécie presente na área está ameaçada de extinção. Uma chave de identificação para as espécies conhecidas para o Recôncavo Sul é apresentada, assim como comentários sobre a taxonomia e distribuição de algumas espécies. Devido à diversidade comparativamente alta e condições ambientais relativamente preservadas, a bacia do rio das Almas é indicada como uma área chave para conservação. Palavras-chave: inventário, peixes de água doce, Nordeste do Brasil, bacia do Leste, Baixo Sul.

A new species of Characidium (Characiformes: Crenuchidae) from small coastal drainages in northeastern Brazil, with remarks on the pseudotympanum of some species of the genus

“…bimaculatum, and C. aff. timbuiense, e.g., Santos & Caramaschi, 2007Sarmento-Soares et al, 2008Cetra et al, 2010;Burger et al, 2011). These tentative identifications are actually indicative of the current poor taxonomical knowledge about the Characidium species in that region, which very likely, harbors several undescribed species of the genus.…”

“…timbuiense and C. aff. zebra (e.g., Burger et al, 2011;Cetra et al, 2011), attesting to the taxonomic difficulties regarding the identification of species in the genus. Collecting efforts performed in the last eight years in the costal drainages of Bahia have revealed various undescribed species of Characidium, including one described in the present study, apparently endemic to the small drainages of rio das Almas and rio Vermelho.…”

Molecular phylogeny and biogeographic history of the Neotropical tribe Glandulocaudini (Characiformes: Characidae: Stevardiinae)

“…According to Menezes et al (2008) and Menezes, Weitzman (2009), the northernmost limit of distribution of Glandulocaudini is around the city of Prado, in the southern part of the Bahia State, at the type locality of M. sylvicola. However, this species also occurs in some small coastal drainages of the Recôncavo Sul basin (Burger et al, 2011) in addition to the Pardo, Paraguaçu, and Real river basins (Camelier, Zanata, 2014;present study, MZUSP 112657, 112679, 115092, UFBA 7004), located in the Bahia State, but to the north of the Prado region. The rio Real basin is the boundary between Bahia and Sergipe States and it becomes the northernmost limit of the distribution of both M. sylvicola and the tribe Glandulocaudini (Fig.…”

First records of Cheirodontinae (Actinopterygii: Characiformes: Characidae) from drainages of Espírito Santo state, southeastern Brazil

“…New records of this species were recently reported from Recôncavo Sul (southern Recôncavo region) coastal drainages in Bahia state (Burger et al 2011) and the middle Rio Doce basin in Minas Gerais state (Vieira 2009). In both cases, previous authors considered the occurrence as a natural event.…”