Composição da ictiofauna em função da fisiografia de um riacho costeiro de Floresta Atlântica - Brasil

Abstract

Abstract:In spite of the impacts that tropical streams are submitted, they still present a great fish diversity. The knowledge of the fish structure and composition is an important attempt in order to stabilish evaluation parameters that can favour conservation of these environments. The icthyofaunal composition related to physiographic features of coastal streams of south Brazil is an important contribution to the interpretation of these ecosystem dynamics. We perform fish collections in five sampling sites in the Pinto River, placed in Morretes municipality in the Paraná State, Brazil. The samples were accomplished between May 2006 and November 2007, using electric fishing along 50 m/hour in each site. The collected animals were fixed in formaline 10%. Each site (point) was classified in relation to the bottom substratum, depth, width average, and current speed. Direct relationship between substratum type and fish compostition was observed. Siluriformes were predominant in places with coarseness granulometry, such as boulders, cobbles and pebbles. On the other hand, Characiformes were predominant in places with smaller granulometry, such as coarse sand and gravel. Resumo: Os riachos costeiros apresentam grande diversidade de peixes, apesar dos impactos a que são submetidos. O conhecimento da estrutura e da composição da ictiofauna constitui importante esforço para levantamento de parâmetros de avaliação que possam proporcionar atitudes para a conservação destes ambientes. A composição da ictiofauna relacionada a características fisiográficas de riachos costeiros do sul do Brasil constitui-se uma contribuição para a interpretação da dinâmica destes ecossistemas. Foram realizadas coletas de peixes em cinco pontos amostrais do Rio do Pinto, localizado no município de Morretes, Paraná, Brasil. As coletas foram realizadas entre os meses de maio de 2006 a novembro de 2007, utilizando a técnica de pesca elétrica, com um esforço amostral de 50 m/hora em cada localidade. Os animais coletados foram fixados em formaldeído 10%. Cada localidade foi classificada em relação ao tipo de substrato, profundidade, velocidade de correnteza e largura média. Foi possível observar a relação direta entre o tipo de substrato e a composição da ictiofauna. Em regiões onde a granulometria era maior, tais como matacões e seixos, prevaleceram os Siluriformes. Por outro lado, em regiões onde o sedimento apresentava menor granulometria, tais como areia grossa associada a cascalho, ocorreram espécies de Characiformes.

Ichthyofauna from the Parque Nacional da Serra dos Órgãos and its surrounding areas, Rio de Janeiro state, Brazil

“…The Atlantic Rain Forest has a rich ichthyofauna, estimated about 270 species, belonging to 89 genera and 21 families (Abilhoa et al 2011;Miranda 2012). However, there are several doubts on species descriptions and on the ecological processes such as heavy water turmoil and vegetation influences on fish assemblages (Guimarães et al 2010). Despite the high biodiversity in the Atlantic Rain Forest, anthropogenic activities have jeopardized this system and there are few studies on streams fish composition and structure (Myers et al 2000;Miranda 2012).…”

Checklist of freshwater ichthyofauna from coastal streams of Juréia-Itatins reserve, southeastern Brazil

“…The family Characidae was predominant ( Figure 5), mainly due to the abundance of Astyanax ribeirae, Mimagoniates microlepis, and Hollandichthys multifasciatus. The freshwater fish fauna in the sampled streams in JIES is similar to other Brazilian coastal basins, with the predominance of Characiformes and/or Siluriformes (Sabino and Castro 1990;Mazzoni and Lobón-Cerviá 2000;Esteves and Lobón-Cerviá 2001;Uieda and Uieda 2001;Gerhard et al 2004;Serra et al 2007;Ferreira and Petrere Jr. 2009;Guimarães et al 2010;Mattox and Iglesias 2010), and confirms with what is expected in freshwater environments included in the studied region (Lévêque et al 2008). The representation of the Characidae species was also expected, since this family is one of the most species-rich in the Neotropical region (Reis et al 2003).…”

“…In addition, the occurrence of marine-estuarine species in coastal streams decreases as the distance from the estuary increases (Leung and Camargo 2005). Nevertheless, A. tajasica was found in distant reaches with little or no marine influence in two streams at JIES, as recorded by Uieda and Uieda (2001), Sabino and Silva (2004), and Guimarães et al (2010) in other Brazilian coastal streams. …”

Fish habitat associations along a longitudinal gradient in a preserved coastal Atlantic stream, Brazil

“…Based on the literature, between 20 and 50 fish species are estimated to occur in coastal Atlantic streams of Paraná state (Fogaça et al 2003, Barreto and Aranha 2005, Abilhoa and Bastos 2009, Guimarães et al 2010. Channels located on steep slopes of the Serra do Mar mountains and geographical isolation due the subdivision of eastern Atlantic basin in several sub basins, have conferred to fish smaller sizes and higher degree of endemism (Vari andMalabarba 1998, Menezes et al 2007).…”

“…Ancistrus multispinnis inhabits moderate to fast currents dwelling on boulders and cobbles (Barreto and Aranha 2005) and presents larger ventral sucker mouth than other loricariids, which allows it to adhere to the substratum (Breda et al 2005). A congeneric of R. frenatus, Rhamdioglanis transfaciatus Miranda Ribeiro, 1908 with (Guimarães et al 2010), indicating the capacities of these species of swimming among boulders and cobbles. The DCA and statistical tests showed that fish community structure differed only between upper and mouth reaches.…”