Assembléias de peixes associados às macrófitas aquáticas em ambientes alagáveis do Pantanal de Poconé, MT, Brasil

Abstract

Fish assemblages associated to aquatic macrophytes in wetland environments of Pantanal de Poconé, State of Mato Grosso, Brazil. Biota Neotrop. 10(2): http:// www.biotaneotropica.org.br/v10n2/en/abstract?inventory+bn02310022010. Abstract:We examined the composition, richness and biomass of fish assemblages associated with aquatic macrophytes in temporary environments of the Pantanal de Poconé, State of Mato Grosso, Brazil. The fish were captured in April 2008 in five loan boxes and five locations along Coqueiro Bay, using seine nets at three points within each site. A total of 9646 specimens were captured, distributed in seven orders, 17 families and 59 species. The fish community was composed mainly of small-sized species (Characidae) and some juveniles of medium-sized species (Erythrinidae and Gymnotidae). In this study, few species were very abundant, some showed intermediate abundance, and most had low abundance. According to an analysis of similarity (Anosim) there was no difference in species composition between the environments. Species richness, total abundance and biomass did not vary spatially. Thus, the results suggest that the similarity of the fish fauna can be attributed to flooding, since this phenomenon homogenizes the abiotic characteristics and enlarges the area for the distribution of fish. This fact seems to be very important for these small fish species, since many species need to inhabit specific sites during certain stages; for example, these environments may function as temporary refuges. This aspect may ensure the survival of many individuals until they reach a stage in life where predation is significantly reduced. Resumo: Este estudo avaliou a composição, riqueza e a biomassa das assembléias de peixes associadas às macrófitas aquáticas em ambientes temporários do Pantanal de Poconé -MT. A coleta foi realizada em abril de 2008, em cinco caixas de empréstimo e cinco locais na baía do Coqueiro, por meio de rede de cerco, em três pontos dentro de cada local. Foram capturados 9646 exemplares, distribuídos em sete ordens, 17 famílias e 59 espécies. A comunidade de peixes foi composta principalmente por espécies de pequeno porte (Characidae) e alguns juvenis de espécies de médio porte (Erythrinidae e Gymnotidae). Poucas espécies foram muito abundantes, algumas apresentaram abundância intermediária e a maioria apresentou baixa abundância. A análise de similaridade (Anosim) mostrou que não existe diferença na composição de espécies entre os ambientes. A riqueza de espécie e a biomassa dos peixes também não diferiram espacialmente. Desta forma, nossos resultados sugerem que a similaridade da ictiofauna é uma conseqüência da inundação, uma vez que esta permite a homogeneização das características abióticas e amplia a área de distribuição dos peixes. Este fato aparenta ser de grande importância para estes pequenos peixes, considerando que muitas espécies necessitam de lugares específicos em determinados estágios, como, por exemplo, esses ambientes temporários que podem servir de refúgio. Este aspec...

Spatial and temporal variation of fish assemblage associated with aquatic macrophyte patches in the littoral zone of the Ayapel Swamp Complex, Colombia

“…This trend has also been described for areas of the Neotropical floodplain (Araujo-Lima et al, 1986;Milani et al, 2010). The characids' ability to colonize unstable environments and efficiently use the high availability of resources in these biotopes (Willis et al, 2005) explains the numerical importance of this group during the study.…”

Piscivory by Hoplias aff. malabaricus (Bloch, 1794): a question of prey availability?

“…As native predators can decrease Factors such as habitat preference, environmental conditions, prey size and mobility can play a major role on selectivity than prey abundance (Luz- Agostinho et al, 2008;Milani et al, 2010). H. aff.…”

“…malabaricus Bloch, 1794) is a sedentary, opportunistic predator and tolerating several habitats, from open to macrophyte-dominated areas (Milani et al, 2010, Petry et al, 2010. This species has a broad geographic span in the Neotropical region, being virtually present at every hydrographic basin of Brazil, and with at least seven documented subspecies (Petry et al, 2010).…”

“…Several studies on the biology and importance of the "trahira" to the dynamics of Brazilian environments have been conducted, particularly, in the Rio Paraná Basin (Petry et al, 2010;Novakowski et al, 2007;Luz-Agostinho et al, 2008;Peretti and Andrian, 2004), Amazonas (Galacatos et al, 2004) and Pantanal (Milani et al, 2010;Brandão-Gonçalves et al, 2010). Further, experimental studies on its feeding biology and its role on trophic cascades have also been documented Piana et al, 2006).…”

Assemblage of fish species associated with aquatic macrophytes in Porto Murtinho Pantanal, Mato Grosso do Sul, Brazil

“…Some studies have been carried out in the northern Pantanal (Baginski et al 2007, Pacheco & Silva 2009, Fernandes et al 2010, Milani et al 2010, Lourenço et al 2012) and the central region (Súarez et al 2001(Súarez et al , 2004; however few data are available from the southern Pantanal. This study aimed to characterize the composition of fish species associated with aquatic macrophytes in Porto Murtinho Pantanal, near the limit of the Upper Paraguay River.…”