The ichthyofauna of drifting macrophyte mats in the Ivinhema River, upper Paraná River basin, Brazil

Abstract

We describe the fish assemblages associated with drifting macrophyte mats and consider their possible role as dispersal vectors in the Ivinhema River, a major tributary of the upper Paraná River, Brazil. Fish associated with drifting mats were sampled in the main river channel during January and March 2005, when the wind and/or the increased water level were sufficient to transport macrophyte stands. Fish in the drifting mats were sampled with a floating sieve (4 m long x 2 m wide x 0.6 m high, and 2 mm mesh size). In the laboratory, larvae, juvenile, and adult fish were counted and identified to the lowest possible taxonomic level. In four drifting macrophyte mats we captured 218 individuals belonging to at least 28 species, 17 families, and 6 orders. Aphyocharax dentatus, Serrasalmus spp., and Trachelyopterus galeatus were the most abundant taxa associated with the mats, but species richness ranged from 6 to 24 species per mat. In addition, 85% of the total number of individuals caught was larvae and juveniles. Although preliminary and based on limited samples, this study of drifting macrophyte mats was the first one in the last unregulated stretch of the Paraná River remaining inside Brazilian territory, and alerts us to the potential role of macrophytes mats as dispersers of fish species in the region.Nesse trabalho as assembleias de peixes associadas a bancos de macrófitas flutuantes à deriva foram descritas. Além disso, foi considerado o possível papel desses bancos como vetores de dispersão no rio Ivinhema, importante tributário do alto rio Paraná, Brasil. Os peixes associados aos bancos à deriva foram amostrados no canal principal desse rio, entre os meses de Janeiro a Março de 2005, quando o vento e/ou o aumento no nível da água foram suficientes para transportar os bancos de macrófitas. Os peixes foram amostrados com uma rede flutuante (4 m de comprimento x 2 m de largura x 0,6 m de altura e 2 mm de tamanho de malha). No laboratório, larvas, jovens e adultos foram contados e identificados ao menor nível taxonômico possível. Nos quatro bancos de macrófitas flutuantes a deriva foram capturados 218 indivíduos pertencentes à pelo menos 28 espécies, 17 famílias e 6 ordens. Aphyocharax dentatus, Serrasalmus spp. e Trachelyopterus galeatus foram os táxons mais abundantes associados aos bancos de macrófitas à deriva, mas a riqueza de espécie variou entre 6 e 24 espécies por banco. Além disso, 85% do total do número de indivíduos capturados foram larvas e juvenis. Embora preliminar e baseado em amostragens limitadas, este estudo, conduzido em bancos de macrófitas flutuantes à deriva, foi o primeiro no último trecho não regulado do rio Paraná em território brasileiro, e alerta para o papel potencial que os bancos de macrófitas têm como dispersores de peixes na região.

Assembleias de peixes associadas aos bancos de macrófitas aquáticas em lagos manejados da Amazônia Central, Amazonas, Brasil

“…As assembleias de peixes associadas aos bancos de macrófitas possuem estrutura diferente de acordo com o tipo de estande, como os monoespecíficos de Eichhornia crassipes e E. azurea que podem influenciar a distribuição da ictiofauna (Sánchez-Botero et al 2003). Os peixes também utilizam estes habitats como meio de dispersão (Schiesari et al 2003;Bulla et al 2011), refúgio e berçário (Sánchez-Botero e Araújo-Lima 2001) para os juvenis e espécies de pequeno porte.…”

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

“…Macrophyte beds are fundamentally important for the initial development of many fish species (Delariva et al 1994, Sánchez-Botero & Araújo-Lima 2001, in addition to acting as feeding sites (Casatti et al 2003) and a dispersal mechanism for small-sized species (Oliver & McKaye 1982, Machado-Allison 1990, Bulla et al 2011. The abundance and complexity of macrophyte beds are among the main determinants of fish communities in both lentic (Súarez et al 2001, 2004, Petry et al 2003, Pelicice et al 2005, Gomes et al 2012 and lotic habitats (Bulla et al 2011).…”

Dinámica estacional de la vegetación litoral en el complejo lagunar inundable Zapatosa, Colombia

“…For instance, macroinvertebrates living on macrophytes and in the root zones of floating mats are using this habitat for shelter and food resource, serving also as primary food supply for fish and other vertebrates (primarily amphibians, reptilians and birds; Junk, 1973;Poi de Neiff & Carignan, 1997;Poi de Neiff, 2003;Takeda, Souza-Franco, Melo, & Monkolski, 2003). Furthermore, aquatic vegetation represents a key factor in the selection of habitats by fish (Chick & Mcivor, 1997;Gomes, Bulla, Agostinho, Vasconcelos, & Miranda, 2012), serving as refuge to avoid predators (Chick & Mcivor, 1997;Warfe & Barmuta, 2004), as spawning habitat, and as nurseries for initial life stages and juveniles (Grenouillet & Pond, 2001;Bulla, Gomes, Miranda, & Agostinho, 2011).The 'Zapatosa Floodplain Lake Complex' (ZFLC) and its associated wetlands, part of an even larger floodplain system called the Mompox Depression, is considered one of the most important freshwater ecosystems of the Magdalena River basin in Northern Colombia. in spite of its importance, hydrobiological information on the river basin is practically inexistent, dealing mostly with the local inventory and ecology of fish assemblages (Ríos-Pulgarín, Jiménez-Segura, Palacio, & Ramírez Restrepo, 2008), aquatic and wetland plants (SchmidtMumm, 1987), and a generalized overview on macrophyte vegetation (Rangel-Ch., 2010).…”

“…For instance, macroinvertebrates living on macrophytes and in the root zones of floating mats are using this habitat for shelter and food resource, serving also as primary food supply for fish and other vertebrates (primarily amphibians, reptilians and birds; Junk, 1973;Poi de Neiff & Carignan, 1997;Poi de Neiff, 2003;Takeda, Souza-Franco, Melo, & Monkolski, 2003). Furthermore, aquatic vegetation represents a key factor in the selection of habitats by fish (Chick & Mcivor, 1997;Gomes, Bulla, Agostinho, Vasconcelos, & Miranda, 2012), serving as refuge to avoid predators (Chick & Mcivor, 1997;Warfe & Barmuta, 2004), as spawning habitat, and as nurseries for initial life stages and juveniles (Grenouillet & Pond, 2001;Bulla, Gomes, Miranda, & Agostinho, 2011).…”