Habitat use by Astyanax taeniatus (Jenyns, 1842) (Characiformes: Characidae) in a coastal stream from Southeast Brazil

Carla Ferreira Rezende,Luisa Resende Manna,Rosana Mazzoni

doi:10.1590/s1679-62252014000100020

Carla Ferreira Rezende, Luisa Resende Manna + Show 1 more

Open Access

https://doi.org/10.1590/s1679-62252014000100020

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Abstract

The habitat use of a stream-dwelling Astyanax taeniatus from the State of Rio de Janeiro was investigated. We performed 12 h of underwater observation in a 200 m long stretch in the upper Roncador stream and quantified the following microhabitat descriptors: (i) water velocity, (ii) distance from the stream bank, (iii) substratum, and (iv) water column depth. Microhabitat selectivity was analyzed by comparing the microhabitat used by fish and the microhabitat available in the study site as well as by applying the Ivlev Electivity Index to the microhabitat use data. Differences in the use and availability of the various microhabitats revealed non-stochastic patterns of spatial occupation by A. taeniatus, which was selective for two of the four analyzed microhabitats. Our findings indicated that A. taeniatusis associated with habitats that have higher depths, low water velocity, and sand and bedrock substratum.

Highlights

The spatial segregation of individuals due to differences in resource use is an important aspect of population and community structure (Ross, 1986; Arlettaz, 1999)
The use of habitats by fish can be related to many lifehistory features, including morphology (Wootton, 1998), reproductive requirements (Munro, 1990) and body size (Davey et al, 2005; Beyer et al, 2007)
A. janeiroensis segregated along a coastal stream in response to reproductive requirements, and only adult individuals were found in the upstream stretches of the studied area (Mazzoni et al, 2004)

Summary

Introduction

The spatial segregation of individuals due to differences in resource use is an important aspect of population and community structure (Ross, 1986; Arlettaz, 1999). Fish species have specific patterns of habitat use and feeding and reproductive strategies that allow only a few species to occupy the same space (Weatherley, 1963), and these species segregate in the available space (Roff, 1992). The mesohabitat represents large-scale physical units determined by the presence of riffles, runs, and pools (Angermeier & Schlosser, 1989), and the most important differences between these units are related to water velocity and substratum. The microhabitat represents specific subunits of the mesohabitats with specific physical structural components (Sedell et al, 1990). Heterogeneous environments provide a greater variety of microhabitats with protected places where fish can shelter themselves from predators and where they can find a wide range of food resources and sites for reproduction (Wootton, 1998)

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