Advanced search
Start date
Betweenand
Related content
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Changes in ichthyofauna composition along a gradient from clearwaters to blackwaters in coastal streams of Atlantic forest (southeastern Brazil) in relation to environmental variables

Full text
Author(s):
Goncalves, Cristina da Silva [1] ; de Souza Braga, Francisco Manoel [1]
Total Authors: 2
Affiliation:
[1] Univ Estadual Paulista Julio de Mesquita Filho UN, Inst Biociencias, Dept Zool, BR-13506900 Rio Claro, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Neotropical Ichthyology; v. 10, n. 3, p. 675-684, JUL-SEP 2012.
Web of Science Citations: 11
Abstract

The lack of knowledge of the freshwater ichthyofauna of coastal streams in the State of São Paulo (Brazil) is a cause of concern, as these streams are inserted in the Atlantic forest, a hotspot highly threatened. The aim of the present study is to investigate the freshwater ichthyofauna composition of clear and blackwater streams in a preservation area of Brazilian Atlantic forest. Fish samples were taken using electrofishing. A total of 20 species were registered, with Astyanax ribeirae, Hollandichthys multifasciatus, and Mimagoniates microlepis (Characiformes, Characidae) as the more representative. In general, the observed pattern of occurrence and distribution of fish species varied according to habitat characteristics, due to the longitudinal gradient in clearwaters, and among clearwaters and blackwaters. In clearwater streams, the headwater stretches had lower species diversity, while the opposite occurred in the middle and lower sites. These longitudinal variations of ichthyofauna were related with habitat characteristics (depth, stream flow, and bottom type) in which they were found, since the diversity of habitats was higher in headwaters and lower in downstream reaches (middle and lower sites). The physical and chemical variables of water do not seem to have influenced the distribution of species in clearwater streams, but the clear and blackwater fish composition was influenced mainly by pH concentration. Unlike the spatial differences, significant temporal differences were not registered in fish assemblages, probably due to the absence of a pronounced dry season in the studied region. (AU)