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Spatial segregation between Chalceus guaporensis and Chalceus epakros (Osteichthyes: Characiformes) in the Madeira River, Amazon Basin

Authors :
Gislene TORRENTE-VILARA
Ariana CELLA-RIBEIRO
Marília HAUSER
Cristhiana RÖPKE
Maria Helena FREITAS
Carolina Rodrigues da Costa DORIA
Jansen ZUANON
Source :
Acta Amazonica, Vol 48, Iss 3, Pp 239-247 (2018)
Publication Year :
2018
Publisher :
Instituto Nacional de Pesquisas da Amazônia, 2018.

Abstract

ABSTRACT Chalceus guaporensis is an endemic fish to the upper Madeira River whereas C. epakros is widespread in many rivers of the central and lower portions of the Amazon Basin, middle and upper Orinoco River Basin, the Essequibo River in Guyana and in the Nanay River in northern Peru. According to literature, both species do not occur in syntopy. We carried out ichthyological surveys along the Madeira River Basin and its rapids, and data on abundance, diet and habitat use were obtained for both species. Chalceus guaporensis and C. epakros are morphologically similar, occupying floodplain habitats and exploiting similar food resources. The former predominated upstream from the Jirau Fall, whereas the latter had most of its abundance bellow the last fall of the Madeira River; both species co-occurred along part of the rapids stretch and in the Machado River, but with strongly uneven abundances. This pattern may have developed in the past by speciation regarding the presence of the falls, while co-occurrence of the two species seems to be regulated by competitive interactions or maintained by slight differences in environmental requirements nowadays. The recent disruption of the Madeira River by two run-of-river dams built in cascade submerged a large portion of the rapids stretch and substituted it by semi-lenthic habitats created by the dam reservoirs, together with the construction of a fish passage. These environmental changes may allow the invasion of the upper reaches of the Madeira River by C. epakros, and disturb the population of endemic C. guaporensis.

Details

Language :
English, Spanish; Castilian, Portuguese
ISSN :
00445967 and 18094392
Volume :
48
Issue :
3
Database :
Directory of Open Access Journals
Journal :
Acta Amazonica
Publication Type :
Academic Journal
Accession number :
edsdoj.36761bcb49a9838f84804f02ec72
Document Type :
article
Full Text :
https://doi.org/10.1590/1809-4392201703022