Spatial and temporal variations of the fish assemblage of a low order fluvial system from central-south of Chile Variaciones espacio-temporales del ensamble de peces de un sistema fluvial de bajo orden del centro-sur de Chile

Habit, E.; Victoriano P.; Rodriguez-Ruiz, A

Keywords: nothofagus, salmonidae, pisces

Abstract

The Nonguén stream (order 3) is a lower zone tributary of the Andalién river coastal mountain basin (Bio-Bío region) which displays a marked difference between its rithral sector (well-conserved and with a secondary Nothofagus forest) and its potamal area (urbanly-used and organically polluted waters). This contrast could imply an alteration in the normal pattern of Chilean ichthyofauna, as described for a variety of fluvial systems in the country: a downstream increase in numbers of species, individuals, and diversity downstream, as well as increased corporal sizes of individuals in the lower zones of the river. Species composition of fishes of the Nonguén stream and their community patterns along the fluvial system within an annual cycle have been studied. The results show a high number of species in the lower parts, i.e. four species in the rithron and ten in the river mouth. The diversity, abundance and distribution of the fishes varied according to the season of the year, reflecting displacements associated with the fauna' s ontogeny, reproduction and feeding. The sampling stations of the middle and lower zones of the river presented an assemblage with smaller individuals than those found at the head of the river, with the consistent dominance of larger salmonidae in the upper zone. Accordingly, it is suggested that: (i) the alteration of the potamal area does not significantly modify the characteristic patterns of ichthyofauna in fluvial systems, and (ii) the Nonguén stream is a reproduction and growth system for juveniles of both native and introduced species which make up permanent associations in the fluvial system.

Más información

Título según SCOPUS: Spatial and temporal variations of the fish assemblage of a low order fluvial system from central-south of Chile [Variaciones espacio-temporales del ensamble de peces de un sistema fluvial de bajo orden del centro-sur de Chile]
Título de la Revista: Revista chilena de historia natural
Volumen: 76
Número: 1
Editorial: Sociedad de Biología de Chile
Fecha de publicación: 2003
Página de inicio: 3
Página final: 14
Idioma: Spanish
URL: http://www.scopus.com/inward/record.url?eid=2-s2.0-0038471267&partnerID=q2rCbXpz
Notas: SCOPUS