info:eu-repo/semantics/article
Fish ecology of a seasonal lowland stream in temperate South America
Fecha
2000-01Registro en:
Almirón, Adriana Edith; Garcia, Mirta Lidia; Menni, Roberto Carlos; Protogino, Lucila Cristina; Solari, Lía Cristina; Fish ecology of a seasonal lowland stream in temperate South America; Csiro Publishing; Marine and Freshwater Research; 51; 3; 1-2000; 265-274
1323-1650
CONICET Digital
CONICET
Autor
Almirón, Adriana Edith
Garcia, Mirta Lidia
Menni, Roberto Carlos
Protogino, Lucila Cristina
Solari, Lía Cristina
Resumen
El Pescado (literally ‘the fish’) is a lowland stream in the pampean plain, entering the Rio de La Plata at 35˚55¢S,57˚45¢W, 70 km SW of the city of Buenos Aires. The stream develops as a potamon with variable flood frequency along its 36 km length. The water is slightly soft, with relatively high conductivity and dominance of HCO–3 , Na + and Cl – ions. Three fish families, Characidae (29%), Pimelodidae (14.6%) and Loricariidae (12.8%) are most abundant among 55 species. Differences in species composition among four stations with different environmental traits were observed. Flooding slightly affected the fish fauna. In open-water and rocky-bottom stations, both species number and number of individuals were correlated with conductivity, an indication of the decrease of fish density with floods. Species richness was well over worldwide means. Diversity values, higher than in small tropical streams in Venezuela and southern Brazil, ranged from 0.32 to 2.59, being higher during autumn and spring. The stream has a high persistence, with the composition of the fish community maintained or recovering as soon as flooding ends. One Synbranchus marmoratus specimen was found among rocks, the first record of this behaviour for the species.