Fishes of the upper Rio Negro, Bolivian Amazon: Community composition and ecological and biogeographical considerations

Authors
Citation
Ca. Lasso, Fishes of the upper Rio Negro, Bolivian Amazon: Community composition and ecological and biogeographical considerations, INTERCIENCI, 26(6), 2001, pp. 236
Citations number
20
Language
SPAGNOLO
art.tipo
Article
Categorie Soggetti
Multidisciplinary
Journal title
INTERCIENCIA
ISSN journal
0378-1844 → ACNP
Volume
26
Issue
6
Year of publication
2001
Database
ISI
SICI code
0378-1844(200106)26:6<236:FOTURN>2.0.ZU;2-8
Abstract
A study was made of the fish communities of the upper Rio Negro, Department of Santa Cruz, Bolivia, during the dry season of 1993. Fifty-eight species were identified, of which 33 were new to the Rio Negro, and give the total drainage a documented diversity of 108 species: Myliobatiformes (1 species ), Characiformes (50), Gymnotiformes (5), Siluriformes (43), Synbranchiform es (1) and Perciformes (8). The families Characidae and Loricariidae were t he most diverse (36 and 18 species, respectively). The ichthyological simil arity between the two sections of the drainage (upper and lower) was very l ow (Simpson index = 33%), indicating the presence of two well-differenciate d fish faunas. The most abundant species were Pimelodella sp, Ancistrus spl , Moenkhausia dichroura, Eigenmannia virescens, Ancistrus sp2 and Crenicich la cf lepidota. Relative biomass was estimated to be 38g/m(2) with a fish d ensity of 4 fish/m(2). The ecological diversity (Shannon index) varied betw een 1.14 and 2.46 bits. Equity was not high.