Benthic invertebrates and the habitat structure in an intermittent river of the semi-arid region of Brazil

• Published in: Neotropical biology and conservation Vol. 8; no. 2; p. 57
• Main Authors: Laryssa Kalliane Carvalho, Rafaela Lima Farias, Elvio Sergio Figueredo Medeiros
• Format: Journal Article
• Language: English
• Published: Sophia Pensoft Publishers 01-05-2013
• ISSN: 1809-9939; 2236-3777

Interactions between the habitat structure and physical and chemical parameters generate environmental conditions that influence the distribution and abundance of macroinvertebrate species and their assemblages. This study describes the habitat structure and its effects on macroinvertebrate composition in an intermittent stream in the Brazilian semi-arid. Collections of benthic invertebrates were performed in three reaches along the Ipanema River during the dry and wet seasons using a "D" shaped net (40 cm wide and 250 μm mesh). A total of 23 taxa was recorded, Insecta being the most representative with 12 families and an average density of 168.1 ind/m². Correlations between environmental variables and CCA axes showed that substrate composition (sand and mud), macrophytes, litter and altitude were the main variables explaining benthic macroinvertebrate composition in the study stream. Canonical correlations between macroinvertebrate and physical and chemical variables were not significant. This study shows that the habitat structure contributes to the persistence and stability of macroinvertebrate communities in a Brazilian semi-arid stream, by creating refugia for organisms and contributing to the physical structures available for colonization.