BENTHIC INSECTS OF THE EL TALA RIVER (CATAMARCA, ARGENTINA): LONGITUDINAL VARIATION OF THEIR STRUCTURE AND USE OF INSECTS TO ASSES WATER QUALITY

COLLA, MARIA FLORENCIA; CÉSAR, INÉS IRMA; SALAS, LILIANA

BRAZILIAN JOURNAL OF BIOLOGY

INT INST ECOLOGY

Lugar: SAO CARLOS, SP; Año: 2013 vol. 73 p. 357 - 366

1519-6984

The aim of this work was to determine the structure of the benthic entomofauna and its variation along the El Tala River (Catamarca, Argentina). The following variables were determined in situ: altitude, latitude and longitude, bedstream width, river depth, river-current speed, water and air temperatures. Benthic insects were collected at five sampling stations, with a square parcel sampler of 0.09-m2 area and 300-µm net opening and identified to the family level. Faunal density, richness, and diversity exhibited a longitudinal variation. Sampling Station 5 showed the highest family richness (17), the highest value for the Shannon-Wiener index (2.74), and the lowest value in Simpson?s Dominance index (D = 0.22). The water quality of El Tala River is Class I (very clean and nonimpacted), according to the results obtained from the application of the biotic Biological-Monitoring?Working-Party and Average-Store-per-Taxon indices. Key words: benthonic insects, longitudinal variation, biotic indices, bioindicators, mountain rivers.