Macroinvertebrados bentônicos dos sistemas aquáticos da estação de piscicultura do CEPTA/IBAMA, Pirassununga, SP
Abstract
With the objective to verify the distribution and the taxonomic structure of the
benthic macroinvertebrates fauna of water systems (reservoir, fisheries and channels) of
the CEPTA/IBAMA (Pirassununga, SP), a study with two types of methodologies was
carried out. The samples of the sediment in the reservoir had been carried out with the
Ekman-Birge grab, and in the fisheries and the channels with artificial substrate. The
assemblages of benthic macroinvertebrates had been analyzed taxonomic and structurally.
The larvae of Chironomidae (Diptera) were the main organisms in all the environments.
The predominance of Procladius sp. and Djalmabatista pulcher was observed in the two
reservoirs. The spatial analysis of the taxa distribution in the depths, pointed out with to
major variety of taxa in the less depth regions (< 2m) in the Represa Velha, in contrast of
the Represa Nova. At the same time, the average densities of the organisms had been
opposing in the two reservoirs, presenting respectively major and lesser values in the
intermediate depths (>2<3m). Temporaly, major abundance of macroinvertebrates at the
dry season was observed, where major number of individuals occurred, represented mainly
for the Procladius sp. and D. pulcher. In the faunistic analysis with artificial substrate,
Goeldichironomus maculatus was dominant. There was taxonomic similarity between the
assemblages in the artificial substrates in the reservoirs, fisheries and channels. The cluster
analysis between the sampling methods, clustering the fauna of the baskets with the
artificial substrate in the two reservoirs, and the fauna collected with the Ekman-Birge
grab. This result points out with respect to the problematic use of artificial substrate use as
a tool to characterize the fauna of a system.