Copepods (Crustacea, Maxillopoda) from shallow reservoirs Copépodes (Crustacea, Maxillopoda) em reservatórios rasos

AIM: Among the planktonic microcrustaceans, copepods Cyclopoida and Calanoida are the most representative groups, being the largest biomass of the plankton community. The aim of this work is to catalogue and analyze the distribution of copepod species (Crustacea, Maxillopoda) in pelagic and littoral zones from small reservoirs in the northwest of the S o Paulo State, in dry and rainy seasons (2007 and 2009). METHODS: Zooplankton samplings were carried out in littoral and pelagic zones of 13 small shallow reservoirs (mean depth: 2.6 m) using vertical hauls and plankton net (45 μm). Water physical and chemical parameters were also monitored with a multiparameter Horiba U10. RESULTS: Eighteen species of copepods were identified, 13 Cyclopoida and 5 Calanoida. There was no statistical difference between the distributions of species from the littoral and pelagic zones and neither between dry and rainy seasons. Three species occurred exclusively in the littoral zone - Eucyclops elegans, Paracyclops chiltoni and Mesocyclops ogunnus. Tropocyclops prasinus and Thermocyclops decipiens were the most frequent species in the studied environments. CONCLUSION: Our data suggest that in shallow reservoirs copepods present a homogeneous distribution between the littoral and pelagic zones and Cyclopoida are more diverse than Calanoida. Shallow depths and eutrophic state may be regarded as limiting conditions for the development of Calanoida in these reservoirs. OBJETIVO: Dentre os microcrustáceos planct nicos, os copépodes Cyclopoida e Calanoida s o um dos grupos mais representativos, contribuindo com a maior biomassa para a comunidade planct nica. O presente trabalho tem o objetivo de caracterizar as comunidades de copépodes (Crustacea, Maxillopoda) pelágicos e litoraneos presentes em pequenos reservatórios na regi o noroeste do Estado de S o Paulo, nas esta es seca e chuvosa de 2007 a 2009. MATERIAL E MéTODOS: As amostragens foram realizadas tanto na zona litoranea quanto pelágica de 13 pequenos reservatórios rasos (média de 2,6 m), através de arrastos verticais com rede de plancton (45 μm). Parametros físicos e químicos da água também foram avaliados utilizando-se o aparelho Horiba U10. RESULTADOS: Foram identificadas 18 espécies de copépodes, sendo 13 Cyclopoida e 5 Calanoida. N o houve diferen a estatística entre as distribui es das espécies nas zonas litoraneas e pelágicas bem como entre as esta es. Três espécies ocorreram exclusivamente na zona litoranea - Eucyclops elegans, Paracyclops chiltoni e Mesocyclops ogunnus. As espécies Tropocyclops prasinus e Thermo