Biodiversity, spatial, and seasonal distribution of the zooplankton community in semi-intensive fish farms in Rondônia state, Brazil

In this study we determined the spatial and seasonal distribution (rainfall and drought) of the zooplankton community in 30 fish farms in the microregions of Vale do Jamari and Central-East of Rondônia. The experiment was organized in a completely randomized factorial scheme. The species were considered in composition, richness, frequency of occurrence, relative abundance and diversity indices (H’, J and S). There were records of greater richness of Copepoda (550 to 1214), Ostracoda (360 to 989.6), Rotifera (71 to 431) and Cladocera (344 to 990). In the Jamari Valley, the most abundant species (Individuals per 100 mL) were Ostracoda (323), Copepoda (160) and Rotifera (111). In the Center- East, they were Copepoda (287), Rotifera (108) and Ostracoda (106). In the two microregions there were variations in the seasonal distribution, except for the populations of the phylum Cloadocera. The diversity indices differed, registering a greater diversity of populations of Ostracoda in the Jamari Valley and Copepoda in the Center-East and in the rainy season.