The Zooplanktonic Communities of Cârja And Mălina Farms (Romania)

Zooplankton communities represent an important link in the aquatic food web with an important role in the transmission of matter and energy from producers to consumers. Also, they are excellent indicators of water quality and their functioning through their central position in the food web. This study presents the taxonomic composition, abundance, and spatio-temporal distribution of zooplankton communities in two pond ecosystems with different water supply sources, in two seasons (spring and autumn). Diversity and similarity for the three zooplankton groups between the two fish farms were also calculated. The study was conducted in 2020. The zooplankton taxonomic groups identified in the samples taken were: Rotifers, Cladocera and Copepods. In the Mălina aquatic ecosystem, species from the Cladocera taxonomic group dominate, with the species Daphnia cristata, Daphnia longispina and Daphnia cuculata, while in the Cârja aquatic ecosystem, species from the Rotifera taxonomic group dominate, namely Brachionus angularis, Brachionus rubens, Brachionus urceolaris and Trichocerca tigris. Comparing the diversity of the two aquatic ecosystems (which are water supplied by distinct rivers), we conclude that the Mălina farm has the greater diversity for all three groups of zooplankton. Using the Sorenson Diversity Index (IS) to see the degree of similarity of the taxonomic composition between the two aquatic ecosystems studied, it was observed that for the Rotifera group, the similarity is 56%, for the Cladocera group 50% and for the Copepoda group 80%.