Diversity and distribution of Brachionus community (Rotifera: Brachionidae) at lake Maryout, Alexandria, Egypt

Brachionus diversity was studied seasonally at lake Maryout during the period from September 2014 to August 2015 at the surface water samples of nine selected sampling locations to examine its spatial and temporal variability in relation to some physicochemical parameters. A total of ten Brachionus species were recorded during this study period viz, Brachionus plicatilis, B. angularis, B. calyciflorus, B. urceolaris, B. caudatus, B. quadridentatus, B. budapestinensis, B. dimidiatus, B. falcatus and B. rubens. The highest abundance (1376000 ind./m3) of Brachionus community was recorded at site 2 during winter while the lowest one (300 ind./m3) was recorded at sites 4, 8, 9 during autumn and site 4 during summer. B. plicatilis, B. angularis and B. calyciflorus formed collectively (91.1% of the total Brachionus community). The presence of these species of Brachionus in high composition indicates eutrophication of the Lake. The highest diversity (9 species) was recorded at sampling locations 4 and 7 but the lowest one (4 species) occurred at site 9.