THE OCCURRENCE OF THE GENUS-BRACHIONUS DALLAS, 1766 (ROTATORIA), IN NORTHEASTERN TEXAS RESERVOIRS

An extensive study of the occurrence of rotifers of the genus Brachion us, Family Brachionidae, Order Ploima, Class Monogonota was conducted from 1982 to 1987 in seven northeastern Texas reservoirs. Eleven speci es of Brachionus were identified. Brachionus angularis, B. bidentata, B. havanaensis, B. rubens, B. quadridentatus, and B. caudatus were pre sent during all seasons. Brachionus calyciflorus occurred in the sprin g and autumn. Brachionus budapestensis was identified in March and Jun e and from September to November. No patterns could be discerned for B . urceolaris, B. rubens, B. variabilis, and B. zahnisera. The smallest number of species occurred during the winter in all reservoirs. All r eservoirs had nine species of Brachionus except Cypress Springs which only had four species.