FILINIA (ROTIFERA, MONOGONONTA) POPULATIONS IN FRENCH-GUYANA - F-NOVAEZEALANDIAE, F-SALTATOR, WITH REMARKS ON THE VARIABILITY OF SOME CHARACTERS

Two species of Filinia, F. novaezealandiae and F. saltator, were colle cted in April and September 1991 in Petit Saut reservoir on the Sinnam ary River (French Guayana). Their main characters (length of the later al and caudal bristles, body length, numbers of unci teeth) are studie d. Compared to the homogeneous September population (F. novaezealandia e alone), the coexisting April populations had shorter bristles and a lower number of teeth in the unci. Several converging observations (pr evious and present) suggest that the length of bristles depends probab ly on predator abundance. The variability of the number of teeth on th e unci observed in many species of this genus is discussed.