Abnormalities in two Bosmina longirostris s.l. (OF Müller, 1785) populations (Crustacea: Branchiopoda: Bosminidae)

Abstract

Abnormal trunk morphology is observed in two populations of Bosmina longirostris. One population is from a trout cultivation pond, the other from a pond with a very high angling pressure. The length and shape of the first antenna (trunk) of part of the population are abnormal. No abnormalities were observed at three locations, with low or no angling pressure. The observations are considered in the context of the described variation in the first antenna of this species. Possible causes of the abnormalities are discussed.