The aim of the project is to investigate the impact of endocrine disruptors (EDs) on the reproductive physiology of exposed fish by measuring induced damage to the spermatozoa motility, fertili- sation capacity and morphology as well as their sex steroid and some neurohypophyseal hormone levels. Some enzymes and adenylates directly involved in the bioenergetics of spermatozoa movement are also studied and their activity related to the sperm motility to explain the fast exhaustion of endogenous energy in the pre- sence of xenobiotics. Our approach implicates biological studies firstly at the individual organism level and secondly at the cellular level. Potential endocrine disruptors will be assayed in concentrations which are found in aquatic ecosystems, using the common carp, as a fish model. Although both types of gametes are affected by oestrogens, egg quality assessment requires laborious measurements, while sperm quality is amenable to easy measurem...