Reproduction, seasonality, and copper toxicity in the coastal mysid Praunus flexuosus

The reproductive biology, in response to temperature, season and copper, of it coastal population of opossum shrimps (Crustacea: Mysidacea) was measur ed. The reproductive pattern for Praunus flexuosus at Keyhaven (west Solent , southern England) has maximum activity in April and maximum reproductive effort in May/June. Increasing temperature decreases incubation time and th e reproductive pattern is adapted to compensate for temperature effects. Re production was inhibited with copper exposure. Fertilization of the eggs di d not occur in any copper treatment (5, 25, 75, 200 mug l(-1) copper added) . Brooding females exposed to copper suffered a high abortion rate. The ina bility to produce broods, appears to be a long-term effect, as specimens pr eviously exposed to copper did not produce any broods after two weeks in se awater controls.