|Reproduction Preferences Additional Information||
- Reproduction, and therefore production of gametes, occurs throughout the year although some seasonal peaks of reproduction have been observed. In Helgoland waters, for example, two peaks were observed, the main one in summer and another smaller peak in winter (Nair & Anger, 1980).
- The mating system is polygynous. Several broods of offspring are produced, each potentially fertilised by a different male. Males are believed to seek out mature females attracted by female pheromones.
- There is no sperm storage, and fertilisation is external.
- There is no larval stage. Embryos are brooded in a marsupium, beneath the thorax, formed by the oostegites (a series of flattened plates projecting from basal segments). Embryos are released as subjuveniles with incompletely developed eighth thoracopods and certain differences in body proportions and pigmentation.
- In laboratory investigations, life span, time to maturity and fecundity were strongly influenced by temperature (Nair & Anger, 1979). At 20 °C the time to reach maturity is 2 months, about half the value observed at 10 °C. Field investigations in Helgoland observed age at maturity to be 6 months for new generations produced in low winter temperatures of 7-8 °C (Nair & Anger, 1980).
- Growth rate also increases with increasing temperature but life span is shorter and individuals are smaller at higher temperatures (Nair & Anger, 1979).