Multiple paternity and complex fertilisation dynamics in the squid Loligo vulgaris reynaudii

Abstract

Predictions regarding multiple paternity and male mating competition in the squid Loligo vulgaris reynaudii D'Orbigny, based upon behavioural observations, were tested by DNA fingerprinting of offspring within wild caught egg strings along with putative female and male parents. Results confirm that the potential for multiple mating by females does translate into multiple paternity within broods, at least in some instances, with up to 4 or 5 males gaining fertilisations. Patterns of fertilisation success within egg strings demonstrated distinctly different levels of success by males, both within the brood as a whole but also along the length of a string. These preliminary results confirm an emerging picture of complex genetic mating systems in squid, and suggest the action of intricate patterns of sperm competition and the possibility of cryptic female choice in this species.