Diversity in growth and longevity in short-lived animals: squid of the suborder Oegopsina

This article is an overview of age and growth studies of squid belonging to the suborder Oegopsina, which includes the majority (similar to215) of squid species inhabiting offshore waters of the continental shelves and pelagic waters of the world ocean. Three main periods in the history of age and growth studies of oegopsin squid are identified. A brief history of the different methods applied to study oegopsin age and growth is presented. The lifespan of oegopsin squid varies from almost 3 months in small pelagic tropical species to 2 years in polar and deepwater species. Generally, the lifespan of similar-sized oegopsin squid increases with latitude. Growth of the majority of oegopsin squid is best described by one of the asymptotic growth functions, but some tropical squid are characterised by non-asymptotic growth. Many aspects of growth variability are discussed, such as ontogenetic, sexual, intra-specific, geographical, inter-annual and inter-specific variations. The fast growth rates of oegopsin squid give them the advantage of passing quickly through the most vulnerable first trophic levels of the oceanic food web, enabling them to compete successfully with nektonic fishes.