The spawning dynamics of California market squid (Doryteuthis opalescens) as revealed by laboratory observations

Abstract

California market squid (Doryteuthis opalescens) are fast-growing, semelparous and short-lived, making them the archetypal live-fast, die-young species. They form spawning aggregations that are targeted by a wide variety of predators and the largest commercial fishery in California. Despite their ecological and economic importance, relatively little is known about the life history of spawning D. opalescens. To gain insight into this life stage we performed controlled observational experiments on groups of mature D. opalescens collected from the spawning grounds. In all trials we observed extreme synchrony in egg-deposition and subsequent mortality. Importantly, we observed a prespawning period in which mature D. opalescens congregate on the spawning grounds for up to 2 weeks prior to spawning. During this period they are susceptible to predation and harvesting. We also present the first empirical estimates of postspawning mortality and egg-deposition rates. Taken together, our results suggest that the first day of spawning is critical to the viability of this species.