Nursery habitats and life history traits of the green tiger shrimp Penaeus semisulcatus (De Haan, 1844) in the Saudi waters of the Arabian Gulf

Abstract

The green tiger shrimp Penaeus semisulcatus is one of most productive fisheries in the Saudi waters of the Arabian Gulf. Currently, two artisanal fleets harvest the stock and management is limited to input control measures. Progress to quantitatively-based, sustainability-oriented management is precluded by the lack of basic ecological and biological knowledge. In this study we identify nursery and juvenile habitats, spawning seasons, estimate maturity of females, cohort composition, individual growth, natural mortality, and derive biological reference points. Beach seining and trawl surveys show that coastal embayment systems are important nursery grounds. The population is composed of a maximum of three cohorts born at 6 months intervals. Among three growth models, a 2-parameters version of the Gompertz model was the most supported by the data with individual growth parameters of 57mm carapace length (CL) asymptotic length and 1.9yr−1 growth rate coefficient. Spawning is continuous along the year with two main peaks in early summer and in December. At 23mm of CL 50% of females are mature, and at 29mm CL 95% have reached maturity. Natural mortality was estimated at 2.391yr−1. Fishing mortality corresponding to a target of 40% of virgin spawning biomass per recruit is 1.3yr−1. All parameters are estimated with good precision. These life history traits correspond to a short-lived stock whose abundance is driven by recent recruitment pulses.