Population ecology of the intertidal xanthid crab Leptodius exaratus (H. Milne Edwards, 1834) (Decapoda: Brachyura: Xanthidae) on rocky shores in Kuwait, Arabian (Persian) Gulf

Abstract

Leptodius exaratus (H. Milne Edwards, 1834) is an exploited species that has been used as bait for recreational fishing in Kuwait. The biological and ecological aspects of the species required to manage this practice are limited. We investigated the life history and population ecology of L. exaratus in the northwestern Arabian (Persian) Gulf. The spawning season of the crab in Kuwait starts in the late spring and continues through the summer and ends in September. Fecundity is highly correlated to female body size and ranges 2,533–11,991 eggs clutch–1, with a mean number of 7,055 eggs clutch–1. Juveniles are generally recruited between July and September, with lower minor recruitment levels occurring in October and November. Growth is highly seasonal, being slow during the cold season (October-February) and high during the warmer season (March and September), with a higher growth rate in males than in females. The seasonality of growth and reproduction of L. exaratus in the region is strongly related to ambient air and water temperatures. Sexual dimorphism is highly significant between males and females with males, reaching reproductive maturity at 17.43 ± 0.53 mm carapace width (CW) and females at 9.58 ± 1.21 mm CW. The overall sex ratio for the species is 0.8:1 (males:females). Furthermore, the life span of 3–4 yr and an overall mortality slightly higher in males than in females. The results of our study could be used to determine fishery management strategies such as minimum catch sizes and closures periods. The results on life history and dynamics of the complex life cycle of L. exaratus contribute to conservation and sustainable exploitation of the species in Kuwait.