MEPS 421:173-182 (2011)  -  DOI: https://doi.org/10.3354/meps08895

ABSTRACT: Munida is the most diverse and cosmopolitan genus of the galatheid squat lobsters. The group has attracted much attention in recent years from both systematic and evolutionary perspectives, yet information on the biology, ecology and evolution of this genus is very limited. We investigated the genetic parentage of 2 North Atlantic species, M. rugosa and M. sarsi, sampled from the Clyde Sea on the west coast of Scotland. Microsatellite markers were used to establish the parental contribution from embryos of berried females (M. rugosa, n = 25 and M. sarsi, n = 5). The frequency of multiple paternity observed in both species (86% for M. rugosa and 100% for M. sarsi) is the highest ever reported for any marine crustaceans. Invariably more than 2 sires were involved in each case (minimum of 2 to 3 for M. rugosa and 4 for M. sarsi). Our findings indicate that multiple paternity is likely to be the norm in both species. Within most multiply sired broods, sire contribution was highly skewed towards a single male (66% of broods for M. rugosa and 100% for M. sarsi). Furthermore, embryos from different sires were randomly distributed across the female’s brood patch. This is the first report of multiple paternity in galatheids. While a number of theories can account for the high incidence of multiple paternity in these species (e.g. convenience polyandry as a result of cryptic female choice, forced copulations, the influence of fishing pressures), at present it is not possible to disentangle their individual and/or combined effects.

KEY WORDS: Galatheids · Crustacean mating system · Polyandry · Munida spp.