Differences in prevalence of multiple paternity in the spiny spider crabMaja brachydactylain two localities that differ in female fecundity, fishing intensity, and management measures

Abstract

Many marine species are under high fishing pressure, which can cause alterations in their mating systems and the structure of their populations. The spiny spider crab Maja brachydactyla is a commercial decapod on the east Atlantic coast. In Galicia, the most exploited region in Spain, the landing of ovigerous females is prohibited, favouring exploitation focused on males. The removal of males, especially the largest ones, may lead to sperm limitation and a reduction in the average size over generations. In these cases, polyandry can work as a mechanism to protect females against sperm limitation and to increase genetic diversity and effective population size. This study analyses the multiple paternity in M. brachydactyla in two localities that differ in female fecundity, fishing intensity, and management measures. Our results showed multiple paternity in this species for the first time, with a moderate bias between sires. However, the frequency of multiple paternity was almost seven times higher in the intensely exploited Golfo Ártabro (NW Spain; 69%) than in Carna (W Ireland; 10%), where exploitation levels and female fecundity are lower.

Influence of Storage Time on the DNA Integrity and Viability of Spermatozoa of the Spider Crab Maja brachydactyla

“…It could be interpreted as this species having the ability of mating throughout the whole year, and these migrations for mating in autumn are only used to facilitate the exchange of gametes. These mating congregations also favour the multiple paternity (polyandry), a reproductive mechanism described for this species [104]. We verified, in some dissections of seminal receptacles, the existence of separated ejaculates.…”