Abstract

Studies of mating systems are fundamental to understand the evolutionary forces that shape reproductive behaviors. Polygamy, where individuals mate with multiple partners within a single reproductive period, is one of the most widespread mating strategies in nature. In females, this behavior, referred to as polyandry, can result in increased intrasexual competition and multiple paternity. We investigated the paternity pattern in Allopetrolisthes punctatus (Gu & eacute;rin, 1835), a porcellanid, or porcelain, crab of the rocky-shore infralittoral coast of Chile. To establish its paternity pattern, eight novel microsatellite loci were developed and genetic analyses of 16 females and their offspring were performed. The analysis revealed evidence of multiple paternity in two broods (12.5%), with at least three males contributing to each brood. Paternity was skewed in both cases, with a single male siring most of the offspring (70%). Due to the lack of behavioral data on the mating system of A. punctatus, the mechanisms underlying the relatively low incidence of multiple paternity in this species compared to other anomuran crabs remain unclear; nevertheless, sperm competition and cryptic female choice are plausible contributing factors. Further research is necessary to clarify the adaptive significance of multiple paternity in this species, and its implications for the evolution of mating systems.