Meeting Abstract
Although social monogamy, when a male and female live together for at least one breeding episode, is characteristic of several crustaceans, the evolutionary origins of this mating system are not well understood. I assessed two alternative hypotheses for the origin of social monogamy in Lysiosquilloid stomatopod crustaceans using comparative phylogenetic methods. Most stomatopod species are promiscuous or serially monogamous animals that leave burrows and cavities to actively hunt prey. In contrast, Lysiosquilloid stomatopods include eight genera that form socially monogamous pairs. Many Lysiosquilloid stomatopods are sit-and-wait predators that seldom leave their burrows. I examined the novel hypothesis that the Lysiosquilloidea may have evolved long-term social monogamy in association with other behavioral traits that facilitated a sedentary lifestyle, allowing stomatopods to escape high levels of predation. I also examined the hypothesis that fitness benefits conferred by biparental care selected for the origin of social monogamy in Lysiosquilloids. The associations between social monogamy, predation strategy, burrowing behavior, parental care, and habitat preference were examined on a ML tree of 66 stomatopod species. Burrowing, sit-and-wait predation, and social monogamy evolved sequentially in the Stomatopoda, supporting the predictions of the sedentary lifestyle hypothesis. This novel evolutionary route to social monogamy through sit-and-wait predation may be associated with the marine lagoons that many Lysiosquilloids inhabit. I also found evidence that biparental care evolved after long-term social monogamy. These findings emphasize the importance of considering a diversity of taxa and environments when studying the evolution of behavioral traits.
