Meeting Abstract

22.4  Friday, Jan. 4  Are two parents better than one? Examining the effects of biparental care in a stomatopod crustacean WRIGHT, ML*; CALDWELL, RL; UC Berkeley; UC Berkeley wrightml@berkeley.edu

Although social monogamy and biparental care have been extensively studied in birds, mammals, and fish, few studies have been conducted on invertebrate species. Social monogamy is characteristic of several marine crustaceans, while biparental care is only known in a single genus of monogamous stomatopod crustaceans, Pullosquilla. In Pullosquilla litoralis, males and females spend statistically equal amounts of time aerating eggs with their pleopods and removing fouled eggs from clutches. Under certain conditions, P. litoralis is also capable of double-clutching. Based on laboratory observations, we suspected that biparental care also occurs in Pullosquilla thomassini, a congener with very similar ecology and behaviors. Through observational studies and experiments conducted at Lizard Island Research Station, Queensland, Australia, we characterized parental care in P.thomassini and examined the effects of uni- and biparental care on the survival and development of egg clutches and weight gain in parents. We found that parental care behaviors in P. thomassini are similar to those of P. litoralis and that males and females provide similar amounts and types of care. We observed two double-clutches in the field. We found that there were no clear benefits of biparental care over uniparental care, but that any form of parental care decreases the amount of weight lost by developing egg clutches. There were also no significant differences in the survival of egg clutches between care provided by males or females. These results suggest that biparental care is not evolutionarily maintained simply by short-term fitness gains in egg development and survival in P. thomassini. Instead, it may be selected for with other life history traits, such as double-clutching, that increase lifetime reproductive success, but do not affect the size or developmental outcome of individual clutches.