ARNOLD, Emily; SHUSTER, Stephen; Northern Arizona University, University of California Berkeley; Northern Arizona University: Use of chemical cues by marines isopods (Paracerceis sculpta) in the location and selection of mates

Chemical cues are used by many animals to locate breeding habitats and mates. Semelparous species face time and energy constraints that require rapid location of suitable breeding habitats, and in aquatic habitats, individuals in such species may use chemical cues to locate their breeding habitat from a distance. We used 3 Y-maze experiments to test for sensitivity to chemical cues in a population of the marine isopod Paracerceis sculpta. This population contains three distinct male morphs, the dominant of which forms breeding aggregations in an intertidal sponge. Females in this population are semelparous and face extremely short receptivity times. In choice tests, females showed no sensitivity to chemical cues from breeding aggregations and no preference between cues from two different male morphs. However, males were attracted to chemical cues from sponges (F=14.81, P<0.0001). Our results indicate that males locate breeding sites using chemical cues from sponges, and that chemical cues from males and from breeding aggregations may be unimportant in female mate choice.