Social and Behavioral Sciences Commons^™

Female terrestrial isopods carry eggs and young throughout early development, a habit that places constraints on reproductive success. One such constraint is impaired locomotion during the brooding period. Brooding and non-brooding females were subjected to a negative-phototaxis experiment in which females moved away from a light source along a graduated surface. In both groups, velocity was positively and significantly correlated with distance traveled. Velocity and distance were also significantly associated with the physical dimensions of the exoskelton: larger females moved greater distances at faster speeds. Non-brooding females, however, moved significantly farther at significantly greater velocities than brooding females, suggesting that …