PS 21-10: Behavior and chemical cues reduce conspecific predation of newly-hatched crab larvae
Seth H. Miller and Steven G. Morgan. University of California, Davis
Clouds of eggs and larvae of benthic marine organisms are released amid high densities of filter-feeding and predatory adults and are highly subject to being consumed, even by conspecifics or their own parent. Behaviors of adults and larvae, chemical defenses, and chemical recognition of propagules by parents can reduce consumption until these clouds diffuse and disperse into open waters where predation may be reduced. In laboratory feeding trials, female shore crabs (Hemigrapsus oregonensis) that had released their larvae more than 4 wk before the experiment ate significantly more conspecific larvae than females that had recently released their larvae. Additionally, crabs that recently released their larvae consumed fewer of their own offspring than larvae from other females. Thus, suppression of filter-feeding by females that have recently released larvae and chemical recognition of offspring may both reduce conspecific predation of newly-released larvae.