Claws, Legs, and Eggs: Linking Injuries to Reproductive Function in Crayfish

Appendage loss in crayfish can induce physiological stress, fitness consequences, or be fatal. While the ecological importance of chelipeds (claws) is well documented, the impact of losing other appendages remains understudied. Furthermore, there are almost no records of injury rates for other appendages in stocking conditions. This study evaluated the frequency of appendage injuries in a laboratory stock of marbled crayfish (Procambarus virginalis) and experimentally tested their importance for oviposition performance. First, we assessed stock individuals for appendage injuries, body size, and reproductive stage. Second, we conducted a controlled experiment in which we removed one or both fifth pereiopods to analyze the impacts on ovulation timing, fecundity, and spatial egg distribution along the pleon. In stock analysis, claw status, rather than body size, was significantly associated with appendage status. The loss of one or both claws initiated a vulnerability cycle, increasing injury rates, especially in the antennae and the 4th and 5th walking leg pairs. Injury rates also fluctuated within reproductive stages. In the experimental manipulation, the loss of the fifth pereiopod did not significantly impair fecundity, delay ovulation,while effects on egg distribution were minor and inconsistent. Compensatory behaviors likely maintain successful egg attachment and distribution despite fifth-pereiopod loss.