Body and Claw Size At Autotomy Affect the Morphology of Regenerated Claws of the Sand Fiddler Crab, Uca pugilator

TLDR: The relative size of regenerated claws was greater among males that had relatively large original claws prior to autotomy, suggesting that males may continue to signal their quality by regenerating a new claw that is relatively long.

Abstract: Sand fiddler crab males, Uca pugilator (Brachyura: Ocypodidae), use their single enlarged claw as a weapon in fights for burrows and as a signal to attract females to burrows. Seventy-three males from a South Carolina marsh were in reared in the laboratory to determine if body size at the time of claw loss affects the morphology of the claw that subsequently regenerates. Thirty-six males were induced to autotomize claws and regenerated new ones. Thirty-seven males retained original claws. Across four molts, males regenerating claws gained more in claw length but less in body width and overall mass than males retaining original claws. The first molt accounted for these differences as males regenerating claws gained relatively little in body size but added much in claw length. Regenerated claws were more slender, having smaller dimensions of the manus relative to claw length. As the manus houses the claw closer muscle, regenerated claws are expected to be less powerful and appear more designed for ...