Effects of time of year and limb removal on rates of ecdysis of eyed and eyestalkless fiddler crabs, Uca pugilator

Abstract

The incidence of ecdysis among monthly samples of female Uca pugilator, both intact and eyestalkless, was determined from May, 1974 through April, 1975. Among both the intact and eyestalkless crabs the percentages of the crabs that underwent ecdysis varied during the year. During the height of the breeding season in particular, ecdyses were rare among the eyestalkless crabs and absent among the intact ones. The effects of limb removal, either followed by or preceded by eyestalk removal, on the rate of ecdysis were also determined. Eyestalkless crabs from which 4 walking legs were removed either the day before or the day after their eyestalks had been removed underwent ecdysis at a slower rate than crabs lacking only eyestalks, but faster than crabs lacking only 4 walking legs. The high incidence of precocious ecdyses induced by removing large numbers of limbs from eyed crabs appears to be due to the number of limbs removed and not to the weight or volume of limb tissue removed.