The effect of limb loss and regeneration on the growth of the edible crab, Cancer pagurus, L

Abstract

Male and female crabs ( Cancer pagurus L.) were subjected to various limb loss treatments to determine the effects of limb loss and regeneration on body growth and timing of moulting. Compared with no limb loss, severe limb loss (2 chelae or 6 legs removed) caused a reduction of the increment in carapace width at moulting by up to 25%. Less severe limb loss marginally reduced body growth. Depending upon the time in the moult cycle of autotomy, limb loss, particularly when severe, appeared initially to inhibit moulting, or to stimulate ecdysis so that the treatment replicates all moulted within a short period. The incidence of chelae loss in the crab stocks in Norfolk, Yorkshire and Devon was ≈ 10%. It would appear that within a population the reduction in body growth and any initial inhibition of moulting is counteracted to some extent by stimulation of moulting. Although the effect of limb loss and regeneration on the growth rate of C. pagurus has not been quantitatively determined, it is unlikely to be a factor greatly affecting the determination of growth for a yield assessment. The process of commercially removing claws or legs and returning the crab to the sea to regenerate new limbs is not recommended.