Effects chelipeds regeneration in molting and growth of male Cryphiops caementarius Molina 1782 (Decapod, Palaemonidae)

Abstract

The aim was to evaluate the effects of regeneration of chelipeds in molting and growth of male shrimp Cryphiops caementarius and to characterize the stages of regeneration of these appendices. Adult male shrimp captured in the Pativilca River (Lima, Perú) were used and selected in molt stage C, with complete cephalothoracic appendages, and no signs of lacerations on the body. The treatments were: autotomy of the major cheliped, autotomy of the minor cheliped, autotomy of both chelipeds and shrimp with intact chelipeds (control). Autotomy of chelipeds was induced by pressing with clamp the palm of the propodus to produce rupture. Eight stages of chelipeds regeneration before ecdysis were described for the first time. The major autotomized cheliped regenerated 58 % of its initial length and the minor cheliped regenerated 75.2 %. When both chelipeds were autotomized, the major chelipeds 41.3 % regenerated and minor cheliped 67.6 % regenerated. In all cases, regeneration occurred in the first post-autotomy molt. Autotomy of chelipeds significantly reduced (p<0.05) the period to 18 days in those with autotomy of both chelipeds, 26 and 28 days with a single cheliped autotomy, and control was 33 days. Autotomy of both chelipeds significantly reduced (p<0.05) weight gain (-21.67 %), followed by those who had the major autotomy cheliped (-11.12 %) and minor cheliped (-2.29 %); control growth was normal growing in 7.96 % by weight. According to the results, it is possible to infer the negative effect that autotomy of chelipeds would have in commercial culture of the species.