The Effect of Eyestalk Removal, Wounding and Limb Loss Upon Moulting and Proecdysis in the Prawn Palaemon Elegans (Rathke)

Most current literature concerning moult control in crustaceans concludes that initiation of premoult is controlled by changes in the level of moult-inhibiting hormone (MIH) produced by the eyestalk neurosecretory organs. MIH is thought to act by repressing the secretory activity of the Y-organs, preventing increases in circulating ecdysteriod levels, necessary for moulting (see Kleinholz & Keller, 1979). This hypothesis is based upon the observation that eyestalk removal, by removing the source of MIH, leads to accelerated moulting (see Passano, 1960; Vernet-Cornubert, 1961; Sochasky, 1973, for reviews), and it survives despite many contrary reports indicating that moulting is unaffected by eyestalk removal (Sochasky, 1973). Perhaps the best known of the most contradictory data of this nature have been reported for Palaemon serratus for which Drach (1944, 1947), Panouse (1946, 1947) have shown that eyestalk removal generally accelerates moulting in this species. In contrast, Scheer & Scheer (1954) and Carlisle (1953) demonstrated no moult inhibition in this species following eyestalk removal.