The Biological bulletin (20368204962)

Title: The Biological bulletin
Identifier: biologicalbullet143mari (find matches)
Year: [1] (s)
Authors: Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annual report 1907/08-1952; Lillie, Frank Rattray, 1870-1947; Moore, Carl Richard, 1892-; Redfield, Alfred Clarence, 1890-1983
Subjects: Biology; Zoology; Biology; Marine Biology
Publisher: Woods Hole, Mass. : Marine Biological Laboratory
Contributing Library: MBLWHOI Library
Digitizing Sponsor: MBLWHOI Library



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ECDYSES STIMULATED BY LIMB LOSS 225
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FIGURE 1. Specimens of crabs with regenerating limb buds, (a, b) Gecarcinus latcralis. (c) Callinectes sapidits and (d) L'cu piti/iut.r. Eiglit, 4, 6, and 6 walking legs were removed from animals (a, b) 45, (c) 3o, and (d) 20 days previous to the time of photography. normal. We have performed a series of experiments on (.iecarcnnis to compare the relative effectiveness of eyestalk extirpation and limh loss in inducing pre- cocious molts. We find that eyestalk removal leads to the most rapid molting preparations (Table I) but is accompanied with 100^ mortality at the time of ecdyses (Fig. 2). Molts induced by limb loss, though somewhat delayed in time, almost always lead to healthy, normal animals ( Fig. 2). Even those specimens deprived of 8 walk- ing legs, though clumsy in their movements, molt successfully almost 100^ of the time. Indeed, in most experiments, we observe no deaths following such treatment. Minimum number oj limb autotomies required to stimulate precocious moltiruj preparations These and the remaining experiments in this paper were performed with Gecarcinus. Loss of from 1 to 4 limbs had no effect on the duration of the molt cycle (Table II). Animals which have lost 5 limbs, on the other hand, respond except when kept in community tanks. Loss of from 6 to 8 limbs, including various com- binations of chelipeds and pereiopods, is almost lOO^r effective. Since in Gecarcinus the chelipeds comprise as much as 35c/c (21 to 35r/r ; Table III) of the total body weight, whereas the walking legs contribute 11 to \7c/c (Table III),