Table l— Percent egg mortality in ovigerous stone crabs as 

 related til desiccation and autospasv. Experiment I comparesegg 

 mortality after effects of desiccation and experiment 11 compares 

 egg mortality after desiccation followed by removal of both claws 

 (autospasy). 



deficiency within the egg mass and lack of abdom- 

 inal movement may have hindered successful lar- 

 val hatching. Davis (19651 separated eggs from 

 female blue crab, Callincctcs sapiclus. and noted a 

 decrease in hatching success if eggs remained in 

 small clusters, presumably due to insufficient 

 oxygen. Rice and Williamson (1970) found that 

 decapod larvae hatched from ovigerous females 

 were weakened if oxygenated water could not be 

 replenished. 



Prehatch mortality for Group III (5.9^r ) was less 

 than that of Group II, but was still greater than 

 that of Group I (Table 1), Posthatch mortality 

 (33.8%) was considerably higher than Group I or 

 Group II. Total mortality for Group III 139,7%) 

 represented a mean increase of 18.3% mortality 

 above that of Group II and a mean increase of 

 31,3% above that of Group I (Table 1). 



Expcrinicnl II 



Autotomizer muscle reflexes were adversely af- 

 fected in crabs subjected to air exposure, and de- 

 clawing often resulted in jagged wounds and 

 severance of the artery proximal to the hypoder- 

 mal diaphragm. Unrestricted hemorrhaging 

 caused death in 8 crabs in Group V and 14 crabs in 

 Group VI. Death in seven additional crabs (three 

 in Group V, four in Group VI) could not be 

 explained as above, but also occurred after deelaw- 

 ing. Resulting 100% egg mass mortality for 34,4% 

 of Group V and 52,9% of Group VI notably reduced 

 group mean hatching success related to control 

 Group IV (Table D, 



Wood and Wood (1932) found any treatment 

 which weakened brachyurans affected muscular 

 responses, preventing normal autotomic reflex; 

 they further stated that American crayfish (As- 

 tacidae) held captive for any length of time were 



vitiated and lacked normal reflex. Davis^ related 

 wound size and body fluid loss in reporting 53.79; 

 death in M. mercenaria held for 10 days in labora- 

 tory tanks and then declawed using commercial 

 methods. 



Loss of both claws after desiccation reduced 

 preening of eggs by surviving crabs, resulting in 

 an apparent initial egg mass mortality below that 

 of Group IV (Figure 3i, 



Group V crabs (2-h desiccation) recovered 

 quickly and compensated for claw loss by propping 

 themselves against sides of compartments; rocks 

 and shells common where stone crabs occur may 

 be used similarly in nature. Prehatch mortality 

 peaked 3 days after desiccation, Posthatch mortal- 

 ity was higher and more erratic than that of con- 

 trol Group IV. Prehatch mortality (8,5%) was 

 slightly higher than that of Group IV (7,0%), but 

 posthatch mortality (18,1%) was almost three 

 times higher than that of control group (Table II, 

 Total mortality for Group V (26,6%) was 12,9% 

 above control (Group IV I, 



^Davis, G. E, Interim report June, 1977. National Park 

 Service Stone Crab Studv. Everglades National Park, Box 279, 

 Homestead, FL;«030. 



S 120 



E 



! too-- 

 80 



60 



4 



20 



GROUP H 

 GROUP I 

 GROUP Vl 



-H — I — I — I — I — I — I — I — ^ 



2 3 4 5 6 



Prehatch 

 Doys after DA 



H — I — I 1— I — I 1 — I — I t—l 



MH I 



2 S 4 5 6 

 Posthatch 

 Days after MH 



Fli.lKK :i,— Average daily percent egg iniirtality in ovigerous 

 stone crabs as related to desiccation and autospasy. Group IV 

 crabs were untreated (control). Group V crabs had both claws 

 removed lautospasyi after 2-h desiccation, and Group VI crabs 

 had both claws removed after .>h desiccation n.-\ - day of desic- 

 cation and autospasy; MH - day when major hatching occurred; 

 Prehatch - days following DA; Po.sthatch  days following MH. 



698 



