After 5-h desiccation, surviving declawed crabs 

 (Group VI) recovered more slowly than did crabs of 

 Group V. Maternal preening was delayed and egg 

 mortality during prehatch did not peak until 6 

 days after desiccation (Figui'e 3). As noted previ- 

 ously, maximum egg and larval mortality nor- 

 mally occurred at major hatch, but difficulty in 

 maintaining body elevation probably inhibited 

 preening for Group VI during posthatch. Con- 

 sequently, maximum egg and larval mortality oc- 

 curred 3 days after major hatch and time needed to 

 clean pleopods was extended to 9 days. 



Group VI recovery from stress was sufficient to 

 produce prehatch mortality of 9.8%, an increase of 

 2.8'r above control Group IV (Table 1). Extended 

 posthatch yielded 50. 4'^> egg and larval mortality, 

 the highest of any group. Total mortality for sur- 

 viving crabs in Group VI (60. 2'/? i was a marked 

 increase of 46.5'^f above that of control Group IV 

 (Table 1) even excluding lOQ'i mortality values 

 from 18 dead crabs. 



Figure 4. — Hatching success in ovigerous stone crabs as re- 

 lated to desiccation and autospasy Mean (vertical line), range 

 (horizontal line! and 95'7f confidence intervals (bar) about the 

 mean. Set A includes untreated Group I crabs. Group II crabs 

 exposed to 2-h desiccation and Group III crabs exposed to 5-h 

 desiccation; Set B includes untreated Group IV crabs. Group V 

 crabs, both claws removed after 2-h desiccation and Group VI 

 crabs, both claws removed after 5-h desiccation; Set C includes 

 only crabs that survived desiccation and autospasy in Groups V 

 and VI. 



Mean Hatchinj; Success 



Mean hatching success for control crabs in Ex- 

 periment I (Group I) was 91. G*;?. Desiccation from 

 air exposure for 2h (Group II) decreased success to 

 78.6'7f and desiccation from 5-h air exposure 

 (Group III) decreased success to 60.3'?. Mean 

 hatching success for control crabs in Experiment 

 II ( Group IV) was 86.3'r . Stress from 2-h desicca- 

 tion plus autospasy (Group V) decreased success 

 from Group IV to 49. 69^ and stress form 5-h desic- 

 cation plus autospasy (Group VI) decreased suc- 

 cess to 18.8'7f (Figure 4). 



Sunim.iry 



Desiccation of eggs by air exposure of ovigerous 

 females caused reduction in larval hatching suc- 

 cess that was directly related to length of expo- 

 sure. Desiccation weakened normal crab 

 autotomic muscular reflex, and experimental de- 

 clawing resulted in death of 34.4'f of crabs ex- 

 posed 2 h and 52.9% of crabs exposed 5 h. 



Stress from autospasy after 2-h desiccation did 

 not increase mean egg and larval mortality for 

 surviving crabs above that for crabs desiccated 

 only. Related to controls. Group II (2-h desicca- 

 tion) and Group V ( 2-h desiccation'autospasy) had 

 nearly identical total mortalities, 12.9% and 

 13.0%, respectively. Claw loss delayed maternal 

 egg mass preening, and reversed the prehatch 



posthatch egg mortality ratio of crabs desiccated 2 

 h from 12.1:9.3 (Group II) to 8.5:18.1 (Group V). 



Effects of stress after 5-h air exposure were less 

 definitive. Egg and larval mortality for surviving 

 declawed crabs exposed to 5-h desiccation was 

 15.5% higher than was mortality for similarly ex- 

 posed whole crabs when related to controls. Ma- 

 ternal egg preening by declawed crabs was obvi- 

 ously affected by claw loss, but small sample size 

 (16) in surviving declawed crabs and overlap in 

 confidence intervals for the 5-h desiccation groups 

 made differences in mortalities inconclusive. 



The stone crab fishery, unlike the blue crab 

 fishery which allows permanent removal of whole 

 animals, realizes high stability and recruitment 

 by release of reproductively active crabs capable of 

 claw regeneration. Present harvesting techniques 

 adversely affect this stability by subjecting crabs 

 to air exposure and desiccation. When crabs are 

 ovigerous, desiccation causes a definite reduction 

 in larval hatching succe.ss and is related to crab 

 death and reduced overall population recruit- 

 ment. Protection of ovigerous females by im- 

 mediate release or by use of methods to dampen 

 crabs while on deck is therefore warranted. 



.■\tkn<)\\ Icdynicnts 



This study was funded in part by the U.S. De- 

 partment of Commerce, NCAA, National Marine 

 Fisheries Sei-vice under PL 88-309, Project No. 



699 



