FISHERY BULLETIN; VOL. 83, NO. 4 



NUMBER OF MISSING APPENDAGES 



Figure 2.— Two Rocks, November-December 1978. The relationship between the mean size increment and number of appendages 

 missing for recaptures from February to June 1979, with the sample size and standard error from the mean shown at each point. 



Table 1.— The results of the analysis of variance on size increment 

 for the three tagging trials at Two Rocks with the level of significance 

 denoted by: NS, *, **, *** meaning not significant, P < 0.05, P < 

 0.01, and P < 0.001 respectively, and NA means not applicable. 



the growth rate of injured animals was significant- 

 ly lower than that of uninjured animals, due to reduc- 

 tions in molt increment and an increase in intermolt 

 period. Their research did not demonstrate any pro- 

 portional relationship between the degree of injury 

 and the degree of molt increment depression as had 

 been shown for H. oregonensis and P. crassipes 

 (Kuris and Mager 1975) and also in this study on P. 

 cygnus. Davis (1981) stated that growth rate of P. 

 argus with minor injuries, five or fewer appendages 

 missing, was almost identical to the growth rate of 

 more seriously injured animals that were missing up 

 to nine legs and both antennae. 



Displacement 



The displacement of undersize rock lobster was 

 also found to significantly affect size increment in 

 each of the three tagging trials. This was probably 

 due to movement of animals from their home range 

 (Chittleborough 1974c) which could have interrupted 

 their normal feeding behavior and thus may have 

 contributed to a decrease in food intake and hence 

 growth. 



Overall Effect 



In general the handling of undersize rock lobsters 

 by fishermen which causes them to be exposed to 

 the atmosphere, damaged and displaced beyond their 

 home range, not only affects their survival (Brown 

 and Caputi 1983) but also affects growth of those 

 that survive As discussed in Davis (1981), this reduc- 

 tion in growth may result in: 



1) The undersize lobsters staying below the legal size 

 for a longer period than necessary with some 

 being subject to natural mortality in this extra 

 period before entering the fishery. 



2) Those animals which do enter the fishery would 

 do so at a reduced size, hence harvestable yield 

 would be reduced. 



572 



