Crayfish Population 63 



RESULTS AND DISCUSSION 



Differences in censuses (Table 1) before the 1991 kill and in 

 1994 are not statistically significant (P > 0.1). The increase in crayfish 

 population density immediately after the kill and in 1994 suggests 

 that the population is recovering. However, 1994 censuses in the Peacock 

 III tunnel indicate that populations have not recovered to pre-kill 

 levels along transects 7 and 8. Transect 8a, which encompassed transects 

 7 and 8 as well as an additional 100 m of cave passage, contained 

 only a fraction of the number of crayfish that were present along 

 transects 7 and 8 before the kill. This indicates that the large crayfish 

 population found in the Peacock III tunnel before the kill is not 

 recovering, nor is the overall population in the cave system. 



Of the 138 crayfish censused after the 1991 kill, only one 

 animal was smaller than 1.5 cm. Although animals smaller than 1.5 

 cm in total length may be missed during censusing, the scarcity of 



Table 1. Census data for Procambarus pallidus in the Peacock Springs, 

 Florida, cave system before the 1991 kill, immediately after the kill, 

 and in 1994. 







Numbe 



r of 



crayfish counted 















Immediately after 









Before 1991 

 x S.D. 



kill 

 n 





1991 



X 



kill 



1994 





Transects 



n x 



S.D. 



n 



1 



1.0 



1.0 



3 









1 1.0 





1 



2 



6.5 



0.5 



2 









1 1.0 





2 



2a 1 



not 



counted 











1 9.7 



5.4 



3 



3 



1.5 



0.5 



2 









1 7.0 





1 



4 



4.0 



0.0 



3 









1 0.0 



0.0 



2 



5 



1.0 



0.0 



4 









1 1.0 





1 



6 



6.2 



0.8 



5 









1 6.0 



1.0 



2 



7 



34.5 



2.7 



8 









1 0.0 



0.0 



8 



8 



49.5 



7.1 



8 









1 0.0 



0.0 



8 



8a 1 



not 



counted 











1 10.1 



6.6 



8 



These transects were established after the 1991 kill to cover a larger area than 

 original transects. 



