Invertebrate Cave Fauna 
107 
8-i 
No. 
Eaten 
4 - 
• • 
-i 1 1 
4 8 16 
No. Offered 
Fig. 36. Functional response of Gyrinophilus porphvriticus larva to 
Caecidotea recurvata. 
Table 4. Occurrence of Caecidotea recurvata , Lirceus usdagalun , and 
Crangonyx antennatus under stones and gravel in areas of strong 
current in Gallohan Cave No. 1 (modified from Estes 1978). The 
first number is the mean 0.09 m ~ and the second is the relative 
density with the highest density for each species given a value of 100. 
Actual stone sizes were not given. 
Species/ Individuals 
Habitat 
Large 
Stones 
Medium 
Stones 
Small 
Stones 
Gravel 
C. recurvata 53 
1.0(28) 
3.63(100) 
1.69(47) 
2.67(74) 
L. usdagalun 412 
7.5(28) 
21.75(82) 
26.62(100) 
16.67(63) 
C. antennatus 13 
0.0(0) 
0.50(38) 
0.62(47) 
1.33(100) 
that relative age of the interaction (as measured by the amount of regres- 
sive evolution and speciation) and competition where negatively correlated 
for Virginia and West Virginia peracarid crustacean communities. 
Species Packing and Species Diversity 
For most of the best-studied communities, species diversity is 
limited by competitive interactions. Culver (1976) showed that competi- 
tion theory predicts a maximum of three species. Three-species com- 
munities in the Greenbrier Valley in West Virginia and in the Powell 
