FIGURE 1. Mean numbers of fishes observed on 

 different types of reefs. All 5 guilds are 

 included in total fishes. Species included in 

 these guilds are listed in Appendix Table 1. 

 The A reefs (open squares) are comprised of 

 cinderblocks and rubble, the B reefs (closed 

 squares) are built of cinderblocks only, 

 and the C reefs (stars) are made of rubble 

 only. For purposes of illustration, error 

 bars are omitted here, but they are included 

 in Reaka, 1981, 1983. 



INVERTEBRATE- 

 EATERS 



July Aug Sep Oct Nov Dec Jan 



'80 



CENSUS DATE 



'81 



required for full colonization 

 of the new rubble habitat by 

 invertebrates (Reaka, 1981, 

 1983). In all guilds, fishes 

 on the C reefs generally were 

 smaller than those on the 

 cinderblock reefs (Wolf, 

 Bermingham, et a]_. , unpub. 

 data) . 



The data in Figure 1 sug- 

 gest that reefs with habitat 

 for invertebrates (A) generally 

 were characterized by higher 

 numbers of fishes than reefs 

 without habitat for inverte- 

 brates (B). Specifically, the 

 number of invertebrate-eaters 

 per reef was significantly 

 higher on A reefs than on B 

 reefs in August and October, 

 and the data showed a strong 

 tendency in that direction in 

 November (Mann Whitney U tests; 

 p< 0.02, p<0.01 , and p<0.058, 

 respectively). In addition, the 

 total numbers of invertebrate- 

 eaters per census on the 5 

 type A reefs were consistently 

 higher than those recorded on 

 the 5 type B reefs for the 6 

 month interval (Wilcoxon 

 matched-pairs signed-ranks 

 test, p <0.01). 



Population levels of inver- 

 tebrates may be affected by 

 invertebrate-eaters that prey 

 upon reef residents, and by 

 planktivorous fishes that eat 

 invertebrate larvae swimming 

 near or settling on the reef. 

 The total numbers of inverte- 

 brate-eating fishes per census 

 on the 5 type A reefs were 

 consistently higher than those 

 on the 5 type C reefs through- 

 out the study period (Wilcoxon 

 matched-pairs signed-ranks 

 test, p < 0.01). However, 

 there was no significant 

 difference in the numbers of 

 planktivorous fishes per cen- 

 sus on A vs. C reefs over the 

 6 month interval (Wilcoxon 

 matched-pairs signed-ranks 

 test, n.s.). The number of 



71 



