Table 2. Effect of Halimeda metabolites on grazing by (A) 

 parrotfishes (primarily the red band parrotfish 

 Sparisoma aurof renatum ) and (B) the surgeonf ishes 

 Acanthurus bahianus and A^ coeruleus . Assays for 

 parrotfish grazing used Thalassia testudinum as the 

 test plant and were conducted on the reef slope at a 

 depth of 15-18 m. Assays for surgeonfish grazing used 

 Acanthophora spicifera as the test plant and were 

 conducted on the back reef at a depth of 2-3 m. All 

 compound concentrations were at 1% of algal wet mass. 

 14 control-treatment pairs were used for the parrotfish 

 assay and 10 for the surgeonfish assay. We observed 17 

 parrotfish and 12 surgeonfish graze from our plants. 



Contingency Paired Samp. 



# Blades Bitten Table Bites/Blade (x+lSE) t-Test 

 Experimental/Control p-value Experimental/Control p-value 



(A) Parrotfish 



Grazing 7 12 .10>p>.05 0.5+0.2 2.5+0.7 .025>p>.01 



(B) Surgeonfish 



Grazing 3 9 .025>p>.01 2.2+1.3 8.6+2.1 .01>p>.005 



389 



