Snowy Grouper Feeding 
123 
This might indicate a limit to the size of prey that a snowy grou- 
per can chase down or consume whole. The largest crustacean prey, 
adult Cancer crabs, appeared to be restricted to large fish, those 
greater than 6.8 kg. However, this may be related to the tendency 
of larger grouper to inhabit the 146-228 m depths (Low and Ulrich 
1983) where adult Cancer spp. are located. 
Few fish more than 200 mm TL, and no fish more than 325 
mm TL, were in the diet. This might result not only from an 
inability to swallow large prey whole, but also from an inability to 
pursue large fishes successfully. This stout-bodied, sedentary preda- 
tor might not be able to capture these faster and more maneuver- 
able species. Snowy grouper and tilefish both fed on blackbelly 
rosefish hooked on longlines off South Carolina, yet they were un- 
able to catch this species when observed pursuing it (R. S. Jones, 
Harbor Branch Foundation, Cruise Reports, R/V Johnson, Cruise Number 
J-143 (III) 31 July-10 August 1982). Almaco jack ( Seriola riviolana 
Valenciennes), banded rudderfish ( S . zonata) (Mitchell), and blueline 
tilefish were caught on handlines at the same time as snowy grou- 
per, yet none was observed in stomachs. 
Snowy grouper apparently are not fast swimmers, so it is not 
surprising that demersal decapods dominate their diet. Fast-moving 
fishes tend to be the target of quick, slender-bodied serranids such 
as the Mycteroperca groupers (Table 4). Speed is not a requirement 
for snowy grouper survival. One robust, 2-kg specimen without a 
caudal fin was caught. The blunted caudal peduncle was completely 
healed, and the fish appeared to be in good condition, although 
incapable of rapid propulsion. 
Drift fishing suggests that snowy grouper are so sedentary that 
they will not pursue prey or move more than a few meters to 
intercept moving prey. Grouper locations on the reef sites were 
discrete, and the fish so sedentary that none was caught if the 
vessel missed the fathometer mark by a few meters. Sometimes 
fishermen standing only 7-m apart and using the same bait, gear, 
and fishing technique had drastically different levels of success. If 
only a portion of the vessel was over the mark, the nearest fisher- 
man caught many fish, while others at end of the boat caught few. 
Grouper apparently would not pursue the bait once the lines had 
drifted off the reef. 
Day Versus Night Feeding — More snowy grouper were caught 
in early morning or late afternoon than at midday or night. How- 
ever, night capture of large snowy grouper and the presence of 
nocturnally active prey in their diet suggest that in addition to day- 
light feeding, large E. niveatus feed at night under certain condi- 
