Snowy Grouper Feeding 
107 
not likely recovered with the same regularity as larger foods. Items 
positively identified as bait (squid or cut fish) were not saved. 
Intact stomachs and all loose items were placed in labeled bags on 
ice. At dockside the unusual food items were photographed, and 
then all items were preserved in 10% formalin. 
In the laboratory prey items were rinsed in fresh water and 
were identified. Voucher specimens were transferred to 70% alco- 
hol. Decapods were identified from Williams (1984) and were vali- 
dated by comparison with the Duke University Marine Laboratory 
reference collection. Stomatopod and decapod voucher specimens were 
sent to the National Museum of Natural History for identification 
verification by A. B. Williams and R. B. Manning. Fish were iden- 
tified with the assistance of S. Ross, North Carolina State Univer- 
sity, and G. Burgess, Florida State Museum, Gainesville. Squid were 
identified from Roper et al. (1984). Food items were identified to 
the lowest taxon possible, counted, and measured volumetrically by 
water displacement. Contributions to the diet were calculated as percentage 
by number and as percentage of volume. Except for the few times 
when intact stomach samples were obtained, frequency of occur- 
rence could not be determined. 
RESULTS AND DISCUSSION 
A total of 5,088 snowy grouper was caught from February 
1985 through March 1986. Specimens ranged from 335 to 1,100 
mm in total length (TL). Based on the mass-length relationship 
W = 3.6 x 10' 8 TL 2 868 (where W = mass in kg and TL = total 
length in mm) (Matheson and Huntsman 1984), masses ranged from 
0.6 kg to 19.0 kg (ungutted). We estimate that less than 5% of the 
snowy grouper boated contained food. Presumably most food items 
were regurgitated as the fish were brought to the surface. It is also 
possible that grouper feeding success or effort could have been re- 
duced at specific sites where there were seasonal aggregations of 
hundreds of grouper. Only 23 fish had contents in uneverted stom- 
achs; other items came from regurgitations on deck or were lodged 
in throats or gills. 
All prey items (fish, squid, and crustaceans) had broad latitu- 
dinal distributions and represented a mix of tropical, temperate, and 
boreal affinities. The southerly flowing Virginian coastal current north 
of Cape Hatteras presents a cool-water barrier to established adult 
snowy grouper populations and limits the northerly range of the 
fish and their crustacean prey with tropical affinities (Cerame-Vivas 
and Gray 1966). 
