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John Dodrill et al. 
tions. When large aggregations were present, fish were caught through- 
out the day. Only after fish were caught repeatedly during multiple 
drifts over a reef would catch rates decline, regardless of time of 
day. 
Snowy grouper generally stopped taking baits at dusk. At depths 
beyond 183 m on calm, moonlit nights single large grouper (>9.1 
kg) sometimes were caught. This contrasts with day catches when 
as many as eight small grouper (<4.5 kg) might take baits within a 
few seconds of each other. 
The disparity in size of day versus night snowy grouper at 
the same station was noted in 194 m on 29 July 1985 SSE of 
Cape Lookout. A randomly measured sample ( n = 44) of specimens 
caught in daylight showed they were of mixed size (range = 465- 
950 mm, mean = 691 mm TL). That night, 37 large snowy grou- 
per were caught at the same station between dark and 0400 hours. 
Fourteen representative specimens were measured revealing a nar- 
rower size range and larger average size (range = 890-990, mean = 
921 mm TL) than those caught during the day. 
Competition — Some other western Atlantic serranids, particularly 
members of the genera Epinephelus, Hypoplectrus , and Serranus have 
been found to prey heavily on crustaceans and less extensively on 
fishes (Parrish 1987). Conversely, Mycteroperca groupers feed al- 
most exclusively on fishes (Table 4). 
At depths beyond 137 m, adult snowy grouper compete to a 
limited degree with other grouper species, which are either uncom- 
mon or absent at these depths. Beyond 137 m only three other 
grouper species were recorded, all epinephelines: E. mystacinus 
(Poey), (E. drummondhayi), and E. Flavolimbatus (Table 2). 
Although the misty grouper ( E . mystacinus ) extends into our 
bathymetric fishing range and deeper in Bahamian, Caribbean, and 
Central American waters (Bohlke and Chaplin 1968; Robins et al. 
1986; L. Davidson, personal communication), it is rare off North 
Carolina. Only two specimens (3-4 kg) were caught in 30 trips 
made in our study. 
Speckled hind (E. drummondhayi) were as uncommon as misty 
grouper although they have been recorded at 130 m or less south 
of our fishing area, at times concurrently with small snowy grouper 
(Huntsman 1976, Manooch 1984). North Carolina and South Caro- 
lina headboats sampled by NMFS revealed only 18 speckled hind 
with food ( n = 168). Half contained fish (53% of all prey items; 
65% of the volume). Decapods composed only 10% of all prey and 
5% of the volume (Duke University Marine Laboratory 1982, Parrish 
1987). 
