248 
Aibstracf.-Peiagic larval summer 
flounder, Paralichthys dentatus, were 
collected in the NW Atlantic Ocean 
from 1985 to 1993, and their feeding 
habits were examined in relation to lar- 
val stage. Collections included pre- 
flexion, flexion, premetamorphic, and 
metamorphic larvae, although pre- 
flexion larvae composed the bulk of the 
specimens. Incidence of feeding and 
gut-fullness data indicated that larvae 
began feeding near sunrise and contin- 
ued feeding throughout daylight hours. 
Incidence of feeding reached its lowest 
point, 8.3%, at 0400-0559 hours, then 
dramatically increased to 54.6% at 
0600-0759. Maximum gut fullness was 
seen between 1200 and 1559. The only 
time during which all larvae contained 
prey in their guts was 0800-0959. Im- 
mature copepodites were the primary 
prey for all oceanic larval stages. In 
addition, small prey, such as tintinnids 
and copepod nauplii, made major con- 
tributions to the preflexion diet, and 
large prey, such as calanoid copepods 
and appendicularians, made major con- 
tributions to the diets of premetamor- 
phic and metamorphic larvae. Meta- 
morphic larvae were also collected as 
they entered a New Jersey estuary, at 
night, and their diet was examined. At 
1800-1959 and 2000-2159 hours, the 
incidence of feeding in estuarine larvae 
was significantly lower than in oceanic 
larvae. The estuarine diet was domi- 
nated by the calanoid copepod, Temora 
longicornis. Incidence of feeding was 
observed to decline as metamorphosis 
progressed, from 19.1% at stage G to 
2.9% at stage H. However, this appar- 
ent cessation in feeding, when the right 
eye was at the midpoint of migration, 
may not bring about undue ecological 
peril to summer flounder larvae. 
Manuscript accepted 10 June 1997. 
Fishery Bulletin 96:248-257 (1998). 
Feeding habits of pelagic summer 
flounder, Paralichthys dentatus, 
larvae in oceanic and estuarine habitats 
Jill J. Grover 
College of Oceanic and Atmospheric Sciences 
Hatfield Marine Science Center 
Oregon State University 
Newport, Oregon 97365 
E-mail address: jj.grover@hmsc.orst.edu 
The summer flounder, Paralichthys 
dentatus , an important component 
of recreational and commercial fish- 
eries over the continental shelf and 
in estuaries of the Middle Atlantic 
Bight (United States), is currently 
overexploited. Evidence of this in- 
cludes a drastic reduction in both 
commercial and recreational land- 
ings, in relation to peak years, and 
compressed age structure (Able and 
Kaiser, 1994). Both the fishery’s de- 
cline and efforts to culture summer 
flounder (Bengtson et al., 1994; 
Bengtson and Nardi, 1995) are re- 
viving interest in the basic biology 
of this species. Although much is 
known about the early life history 
of summer flounder, beginning with 
a description of eggs and larvae 
(Smith and Fahay, 1970) and includ- 
ing the timing of spawning, offshore 
distribution of eggs and larvae 
(Smith, 1973; Able et al., 1990), in- 
shore occurrence of larvae and ju- 
veniles (Able et al., 1990), patterns 
of metamorphosis (Keefe and Able, 
1993), and settlement processes 
(Burke et al., 1991; Keefe and Able, 
1994; Norcross and Wyanski, 1994), 
many gaps still exist in our collec- 
tive knowledge of larval and early- 
juvenile ecology. 
Because survival beyond the 
early life history stages is based on 
an “eat and not be eaten” strategy 
(Keenleyside, 1979; Olla and Davis, 
1988; Olla et al., 1994), feeding hab- 
its clearly define much of larval and 
early-juvenile ecology. Recently, lar- 
val summer flounder studies have 
focused on the effects of delayed 
feeding on survival and growth 
(Bisbal and Bengtson, 1995a), de- 
scribing the starving condition 
(Bisbal and Bengtson, 1995b) and 
the development of the digestive 
tract (Bisbal and Bengtson, 1995c). 
Although these studies examined 
natural rates and processes, they 
were all conducted on larvae that 
were reared in a laboratory. Most of 
what is known about the early feed- 
ing ecology of wild summer floun- 
der has been derived from metamor- 
phosing larvae and early juveniles 
that were captured with benthic 
trawls in estuarine nursery habi- 
tats (Burke, 1995). Beyond the 
patent inference that planktonic 
larvae ingest plankton (e.g. Morse, 
1981), very little is known regard- 
ing the early pelagic feeding ecol- 
ogy of this species (Rogers and Van 
Den Avyle, 1983; Grimes et al., 
1989). 
This study considers feeding ecol- 
ogy of larval summer flounder col- 
lected in pelagic habitats in the NW 
Atlantic Ocean from 1985 to 1993. 
Feeding habits were examined in 
relation to larval stage. Metamor- 
phic larvae were also collected as 
they entered an estuarine habitat 
in New Jersey, and their diet was 
examined. 
