Buckel and Conover: Movements, feeding, and daily ration of Pomatomus saltatrix 
671 
Time (h) 
Time (h) 
Figure 4 
Gut-fullness values (mean ± SE) of spring-spawned bluefish, Pomatomus saltatrix, 
versus time of capture during 1993 diel beach-seine collections. (A) Mean gut full- 
ness (± SE) averaged across all dates of collection: (B) 7-8 July, (C) 20-21 July, (D) 
4-5 August, and (E) 18-19 August 1993. The time periods from sunset to sunrise 
are indicated by dark horizontal bars. Numbers above each gut-fullness estimate 
represent bluefish sample size. Upward and downward facing arrows represent the 
time of high and low tide, respectively. 
Estimates of daily ration in 
1993 were not statistically dif- 
ferent from each other. Daily 
ration of summer-spawned fish 
on 19-20 September 1992 was 
5.7% body weight/d (2. 6-9. 4). 
Diet analysis 
Diets of YOY bluefish collected 
with beach seines during 1992 
and 1993 were dominated by 
fish. Fish prey represented 97- 
100% of bluefish diet by weight 
(Table 1 and 2). 
In 1992, the diet ofYOY blue- 
fish was dominated by clupeids, 
moronids, and bay anchovy 
Anchoa mitchilli (Table 1). Clu- 
peids (American shad, blueback 
herring [. Alosa aestivalis ], ale- 
wife [ Alosa pseudoharengus ], 
and Alosa spp. — clupeids that 
could not be identified to spe- 
cies) were the dominant prey of 
1992 bluefish collected by beach 
seine and were found in 30% of 
stomachs containing prey and 
represented 27% of bluefish 
prey weight (Table 1). Striped 
bass, white perch, Morone amer- 
icana, and Morone spp. (mor- 
onids that could not be identified 
to species) were found in 19% of 
bluefish stomachs and made up 
27% of their diet by weight. Bay 
anchovy were an important 
component of the diet on 19-20 
Sept, representing 47% of the 
diet by weight (41 %F). Atlantic 
silversides, Menidia menidia, 
and Atlantic tomcod, Micro- 
gadus tomcod , were found in 
bluefish diets during August 
and September. Invertebrates 
(zoeae, copepods, and sand 
shrimp) were a small compo- 
nent of bluefish diet (Table 1). 
In 1993, the diet ofYOY bluefish was dominated 
by striped bass, bay anchovy, and Atlantic silversides 
(Table 2). Striped bass was the dominant prey ofYOY 
bluefish in 1993 beach-seine collections, i.e. in 22% 
of bluefish stomachs and accounting for 37% of their 
diet by weight. Bay anchovy was also a major prey of 
bluefish in 1993 (11%F, 22% Wj, particularly during 
the July collections. The Atlantic silverside became 
an important prey in August (Table 2). As in 1992, 
invertebrates were a small component of bluefish 
diet. 
Striped bass ( 11 %F, 35% W) and Atlantic silversides 
(24%F, 21%W) were dominant prey items ofYOY 
bluefish captured with the gill net in 1993 (Table 3). 
