786 
Fishery Bulletin 95(4), 1997 
Figure 1 
Study area from Cape Hatteras, North Carolina, to Long Island, New York. 
Dotted and barred areas represent spring and summer sampling areas, 
respectively. 
calculate hatching dates by using validated 
otolith-increment analysis. 
Materiafs and methods 
Collections 
Peprilus larvae and juveniles were collected 
during April and May of 1988 and April of 
1989 in the northern SAB, offshore of Cape 
Hatteras, North Carolina, and June-August 
of 1988 and 1989 in the MAB, from Long Is- 
land, New York, to Cape May, New Jersey 
(Fig. 1; Table 1). 
Fish were collected with a 1-m 2 Tucker 
trawl and a 5-m 2 Frame trawl. The Tucker 
trawl had three opening-closing 505-pm 
mesh nets. Five-minute tows were taken at 
three primary depth intervals: 0-5 m, 5-10 
m, and 10-15 m. For the purpose of this 
study, all depths were combined. The Frame 
trawl was fitted with a 2-mm mesh net and 
towed at the surface for 10 minutes. A flow- 
meter was attached to each net to estimate 
the volume of water sampled. 
Tucker trawl samples were split in half 
with a Folsom plankton splitter. One half of 
each sample was preserved in 5% buffered 
formaldehyde and used for identification and 
length and body depth measurements. The 
other half was preserved in 95% ethanol and 
used for otolith analysis. Frame samples 
were preserved in 95% ethanol. Samples were 
sorted in the laboratory with a dissecting mi- 
croscope for eggs, larvae, and juveniles. 
Morphometries 
Determination of a seasonal difference in body size 
was accomplished by analyzing body depth (BD) and 
standard length (SL) for all specimens collected. 
Measurements were made to the nearest 0.1 mm with 
either a video-enhanced digitizing system (Optical Pat- 
tern Recognition System, BIOSONICS, Inc.) or an ocu- 
lar micrometer. Standard length was measured from 
tip of the snout to the tip of notochord. Body depth was 
measured perpendicular to the longitudinal body axis 
at the anterior margin of the pectoral base (Ditty, 1981). 
To examine differences in body depth between 
spring and summer seasons, linear regressions of 
body depth on standard length were calculated for 
Tucker and Frame cruises, 1988 and 1989. Slopes of 
regression lines were tested for homogeneity. Allom- 
etric effects of growth on body depth were examined 
by calculating regressions of body depth on standard 
length as a function of standard length. 
Meristics 
To determine the species composition of the spring- 
and summer-collected Peprilus larvae, two meristic 
characters were examined: number of caudal verte- 
brae and number of ventral midline melanophores. 
Character counts were compared with published data 
for each of the three possible species (caudal verte- 
brae: Ditty, 1981; ventral midline melanophores: 
Ditty and Truesdale, 1983). Subsamples of specimens 
were either cleared and stained (Taylor, 1967; 
Wassersug, 1976; Dingerkus and Uhler, 1977; 
Potthoff, 1984) or x-rayed (Gosline, 1948; Miller and 
Tucker, 1979; Tucker and LaRoche 1984; Kosenko et 
al., 1987). Photomicrographs of cleared and stained 
specimens were taken and slides developed for further 
