2 
Fishery Bulletin 110(1) 
fication than had been previously attainable (Marancik 
et al., 2010). With these newly identified larvae, our 
purpose here is to describe the spatial and seasonal 
distribution patterns of 15 species (whose larvae could 
be identified) and four multispecies groups (whose lar- 
vae could not be identified to species but which share 
similar physical attributes). Specifically, our objectives 
were to describe 1) the spawning season; 2) locations of 
spawning; 3) environmental factors associated with lar- 
val grouper habitat; and 4) decadal-scale variability in 
the distribution and habitat use of grouper larvae. Our 
work is focused on grouper larvae 
from the Straits of Florida and the 
I 
northern Gulf of Mexico. 
26°N 
Materials and methods 
Collections 
Samples were collected as part of 
two separate sampling programs: 
one across the Straits of Florida 
and one in the northern Gulf of 
Mexico. 
30°N 
27°N 
24° N 
21 °N 
18°N 
96°W 
Straits of Florida A 17-station 
transect crossing the Straits of 
Florida at 25.5°N was sampled 
as part of a larval billfish (Istio- 
phoridae and Xiphiidae) project 
conducted by researchers at the 
University of Miami, Rosenstiel 
School of Marine and Atmospheric 
Science. Samples were collected at 
the beginning of each month from 
January 2003 through Decem- 
ber 2004 (Fig. 1A). The transect 
extended from the Florida shelf 
break to the Great Bahama Bank. 
The three easternmost and three 
westernmost stations were approxi- 
mately 2 km apart; the remaining 
stations were approximately 5.5 km apart. Samples were 
collected with an asymmetrical MOCNESS (multiple 
opening-closing net and environmental sensing system) 
consisting of a 4-m 2 frame with 1000-pm mesh nets and 
a 1-m 2 frame with 150 -pm mesh nets (Guigand et al., 
2005). The MOCNESS sampled in 25-m depth bins from 
0-50 m at the westernmost station or 0-100 m at deeper 
stations. Surface waters (0-0.5 m) were sampled with a 
combined neuston net composed of a 1x2 m mouth with 
1000-pm mesh net and a 1x0. 5-m mouth with 150-pm 
mesh net. Samples were collected between sunrise and 
sunset, and the entire transect was generally sampled 
within a 48-hour period. At least 16 of the 17 stations 
were successfully sampled on all but three cruises; 
weather limited sampling in December 2003, January 
2004, and November 2004. Samples were immediately 
preserved in 95% ethanol and, after 2-5 days, were 
92°W 
88°W 
84°W 
80°W 
Figure I 
Map of sampling regions showing (A) an expanded view of the transect stations 
across the Straits of Florida, and (B) the northern Gulf of Mexico Southeast 
Area Monitoring and Assessment Program (SEAMAP) sampling stations 
and east Florida shelf transect. SEAMAP stations are coded by season: 
X=April-May, triangles = September-Oetober, and cireles=winter southern 
Gulf of Mexico sampling. The 100-m and 200-m isobaths are also shown. 
transferred to 70% ethanol for long-term storage. Llopiz 
and Cowen (2008) and Richardson et al. (2010) provide 
further details of the Straits of Florida sampling survey. 
In the laboratory, all larval fish were removed from 
all neuston samples, samples collected in 2003 with 
both the 1-m 2 and 4-m 2 MOCNESS, and samples col- 
lected in 2004 from only the 4-m 2 MOCNESS. Genetic 
sequencing of the cytochrome oxidase subunit I gene (as 
in Richardson et al., 2007) was used to identify a subset 
(approximately 40%) of the Straits of Florida grouper 
larvae to species (Marancik et al., 2010). The remaining 
larvae were either identified to species or grouped with 
morphologically similar species according to physical 
attributes (Marancik et al., 2010). Body length and 
developmental stage were recorded for each fish. De- 
velopmental stage refers to the upward (dorsal) flexion 
of the notochord tip (urostyle) concurrent with caudal 
