Marancik et al.: Spatial and temporal distribution of grouper larvae in the Gulf of Mexico and Straits of Florida 
15 
All grouper Small grouper 
Small spinelet group Long curved spinelet group 
Mycteroperca spp. Graysby 
Year 
Figure 7 
Interannual patterns in percent frequency of occurrence of the six most abundant 
taxa of grouper larvae collected in the northern Gulf of Mexico during Southeast 
Area Monitoring and Assessment Program spring (white bars) and fall (black bars) 
surveys. Spring data was constrained to stations at depths <900 m. 
a few specimens were collected during April and May 
in deep offshore Gulf of Mexico waters (Fig. 4A). These 
larvae were morphologically identical to the larvae col- 
lected on the shelf; therefore misidentification is unlike- 
ly. Unlike the fall-spawned graysby, the spring-spawned 
graysby were collected in neuston nets (surface <0.5 m) 
and at stations with water temperatures warmer than 
surrounding stations (data not shown), indicating an 
association with Loop Current water that is transported 
north from the Caribbean Sea into the eastern Gulf of 
Mexico. These specimens may have been spawned lo- 
cally and entrained in a Loop Current eddy or may have 
originated south of the study area (Campeche Bank or 
Caribbean Sea) and been carried north. Either way, 
these larvae represent an expanded spawning season 
(April-October) not previously recorded in the literature. 
Similarly, spawning season determined through ob- 
servation of adult red grouper in the Gulf of Mexico was 
limited to January-March (Johnson et al., 1998, Brule 
et al., 1999). A significant number of red grouper lar- 
vae from the Straits of Florida sampling were captured 
in May, indicating a spawning season extending from 
January to May. Burgos et al. (2007) collected spawning 
females from mid February to mid June in North and 
South Carolina — a period coinciding with the timing of 
our collection of larvae. 
Spatial occurrence 
Grouper larvae, in general, have a narrow distribution 
pattern regardless of water properties such as tempera- 
ture and salinity. Grouper larvae were collected along 
