636 



Fishery Bulletin 94(4), 1 996 



and spawning frequency more accurately, new tech- 

 niques, such as the hydrated oocyte method for fe- 

 cundity estimates (Hunter et al., 1985) and the 

 postovulatory follicle method (Hunter and Goldberg, 

 1980; Hunter and Macewicz, 1985) for determining 

 spawning frequency, need to be used. There is con- 

 siderable information on the reproductive biology of 

 over 40 lutjanids (Grimes, 1987); however, there is 

 only one recent study (Davis and West, 1993) that 

 uses the new assessment methods on a lutjanid. 



Recent studies of the reproductive biology of ver- 

 milion snapper in the southeastern U.S. are quite 

 limited. Current management of the vermilion snap- 

 per fishery is based on age, growth, and reproduc- 

 tive data collected in the early to mid-1970's, prior 

 to the rapid expansion of the fishery (Grimes, 1978; 

 Grimes and Huntsman, 1980). Grimes (1976) and 

 Grimes and Huntsman (1980) examined aspects of 

 the reproductive biology of vermilion snapper in this 

 area in the early 1970's, but neither used a histo- 

 logical technique to assess reproductive 

 season, spawning frequency, or maturity. 

 Collins and Pinckney ( 1988 ) reported on the 

 maturity of vermilion snapper in the south- 

 eastern United States from 1978 to 1980 but 

 used only scales to age fish. The reproduc- 

 tive biology of vermilion snapper has also 

 been studied in the Gulf of Mexico. Nelson 

 ( 1988 ) examined the sex ratio, size at matu- 

 rity, spawning frequency, and fecundity of 

 vermilion snapper off Flower Garden Banks, 

 Gulf of Mexico, from 1980 to 1982 but did 

 not use a histological technique. These data 

 need to be supplemented with more recent 

 information, including histological criteria 

 and more accurate assessment methods. 



Although vermilion snapper is consid- 

 ered a multiple spawner on the basis of 

 its prolonged spawning season, variation 

 in the gonadosomatic index for similarly 

 sized fish, and variation in the number of 

 maturing ova types found in the ovary 

 (Grimes and Huntsman, 1980), a reassess- 

 ment of the reproductive biology of vermil- 

 ion snapper, using recently developed tech- 

 niques, is necessary 1) to quantify the an- 

 nual reproductive cycle; 2) to determine 

 age and size at maturity and to detect 

 changes that may have occurred because 

 of the fishery; 3) to estimate spawning fre- 

 quency; 4) to describe vermilion snapper 

 as either a determinate or indeterminate 

 spawner; and 5 ) to calculate fecundity (cor- 

 rected for atresia) of the vermilion snap- 

 per in the southeastern United States. 



Materials and methods 



Specimens were obtained between April 1992 and 

 May 1993 on research cruises conducted as part of a 

 fishery-independent survey of reef fishes. Scientists 

 of the MARMAP (Marine Resources Monitoring, As- 

 sessment, and Prediction) program (see Collins and 

 Sedberry [1991] and Zhao and McGovern 1 ) conducted 

 biweekly cruises to randomly selected reef sites, from 

 Cape Lookout, North Carolina, to Jacksonville, 

 Florida (Fig. 1). Sampling in 1992 was conducted 

 from April through August, and in 1993 from May 

 through August by using baited chevron-shaped (ar- 

 rowhead) fish traps (Collins, 1990) soaked for 90 min 

 during daylight only. The time of trap deployment 

 was recorded as time of catch. Some (n=24) fish were 

 collected with hook-and-line gear fished at dawn or 

 dusk (Collins and Sedberry, 1991). Measurements 

 taken from the vermilion snapper catches were 

 lengths in mm (total length [TL] and fork length [FL]) 



