REPRODUCTIVE BIOLOGY OF THE VERMILION SNAPPER, 



RHOMBOPLITES AURORUBENS, FROM 



NORTH CAROLINA AND SOUTH CAROLINA 



Churchill B. Grimes* and Gene R. Huntsman* 



ABSTRACT 



The vermilion snapper, Rhomboplites aurorubens, a species often associated with Caribbean reefs and 

 banks, is an important recreational fish of the outer continental shelf of North Carolina amd South 

 Carolina. Serial spawning occurs from late April through September off the Carolinas at depths 

 ranging from 31 to 91 m. Most females spawn in the third or fourth year at about 205-275 mm total 

 length. Larger, older females (age 5-10; up to 530 mm total length) appear to spawn longer each 

 reproductive season, which may be an optimal strategy for maximizing reproductive biomass (balanc- 

 ing the physiological costs of somatic and gonadal growth). 



Overall sex ratio is unequal in favor of females ( approximately 60% ) , but the ratio is 1 : 1 for small fish 

 (less than 150 mm total length) and heavily in favor of large females (69-100?J^ for fish greater than 500 

 mm total length) because they live longer than males. Fecundity of first spawners is estimated at 17-42 

 thousand eggs, and large females produce 1.5 million eggs. 



The vermilion snapper, i?/iom6op/iYesai/rora6ens, 

 is a small lutjanid which grows to 600 mm total 

 length (TL) and 2,600 g (illustrated in Bohlke and 

 Chaplin 1968). It occurs from Cape Hatteras, N.C., 

 to Bermuda, southward throughout the Gulf of 

 Mexico and Caribbean Sea to southeastern Brazil. 

 The species is abundant, ranking second or third 

 in weight and numbers in the Carolina headboat^ 

 fishery (which landed between 590 and 730 metric 

 tons of demersal fishes annually) between 1972 

 and 1975 (Huntsman 1976). 



Vermilion snapper and other reef fishes nor- 

 mally associated with deep (>70-90 m) Caribbean 

 reefs and banks occur in two habitats of the outer 

 continental shelf of the Carolinas (Figure 1). The 

 most spectacular of the habitats, the shelf break 

 zone (Struhsaker 1969), occurs at the edge of the 

 continental shelf (55-180 m) where the gently 

 sloping bottom plunges abruptly downward as the 

 continental slope. It is an area of jagged peaks, 

 precipitous cliffs and rocky ledges associated with 

 drowned Pleistocene reefs (Maclntyre and Milli- 



' Department of Environmental Resources, Cook College and 

 New Jersey Agricultural Experiment Station, Rutgers Univer- 

 sity, New Brunswick, NJ 08903. 



^Southeast Fisheries Center Beaufort Laboratory, National 

 Marine Fisheries Service, NOAA, P.O. Box 570, Beaufort, NC 

 28516. 



^Headboats are recreational fishing vessels which charge 

 anglers for a day's fishing on an individual, thus "per head," 

 basis. 



Manuscript accepted July 1979. 



FISHERIES BULLETIN: VOL. 78, NO. 1, 1980. 



man 1970). The second habitat (inshore live bot- 

 tom) occurs at 25-55 m and consists of broken reefs 

 and rock outcroppings, rocky ledges, and coral 

 patches dispersed over the continental shelf 

 shoreward of the shelf break zone. 



Knowledge concerning reproduction of the ver- 

 milion snapper is lacking. Longley and Hilde- 

 brand (1941) reported gravid specimens about the 

 Tortugas, Fla., in July and concluded that spawn- 

 ing takes place in midsummer. Breder (1929) 

 wTote that vermilion snapper probably spawn in 

 early spring along the South Atlantic coast of the 

 United States, and Walker ( 1950) reported spav^oi- 

 ing off North Carolina in February. Monroe et al. 

 (1973) collected a ripe female off Jamaica in 

 November, and Fahay (1975) and Laroche (1977) 

 recorded larvae off Georgia in July and August. 

 Erdman (1976) found ripe fish from February 

 through June in the northeastern Caribbean. 



In this paper we describe the seasonality, 

 spawning frequency, sex ratio, age and size at 

 maturity, and fecundity of the vermilion snapper 

 and discuss possible adaptive strategies for its re- 

 production. 



The study area (Cape Hatteras, N.C., to Char- 

 leston, S.C.) was stratified by depth (i.e., inshore 

 and offshore, the dividing depth being 55 m), and 

 specimens were collected throughout. Most fish 

 were obtained from the recreational fisheries 

 throughout the Carolinas; however, some speci- 

 mens were collected by hook and line or trawl from 



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