REPRODUCTION OF WEAKFISH, CYNOSCION REGALIS, IN 



THE NEW YORK BIGHT AND EVIDENCE FOR 



GEOGRAPHICALLY SPECIFIC LIFE HISTORY CHARACTERISTICS 



Gary R. Shepherd 1 and Churchill B. Grimes 2 



ABSTRACT 



Reproduction characteristics for weakfish, Cynoscion regalis, in the New York Bight were examined. 

 Spawning in 1980-81 occurred from May to early July with spawning time dependent on parental size. 

 Maturity for both sexes occurred by age 1 but at a greater size in females. Annual fecundity estimates 

 were compared with literature values for North Carolina weakfish and were found to be considerably 

 lower at size, yet cumulative fecundities were nearly equivalent. The latitudinal variations in fecun- 

 dity may be a behaviorally and environmentally induced phenomena, and influence the long-term 

 population stability of weakfish. 



Weakfish, Cynoscion regalis, are a member of the 

 family Sciaenidae and are a common inshore 

 species occurring between Cape Cod, Mass., and 

 southern Florida. The species undergoes a spring 

 migration from offshore waters of Virginia and the 

 Carolinas to appropriate estuarine spawning 

 areas, then a return migration in late fall to over- 

 wintering grounds (Nesbit 1954). The center of 

 greatest abundance occurs within the Middle At- 

 lantic Bight in quantities sufficient to support a 

 recreational and commercial fishery. In 1979 

 commercial fishermen landed 13,000 metric tons 

 (t) of weakfish and nearly 5,000 t were caught by 

 recreational anglers (Wilk 1981). Abundance has, 

 however, undergone some dramatic fluctuations 

 over the last several decades. Commercial land- 

 ings averaged 8,800 t from 1940 to 1949, then 

 dropped to 2,915 t by 1950, and remained at these 

 low levels until the mid-1970's (Wilk 1981). The 

 exact cause of these variations remains a mystery, 

 although speculations include overfishing, DDT- 

 induced mortality, and environmentally induced 

 recruitment failure (Massman 1963; Joseph 1972; 

 Merriner 1976). To adequately assess the mecha- 

 nisms controlling recruitment success or failure, 

 we must first have a thorough understanding of 

 the reproductive biology of weakfish. 



Merriner (1976) has examined reproduction of 

 weakfish in North Carolina, and Daiber (1957) 

 mentioned spawning behavior of weakfish in 

 Delaware Bay, but the reproductive biology of 



'Rutgers University, New Brunswick, N.J.; present address: 

 Northeast Fisheries Center Woods Hole Laboratory, National 

 Marine Fisheries Service, NOAA, Woods Hole, MA 02543. 



2 Rutgers University, New Brunswick, NJ 08903. 



weakfish in their northern range has never been 

 fully investigated. Furthermore, there is reason to 

 believe that reproduction may vary throughout 

 the geographic range. Leggett and Carscadden 

 (1978) have shown latitudinal variations in repro- 

 duction and growth of American shad, Alosa 

 sapidissima, and White and Chittenden (1977) 

 have likewise shown geographic differences in 

 another sciaenid, the Atlantic croaker, Micro- 

 pogonias undulatus. Growth differences have al- 

 ready been established for weakfish between the 

 New York Bight and North Carolina (Perlmutter 

 et al. 1956; Shepherd and Grimes 1983), so there is 

 reason to suspect possible reproductive differ- 

 ences. The purpose of the study was to investigate 

 weakfish reproduction in the Middle Atlantic re- 

 gion, to determine if any geographic variations 

 exist, and to consider possible reasons for geo- 

 graphically specific characteristics. 



METHODS AND MATERIALS 



Sample Collection 



Samples {n = 1,208) were collected during the 

 National Marine Fisheries Service (NMFS) 

 groundfish survey from 1980 to 1983 at stratified 

 random stations north of Chesapeake Bay (Fig. 1). 

 Fish were collected with a #41 Yankee trawl in 

 spring and a #30 Yankee trawl in summer and fall 

 at depths between 5 and 200 m (Grosslein 1969). 

 NMFS samples were supplemented by 461 fish 

 collected between May 1980 and June 1981 from 

 commercial pound nets in Gardiners Bay, N.Y, 

 (n = 61) and Sandy Hook Bay, N.J., (n = 115) and 



Manuscript accepted February 1984. 

 FISHERY BULLETIN: VOL. 82, NO. 3, 1984. 



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