ASPECTS OF THE REPRODUCTIVE BIOLOGY OF THE WEAKFISH, 

 CYNOSCION REGALIS (SCIAENIDAE), IN NORTH CAROLINA^^ 



John V. Merriner^ 



ABSTRACT 



The weakfish, Cynoscion regalis, has an extended spawning season in North Carohna's inshore waters 

 (males are ripe March to August, and females are ripe April to August). Peak spawning activity occurs 

 from late April through June. The extended spawning season throughout the range is a major factor in 

 variability of size within a year class. 



Published accounts cite attainment of sexual maturity at age II for males and age III for females. I 

 conclude that weakfish of both sexes reach sexual maturity as yearling fish, although some smaller 

 members of a year class do not mature until their second year. 



Weight and length of weakfish are better indicators of fecundity than is age (higher correlation 

 coefficients). A female weakfish of 500 mm standard length produces slightly over two million eggs. 



The weakfish, Cynoscion regalis, is a littoral 

 species of commercial and sport importance in the 

 middle Atlantic states from North Carolina to 

 New York (Bigelow and Schroeder 1953). Welsh 

 and Breder (1923), Higgins and Pearson (1928), 

 Hildebrand and Schroeder (1927), Hildebrand 

 and Cable (1934), Pearson (1941), Roelofs (1951), 

 and Harmic (1958) described portions of the re- 

 productive biology of weakfish. The most recent 

 data concerning reproductive biology of this 

 species in North Carolina were in Hildebrand and 

 Cable (1934). 



The decline in commercial catch of weakfish be- 

 tween 1945 and the mid-1960's and speculation as 

 to its cause(s) (Roelofs 1951; Perlmutter 1959; 

 Fahy 1965a, b; Brown and McCoy 1969; Joseph 

 1972) indicated the need for a biological study of 

 the weakfish along the Atlantic coast (Nesbit 

 1954; Perlmutter et al. 1956; Massmann et al. 

 1958). I undertook a study of the weakfish in 

 North Carolina (1967-70) to provide biological 

 data from which recommendations for manage- 

 ment could be formulated. This paper presents 

 data on reproduction of weakfish pertaining to: 

 1) spawning season, 2) age and size at which sex- 

 ual maturity is attained, 3) fecundity relation- 

 ships, and 4) possible role of reproductive biology 

 in the observed population decline along the east- 

 ern seaboard. 



'Adapted from part of a thesis submitted in partial fulfill- 

 ment of the requirements for Ph.D. in the Zoology Department, 

 North Carolina State University, Raleigh, NC 27607. Financial 

 support was provided by the Sport Fishing Institute. 



2 Virginia Institute of Marine Science Contribution No. 699. 



^Virginia Institute of Marine Science, Gloucester Point, 

 VA 23062. 



Manuscript accepted July 1975. 



FISHERY BULLETIN: VOL. 74, NO. 1, 1976. 



MATERIALS AND METHODS 



A total of 3,635 weakfish were obtained for 

 biological examination from the area bounded by 

 Cape Hatteras and Cape Fear, N.C. Landings of 

 pound nets, haul seines, gill nets, and shrimp 

 trawls in the vicinity of Cape Hatteras, between 

 June 1967 and November 1969, contributed 1,606 

 specimens (Figure 1). An additional 2,029 weak- 

 fish were obtained between June 1967 and 

 January 1970 from trawler landings in Morehead 

 City and Beaufort, and from haul seines landing 

 in Atlantic and Sea Level (Figure 1). 





MORTH 

 CAROLINA 



HATTERAS 



« CAPE LOOKOUT 



CAPE FEAR 



re" 00' 



78 » 00' 



FIGURE 1. — Location of sampling sites included in 1967 to 

 1970 collections of weakfish from North Carolina waters. 



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