NOTE Cordes and Graves: Hyridization and stock structure in Cynosdon regalis 



449 



silver seatrout specimens would have gone unnoticed. This 

 could easily have resulted in a type-II error. Likewise, if 

 nongenetic markers such as otolith microchemistry had 

 been used exclusively, the analyses ofThorrold et al. (2001) 

 would have been based on a mixed-species sample. Instead, 

 it was possible not only to recognize the individuals as 

 anomalous but also to identify them to species and pro- 

 vide evidence of hybridization between at least two of the 

 Cyrioscion congeners. It is hoped that further refinement 

 of the inter- and intraspecific molecular markers developed 

 here and in other studies will eventually be helpful in fur- 

 ther clarifying the taxonomic status, population structure, 

 and possible hybridization within the genus Cynoscion. 



Acknowledgments 



We would like to thank all those who supplied us with weak- 

 fish samples, including Louis Barbieri. Susan Lowerre- 

 Barbieri, Christina Grahn, Patrick Geer, Mike Greene, and 

 Simon Thorrold. We also appreciate the samples of banded 

 drum, gulf kingfish, and star drum provided by Trey Knott 

 and the silver seatrout and sand seatrout specimens pro- 

 vided by Bill Karel. We gratefully acknowledge Kim Reece, 

 John Gold, Linda Richardson, and Robert Chapman for gen- 

 erously providing us with their published and unpublished 

 primer sequences. Funding for this study was provided 

 through the Virginia Marine Resources Commission. 



Literature cited 



Allendort; F. W., and S. R. Phelps. 



1981. Use of allelic frequencies to describe population 

 structure. Can. J. Fish. Aquat. Sci. 38(12):1507-1514. 

 Anonymous. 



1995. Overfished weakfish stock forces closure of federal 

 waters. Fisheries 21:46-47. 



Avise, J. C. 



1992. Molecular population structure and the biogeographic 

 history of a regional fauna: a case history with lessons for 

 conservation biology. Oikos 63:62-76. 



Bain C, J. Lucy, and M. Arendt. 



1998. Virginia game fish tagging program annual report 

 1997. Virginia Marine Resource Report 98-3 (VSG-98- 

 01), 22 p. Virginia Institute of Marine Science. Virginia 

 Sea Grant Marine Advisory Program, College of William 

 and Mary, Gloucester Point, VA. 



Bentzen P., C. T. Taggart, D. E. Ruzzante, and D. Cook. 



1996. Microsatellite polymorphism and the population 

 structure of Atlantic cod tGadus morhua) in the northwest 

 Atlantic. Can. J. Fish. Aquat. Sci. .53 ( 121:2706-2721. 



Bigelow H., and W. Schroeder. 



1953. Fishes of the Gulf of Maine. U.S. Fish and Wildlife 

 Service Fish. Bull. 53, 577 p. 

 Brunner P. C, M. R. Douglas, and L. Bernatchez. 



1998. Microsatellite and mitochondrial DNA assessment of 

 population structure and stocking effects in Arctic charr 

 Salvelmux alpinus (Teleostei: Salmonidael from central 

 Alpine lakes. Mol. Ecol. 7 (2): 209-223. 



Buonaccorsi V. P., K. S. Reece, L. W. Morgan, and J. E. Graves. 



1999. Geographic distribution of molecular variance within 

 the blue marlin {Makaira nigricans): a hierarchical analysis 



of allozyme, single-copy nuclear DNA, and mitochondrial 

 DNA markers. Evolution 53 ( 2 1:568-579. 

 Chapman R. W., G. R. Sedberry, J. C. McGovern, B. A. Wiley, and 

 J. A. Musick. 



1999. The genetic consequences of reproductive variance: 

 studies of species with different longevities. In Life in the 

 slow lane: ecology and conservation of long-lived marine 

 animals. Am. Fish. Soc. Symp. 23:169-181. 



Chow S., and K. Hazama. 



1998. Universal PCR primers for 87 ribosomal protein gene 

 introns in fish. Mol. Ecol. 7:1247-1263. 

 Chow, S., and H. Takeyama. 



2000. Intron length variation observed in the creatine 

 kinase and ribosomal protein genes of the swordfishX;p/zJas 

 gladius. Fish. Sci. 64(3):397-402. 



Cordes, J. F 



2000. Application of genetic markers to provide species iden- 

 tification and define stock structure: analyses of selected 

 marine fishes of the mid-Atlantic bight. Ph.D. diss., 142 p. 

 Virginia Institute of Marine Science, College of William and 

 Mary, Gloucester Point, VA. 



Cordes, J. F., S. L. Armknecht, E. A. Starkey, and J. E. Graves. 



2001. Forensic identification of sixteen species of Chesa- 

 peake Bay sportfishes using mitochondrial DNA restriction 

 fragment-length polymorphism (RFLP) analysis. Estuar- 

 ies 24(1 ):49-58. 



Cowan, J. H., Jn 



1985. The distribution, transport and age structure of drums 



(family Sciaenidae) spawned in the winter and early spring 



in the continental shelf waters off west Louisiana. Ph.D. 



diss., 182 p. Louisiana State University, Baton Rouge, LA. 



Crawford, M. K., C. B. Grimes, and N. E. Buroker 



1989. Stock identification of weakfish, Cynoscion regalis, in 

 the middle Atlantic region. Fish. Bull. 87: 205-211. 

 CSPI-Scanalytics. 



1996. RFLPScan Plus, version 3.0. SCPI-Scanalytics, Bil- 

 lerica, MA. 

 DeVries, D. A., and M. E. Chittenden Jr 



1982. Spawning, age determination, longevity, and mortal- 

 ity of the silver seatrout. Cynoscion nothus. in the Gulf of 

 Mexico. Fish. Bull. 80:487-500. 

 Ditty J. G. 



1989. Separating early larvae of sciaenids from the western 

 North Atlantic: a review and comparison of larvae from the 

 northern Gulf of Mexico off Louisiana and Atlantic coast of 

 the U.S. Bull. Mar Sci. 44:1083-1105. 

 Excoffier L., P. Smouse, and J. Quattro. 



1992. Analysis of molecular variance inferred from metric dis- 

 tances among DNA haplotypes: application to human mito- 

 chondrial DNA restriction data. Genetics 131:479^91. 

 Ginsburg, I. 



1931. On the differences in the habitat and size of Cynoscion 

 arenarius and Cynoscion nothus. Copeia 1931:144. 

 Guo, S., and E. Thompson. 



1992. Performing the exact test of Hardy-Weinberg propor- 

 tion for multiple alleles. Biometrics 48:361-372. 

 Graves, J. E., J. R. McDowell, and M. L. Jones. 



1992. A genetic analysis of weakfish Cynoscion regalis 

 stock structure along the mid-Atlantic coast. Fish. Bull. 

 90:469-475. 

 Hildebrand, H. H. 



1955. A study of the fauna of the pink shrimp (Penaeus duor- 

 arum Burkenroad) grounds in the Gulf of Campeche. Publ. 

 Inst. Mar Sci. 4:169-232. 

 Leclerc, G. M., M. Diaz, and B. Ely 



1996. Use of PCR-RFLP assays to detect genetic variation at 



