POWELL and GORDY: EGG AND LARVAL DEVELOPMENT OF THE SPOT 



cannot presently be separated from spot, but dis- 

 tinguishing characteristics useful in separating 

 older larvae are well documented (Fruge and 

 Truesdale 1978; Powles and Stender 1978). During 

 late fall and early spring, eggs and early larvae of 

 L. fasciatus and C. nothus could occur with those of 

 spot (Berrien et al. 1978; Powles and Stender 

 1978). The eggs of both these species are unde- 

 scribed, whereas their larvae bear no resemblance 

 to spot larvae (Powles and Stender 1978). 



Meristic characters are useful in separating 

 spot larvae from those of other sciaenids (Table 5). 

 Flexion and older stage spot can be separated from 

 C. nothus, which may be the only species o^Cynos- 

 cion whose eggs and early larvae occur with spot, 

 by total vertebrae counts. Cynoscion nothus has 

 27, rarely 26 vertebrae (high for sciaenids); spot 

 has 25. Beginning at ca. 5 mm SL, spot can be 

 separated from all members of the genus Cynos- 

 cion inhabiting the western North Atlantic by the 

 number of precaudal vertebrae. Cynoscion spp. 

 have more precaudal vertebrae (13-15) than spot 

 (10). 



The arrangement of predorsal bones and 

 pterygiophores can be important in determining 

 phylogenetic relationships (Kendall 1976) and in 

 distinguishing between closely related species 

 (Potthoff 1974; Berrien 1978; Butler 1979). 



Table 5. — Meristic characters useful for separating spot larvae 

 from other sciaenids. Check ( ^ ) indicates nonoverlapping counts, 

 dash ( — ) indicates overlapping counts. Meristics were obtained 

 from cleared and stained specimens. 



'The full complement of anal fin spines and rays was attained at 8.2 mm SL. 

 ^The full complement of dorsal fin spines and rays was attained at 10.8 mm 

 SL 



Pterygiophores are important larval meristic 

 characters, since their full complement is attained 

 before accompanying spines and rays are formed. 

 Since spot have high anal fin ray counts among 

 sciaenids, then anal fin pterygiophore counts 

 would be of utmost importance in separating spot 

 larvae from other sciaenid larvae (Table 5i. 



ACKNOWLEDGMENTS 



We are most grateful to Howard Powles (Envi- 

 ronment Canada, Quebec, Canada) and William 

 R. Nicholson, Southeast Fisheries Center 

 Beaufort Laboratory, National Marine Fisheries 

 Service, NOAA, who reviewed an earlier draft of 

 this manuscript and offered valuable comments 

 and criticism, and to William Hettler (Southeast 

 Fisheries Center Beaufort Laboratory, National 

 Marine Fisheries Service, NOAA) for his valuable 

 contributions to our larval fish rearing program. 

 This research was supported by an interagency 

 agreement between the National Marine 

 Fisheries Service and the Department of Energy. 



LITERATURE CITED 



AHLSTROM, E. H., AND O. P. BALL. 



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APRIETO, V. L. 



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BERRIEN, P. L. 



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713 



