until 45 yr later. Rivas (1954) mentioned the 

 weakfish in the gulf but provided no specific data. 

 Hutton et al. (1956) reported C. regalis from Boca 

 Ciega Bay at St. Petersburg, Fla., but Springer 

 and Woodburn (1960) listed only C. arenarius 

 from Tampa Bay. No specimens of C. regalis from 

 the gulf are in the reference fish collection of the 

 Department of Natural Resources at the St. Pe- 

 tersburg Marine Laboratory (Moe et al. 1966). 



Two adult C. regalis (266 and 298 mm standard 

 length) were captured by personnel from the 

 Marco Ecology Laboratory in the vicinity of Marco 

 Island, on the southwest coast of Florida on 21 July 

 1972 (Florida State University Fish Collection, 

 catalog number 24023). The documentation of the 

 weakfish in the Gulf of Mexico together with the 

 extremely close morphological and biochemical 

 characteristics shared by C. regalis and C. are- 

 narius suggest that gene exchange between the 

 Atlantic Ocean and gulf coast populations is 

 feasible although we have no proof of their inter- 

 breeding. Nevertheless, the evidence points to the 

 same series of events which characterize the 

 evolutionary history of other marine geminate 

 species in Florida. When the peninsula split the 

 ancestral population into two, the Gulf population 

 differentiated from that in the Atlantic (see 

 Ginsburg 1952; Walters and Robins 1961). 

 Whether or not isolation was complete or only 

 partial, the present distribution indicates that at 

 least one form (C. regalis) has been successful 

 in moving around the tip of the peninsula into 

 southeastern gulf waters and in establishing 

 secondary contact with the other (C. arenarius). 

 The status of C. arenarius should be investigated 

 in depth. Perhaps an extensive enzyme study 

 would be appropriate, the results of which could be 

 compared by statistical analyses (Avise 1974) to 

 determine the level of differentiation between two 

 forms. 



ACKNOWLEDGMENTS 



The authors extend their thanks to the many 

 individuals who aided in collection of seatrout, 

 particularly Robert Stickney of the Skidaway 

 Institute, Skidaway Island, Ga., and Rufus Messer 

 of Carrabelle, Fla. Our work was supported in part 

 by the Florida Department of Natural Resources; 

 we thank Edwin Joyce for his support and 

 encouragement. 



FISHERY BULLETIN; VOL. 74, NO. 3 



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