Loefer and Sedberry: Life history of Rhizoprionodon terraenovae off the southeastern United States 



81 



Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun 



Figure 6 



Mean total length by month for embryos collected from April 1997 through 

 March 1999. Numbers indicate sample size for each data point. Error bars 

 represent mean + one standard error 



(Parsons, 1983b; Castro and Wourms, 1993). Early reports 

 of up to 12 pups in sharpnose sharks collected from Cuban 

 waters (Bigelow and Schroeder, 1948) were likely the re- 

 sult of misidentification (Castro and Wourms, 1993). 



Age and growth 



The PCL-CR regression line slightly overestimated cen- 

 trum radius for large individuals. This trend has also been 



noted in large female Carcharhiniis obscurus (Natanson et 

 al, 1995) and appears to result from a change in the slope 

 of the linear relationship as growth becomes asymptotic 

 near the maximum length of the species. This phenomenon 

 was deemed to have a minimal effect on the linear regres- 

 sion formula used in this study. Although the linear rela- 

 tionship appears to undergo an immediate change in slope 

 at about 700 mm PCL. there are not enough data following 

 this change (that is. the animal does not increase substan- 



