Life history of the Atlantic sharpnose shark off the southeastern United States

The life history of the Atlantic sharpnose shark (Rhizoprionodon terraenovae) was described from 1093 specimens collected from Virginia to northern Florida between April 1997 and March 1999. Longitudinally sectioned vertebral centra were used to age each specimen, and the periodicity of circuli deposition was verified through marginal increment analysis and focus-to-increment frequency distributions. Rhizoprionodon terraenovae reached a maximum size of 828 mm precaudal length (PCL) and a maximum age of 11+ years. Mean back-calculated lengths-at-age ranged from 445 mm PCL at age one to 785 mm PCL at age ten for females, and 448 mm PCL at age one to 747 mm PCL at age nine for males. Observed length-at-age data (estimated to 0.1 year) yielded the following von Bertalanffy parameters estimates: L = 749 mm PCL (SE=4.60), K = 0.49 (SE=0.020), and t sub(0)=-0.94 (SE=0.046) for females; and L=745 mm PCL (SE=5.93), K=0.50 (SE=0.024), and t sub(0)=-0.91 (SE=0.052) for males. Sexual maturity was reached at age three and 611 mm PCL for females, and age three and 615 mm PCL for males. Rhizoprionodon terraenovae reproduced annually and had a gestation period of approximately 11 months. Litter size ranged from one to eight (mean=3.85) embyros, and increased with female PCL.