Age, growth and maturity of the brown stingray Dasyatis lata
Published online on 09. May 2012
Age, growth and maturity of the brown stingray (Dasyatis lata) around Oahu, Hawai’i
J. J. Dale and K. N. Holland
ABSTRACT:
Baseline data on life-history characteristics of elasmobranchs are often lacking before fisheries exploitation, hindering successful management and conservation of affected species. Age, growth and maturity estimates were determined for the brown stingray, Dasyatis lata, an abundant benthic predator in Hawai’i’s coastal ecosystems, from an unfished population off Oahu, Hawai’i. Age estimates ranged from 0 to 28 years for females and from 0 to 25 years for males. Annual growth-band deposition was verified through marginal increment and centrum edge analysis, as well as recapture of two stingrays marked with oxytetracycline. Multiple growth models were fitted to disk width (DW) and weight-at-age data and evaluated for biological realism and statistical fit. Logistic growth functions best described growth of male and female stingrays, whereas no support was found for von Bertalanffy growth models. Females attained larger sizes (L∞) and exhibited lower growth coefficients (k) than did males. Median size and age at first maturity was estimated to be 104.9 cm DW (15 years) for females and 74.9 cm DW (8.3 years) for males. These life-history characteristics highlight the importance of obtaining baseline data before fisheries are established and indicate that any fishery for brown stingrays should be managed using conservative management strategies.
Marine and Freshwater Research – Online Early Version –