title: Age and growth of Neotrygon picta, Neotrygon annotata and Neotrygon kuhlii from north-east Australia, with notes on their reproductive biology.
abstract: Vertebral band formations were used to define age and growth in three Neotrygon species caught regularly as by-catch in prawn trawl fisheries in north-east Australia. Centrum edge and marginal increment ratio analyses were used to validate annual band formations. Age estimates ranged from 1 to 18 years, with the von Bertalanffy growth function considered to have the best fit to Neotrygon picta (males, W(D∞) = 271 mm, k = 0·12; females, W(D∞) = 360·5 mm, k = 0·08) and Neotrygon kuhlii (males, W(D∞) = 438·6 mm, k = 0·08; females, W(D∞) = 440·6 mm, k = 0·08) disc width (W(D))-at-age data. The Gompertz growth function had the best fit to Neotrygon annotata W(D)-at-age data (males, W(D∞) = 230·4 mm, k = 0·20; females, W(D∞) = 265·5 mm, k = 0·31). Age at sexual maturity ranged from 3 to 6 years, with N. picta having the smallest size at birth (100 mm W(D)), smallest W(D) at 50% maturity (W(D50): male, 172 mm, female, 180·7 mm) and lowest age at sexual maturity (3-4 years). This study helps redefine and improve the accuracy of fisheries-based risk assessments for these small species with relatively conservative life-history variables.
authors.affiliation: School of Biomedical Sciences, University of Queensland, Brisbane, 4072 Queensland, Australia. i.jacobsen@uq.edu.au
authors.forename: I P
authors.initials: IP
authors.lastname: Jacobsen
authors.forename: M B
authors.initials: MB
authors.lastname: Bennett
mesh_terms: D000818:Animals; D049628:Body Size; D018940:Elasmobranchii / Q000254:growth & development*; D005260:Female; D005298:Fertility; D008136:Longevity; D008297:Male; D008954:Models, Biological; D011793:Queensland; D012016:Reference Values; D012098:Reproduction; D012741:Sexual Maturation