Age and growth parameters of the Panamic stingray (Urotrygon aspidura): supp. table 1

Abstract

Mathematical formulas and abbreviations of the individual growth models adjusted to the estimated age data for Panamic stingrays (Urotrygon aspidura). The parameter DW ∞ is the theoretical asymptotic size, representing the average disc width at age that individuals in a stock would attain if they grew indefinitely. The parameter k 1 is the relative annual growth rate, which is a curvature parameter determining the rate at which a stingray reaches the asymptotic size at age and which decreases linearly with DW, and t 1 is the theoretical age at zero, which defines the initial condition on the time axis when mean DW at age is zero. The parameter k 2 is the annual rate of exponential decrease of the relative growth rate (λ) with age, and t 2 is a parameter corresponding to (lnλ−lnk 2 )/k 2 . The parameter k 3 is the relative annual growth rate, and t 3 is the inflection point of the sigmoidal curve. The parameter t h is the age at which the transition between the 2 phases occurs (inflection point), and h is the maximum difference in size at age between the von Bertalanffy and two-phase growth models at the t h . The parameter DW o is the mean DW at birth (fixed at 7.5 cm for models with 2 and 4 parameters).