Age and Growth of the Spot-Tail Shark in the Taiwan Strait

Age and Growth of the Spot-Tail Shark, Carcharhinus sorrah, in the Taiwan Strait

Joung S-J, Hsu Z-Y, Su K-Y, Liu K-M.

ABSTRACT:

The age and growth of the spot-tail shark, Carcharhinus sorrah, were estimated based on 327 specimens (171 females and 156 males) captured by the coastal/offshore longline or drift net fishery in the waters of the Taiwan Strait from October 2010 to December 2011 and July 2019 to August 2021. Sex-specific whole weight (W)—curved total length (TL) relationships were estimated as follows: W = 7.0 × 10⁻⁶ TL^2.9313 (n = 171, and p < 0.05) for females, and W = 4.0 × 10⁻⁶ TL^3.0516 (n = 156, and p < 0.05) for males. The periodicity of growth band pair (including translucent and opaque bands) deposition in precaudal vertebrae was assumed to be 1 year based on centrum edge analysis and verified by a statistical analysis. The band pairs after the birth mark were counted as 0–5 and 0–8 for females and males, respectively. The Gompertz and von Bertalanffy growth function best described the observed length-at-age data for females and males, respectively. The parameters for sex-specific growth equations were estimated as: L_∞ = 158.6 ± 9.09 cm TL, k_G = 0.2347 ± 0.0245 year⁻¹, and c = −0.3233 ± 0.2043 (n = 171, and p < 0.01) for females, and L_∞ = 170.2 ± 9.51 cm TL, k = 0.1461 ± 0.0182 year⁻¹, and t₀ = −3.1586 ± 0.2065 (n = 156, and p < 0.01) for males.

Marine Science and Engineering. 2022; 10(3):413. DOI: 10.3390/jmse10030413

SOURCE (OPEN ACCESS)