Abstract

To investigate the age and growth characteristics of the pointhead flounder (Cleisthenes pinetorum) in the West Sea (Yellow Sea) of Korea, samples were collected from bottom trawl vessels throughout 2019. A total of 1116 individuals (1015 females and 101 males) were analyzed. Because specimens were obtained from commercial landings, only fish of approximately 20 cm or larger were available due to marketability constraints. The body weight (BW) − total length (TL) relationships were BW = 0.00001TL3.3443 (R2 = 0.9279) for females and BW = 0.000002TL3.2659 (R2 = 0.9347) for males. The observed sex ratio (male:female = 1:10) was strongly female-biased; however, this likely reflected the underrepresentation of smaller males in commercial catches rather than the natural population structure. Females also exhibited larger body lengths than males. Otoliths were generally round, with a slightly elongated anterior region, and measurements were taken along the longest axis from the core to the margin. The relationship between TL and otolith radius (R) was expressed as TL = 8.0342R + 5.6218 (R2 = 0.8408). Growth equations were estimated for both sexes; however, because older males were poorly represented, the male von Bertalanffy growth function was fitted with the asymptotic length fixed to 43.3 cm (110% of the observed maximum male TL). Annuli were formed annually in November, and the spawning season was identified as September–November, suggesting a close association between annulus formation and the spawning period. The von Bertalanffy growth equations were Lt = 57.66(1 − exp[−0.1865(t + 0.46)]) for females and Lt = 43.3(1 − exp[−0.2679(t + 0.5490)]) for males.

IPC Classification

Keywords