Age and Growth of Shotted Halibut, Eopsetta grigorjewi (Herzenstein, 1890), in the West Sea of Korea

Abstract

To investigate the age and growth characteristics of shotted halibut, Eopsetta grigorjewi, in the West Sea of Korea, the samples were collected using gill nets throughout 2019. A total of 861 specimens (693 females and 168 males) were analyzed. The BW-TL relations were BW = 0.0034TL3.3278 (R2 = 0.8716) for females and BW = 0.0031TL3.3359 (R2 = 0.8860) for males. This analysis revealed that males exhibited a larger growth rate than females (p < 0.05). Notably, the anterior and posterior sections of the otolith displayed an elongated oval shape, exceeding the radius of the dorsal and ventral regions. By examining the correlation between radii in four directions and total length, the highest correlation was observed between the total length (TL) and the ventral radius (R). The evaluation of the relationship between the fish total length and the otolith ventral radiusresulted in an equation of TL = 14.657R + 9.1601 (R2 =0.7081) for females and TL = 15.037R + 5.0265 (R2 = 0.6992) for males (p < 0.05). The formation of annuli occurred annually, consistently in January each year, as discerned through monthly changes in marginal index (MI) values. The von Bertalanffy growth equations from the relationship between the otolith annuli radius and the total length were Lt = 83.6 (1 − exp−0.046(t+4.70)) in females (n = 693, p < 0.05) and Lt = 56.8 (1 − exp−0.078(t+2.16)) in males (n = 168, p < 0.05).