Comparison of growth and mortality parameters for purpleback flying squid in different sea areas of the South China Sea

Abstract:

According to the purpleback flying squid (Sthenoteuthis oualaniensis) collected by light attracting falling-net in the South China Sea (SCS) in 2011-2015, the squid individual growth and mortality in the SCS were estimated by Fisat Ⅱ software. The results showed that there were no large individuals in the SCS, and females (12.05 cm) were larger than males (10.91 cm). Growth coefficient b of the squid ranged from 3.470 to 3.605 in the northern sea area and 3.379 to 3.773 in the southern sea area, and there was positive allometry. The growth parameter K indicates that the northern part of the SCS was suitable for the growth of males. The total mortality of the female (1.84) and male (1.76) squids had little difference and the development was relatively uniform in the southern sea area. The total mortality of female squids (0.60) was much less than that of males(4.83) in the northern sea area, so squids here were not fully developed. From the fishery resources development, fishery policies tend to develop the southern squid resources of the SCS, which makes the northern squid resources not fully developed, which is not conducive to the sustainable utilization of the purpleback flying squid resources in the SCS.