FISHERIES RESEARCH INSTITUTE,MOA,TAIWAN

The effects of fishing on stock sustainability of most cephalopod species around Taiwan cannot be properly assessed due to the lack of relevant fisheries biology estimates. In this study, two benthic trawling surveys conducted in northern Taiwan were analyzed and previous studies were reviewed to explore fisheries biology estimates of cephalopod species and discuss patterns of allometric growth. The results showed significant differences in the length–weight relationship (LWR) between sexes in Abralia multihamata and Sepia recurvirostra, but not in S. foliopeza, S. lycidus, and S. vossi. The median value of the estimated parameter b of LWR was 2.42, which indicated a tendency toward negative allometric growth of cephalopods around Taiwan. In Uroteuthis species, parameter b was significantly different between sexes. In contrast, only some Sepia species were significantly different between sexes and Sepioteuthis lessoniana did not show any significant differences. However, the size at maturity of a given cephalopod species could not be reliably estimated by its sexual dimorphism in LWR.