Population genetic structure of Uroteuthis edulis in the East China Sea based on the COI gene

Background: Uroteuthis edulis is a significant economic cephalopod resource utilized by mainland China, Taiwan, and Japan. Understanding the population genetic structure of U.edulis is essential to evaluate the changes of its resource abundance. In this study, we used the COI gene as a marker to evaluate the population structure of U.edulis.

Methods and results: Molecular marker analysis indicated that the sampled individuals were categorized into three populations (ES1, ES2, and ES3). All populations exhibited high haplotype diversity indices (H_d) and low nucleotide diversity indices (P_i), with the ES2 population showing the lowest H_d and P_i values. Analysis of molecular variance (AMOVA) revealed that genetic variation among populations accounted for 89.06% of the total variation. The phylogenetic tree illustrated distinct lineage clustering, with each population forming a separate clade. Combined with the biological information, it was observed that the majority of female individuals were larger in size and exhibited high sexual maturity. Male individuals displayed notable differences across populations: ES1 individuals were primarily small to medium-sized with low sexual maturity, ES2 individuals were mainly medium-sized with a relatively even distribution of sexual maturity, and ES3 individuals were predominantly large-sized with high sexual maturity.

Conclusions: The findings indicate substantial genetic differentiation and ecological variation among U.edulis.

Populations: Strengthen monitoring of population resources and genetic diversity, long-term tracking of changes, and the timely formulation of scientifically sound conservation and management measures to ensure the sustainable development in future.