Abstract Geographic origin authentication is increasingly important for maintaining transparency, product value, and sustainability in fisheries and aquaculture supply chains. Rapid and non-destructive screening tools nevertheless remain limited for high-value crab species. We used principal component analysis (PCA) to evaluate whether image-based geometric morphometrics could discriminate the geographic origin of the horsehair crab Erimacrus isenbeckii (Brandt, 1848). Landmark coordinates were extracted from dorsal and ventral photographs of individuals collected from three major Japanese production regions (Oshamanbe, Kamaishi, and Noto), and analyses were conducted separately by sex and body region. PCA revealed substantial overlap among regions in dorsal carapace morphology for both males and females, indicating limited geographic resolution. Male ventral abdominal morphology also showed weak differentiation. By contrast, female ventral landmarks produced clear separation among regions, suggesting that reproductive morphology captures biologically meaningful geographic variation. These results demonstrate that image-based morphometrics provides a rapid, non-destructive approach for preliminary origin screening. Although morphometric signals may be influenced by physiological factors such as molt stage and body condition, integration with automated imaging and complementary molecular methods could enhance their robustness. Our proposed workflow highlights the potential of image-derived morphometrics as a practical tool for seafood traceability and quality-control systems in fisheries and aquaculture processing pipelines.
Satake et al. (Wed,) studied this question.