An Investigation on the Morphometric Characteristics of the White-Spotted Rabbitfish (Siganus canaliculatus Park, 1797) in the Small Semi-Enclosed Bay Based on Truss Morphometric Methods

The truss morphometric method is increasingly used to study fish's morphometric characteristics between populations in different habitats. The white-spotted rabbitfish (Siganus canaliculatus) is one of the herbivorous fish associated with a variety of habitats of seagrass meadows adapted to its life cycle. This study aimed to compare the morphometric characteristics of S. canaliculatus populations among different habitats of seagrass meadows in Inner Ambon Bay (IAB). Fifty fish samples were measured for morphometric characters using the truss morphometric method taken from four observation stations. Principal component analysis and cluster analysis were used to compare morphometrics characteristics between habitats, and while the distribution of individuals within and between populations uses was assessed using cCanonical dDiscriminant aAnalysis. The results of the PCA analysis obtained three population groupings based on a comparison of morphometric characteristics, with two critical distinguishing characters between populations, namely:"tThe uUpper end of the mouth to the end of the cranial (A1), and the end of the cranial to the beginning of the dorsal fin (B1)". Differences in tidal current distribution patterns in IAB waters and the process of metamorphosis from the pelagic larval phase (pre-settled) to the demersal juvenile phase (post-settled) in different habitats of seagrass meadows are were thought to influence the differences in the characteristics morphometrics of S. canaliculatus between habitats of seagrass meadows. These findings provide valuable information regarding the importance of considering seagrass habitat in supporting fisheries management for sustainable utilization.