Otolith Morphometric and Shape Distinction of Three Redfin Species under the Genus Decapterus (Teleostei: Carangidae) from Sulu Sea, Philippines

Otoliths are paired calcified structures in the inner ear of teleosts that function hearing and balance. In this study, use otolith morphometrics shape analysis were explored to delineate redfin species under genus Decapterus from Sulu Sea, Philippines, namely, kurroides, D. smithvanizi, tabl. Results showed mean shapes unique within (p < 0.001). The size-related (OW—otolith weight, OL—otolith length, OH—otolith height, OA—otolith area, OP—otolith perimeter) shape-related (RE—rectangularity, SQ—squareness, EL—ellipticity, RO—roundness, AR—aspect ratio, FF—form factor, CO—compactness, CI—circularity) morphometric indices also significant variations 0.001) among three species. Distinct regions differentiating kurroides other two seen along dorsal margin otoliths, which was supported by its significantly higher values for OH (size-related index) RO (shape-related index). addition, 0.001), except RE. Furthermore, it revealed able separate species, turned out be indifferent. results provided relevant data on otoliths as an additional confirmatory tool delineation identified and, therefore, offer opportunities applying same method eventually, identification genera, especially those closely resemble each other.