Morphology of the <i>sulcus acusticus</i> in sagittal otoliths and its relationship with mobility patterns in tropical fish species of the families Sciaenidae and Haemulidae

Abstract This study investigates the relationship between sagittal otolith morphology, particularly the sulcus acusticus shape and mobility patterns between two fish families, Sciaenidae and Haemulidae. By analyzing the otoliths of 16 species using geomorphometrics, phylogenetic reconstruction, and multivariate analyses, we explored how the sulcus acusticus shape varies across species with different mobility patterns, evaluating the presence of a phylogenetic signal in this morphological trait. The results showed significant variation in sulcus acusticus shape among mobility groups, but no significant differences between the two families. A weak but significant phylogenetic signal was detected ( K = 0.1668, Z = 11.66, P = 0.001), indicating that evolutionary history contributes slightly to shape variation, though ecological factors, particularly fish mobility, may exert a stronger influence. Species with higher mobility displayed more elliptic and round otolith shapes and a more elongated sulcus acusticus , whereas low‐mobility species exhibited more elliptical shapes with rectangular tendencies. These patterns reflect ecological adaptation to different movement capacities and habitat use. Overall, these findings suggest that while otolith morphology is shaped by evolutionary processes, ecological adaptation plays a dominant role in determining sulcus acusticus morphology, particularly in relation to species' movement, which can be related to habitat use.