Otolith shape analysis supports three cryptic species in the Stellifer punctatissimus complex (Acanthuriformes: Sciaenidae)

Abstract Sciaenidae species (croakers and drums) are known for specializations in their sensory apparatus, such as otoliths and lateral line. Within this family, some Stelliferinae members remain taxonomically unresolved due to their cryptic aspects and low phenotypic disparities. Stellifer punctatissimus comprises a species complex putatively formed by three species on morphological grounds, but molecular data have indicated only two evolutionary lineages. Herein, we tested the hypothesis that this complex is composed of Stellifer gomezi (GM), S. menezesi (MN), and S. punctatissimus (PC), using the otolith shape and morphology to differentiate them. Seventy-seven sagittal otoliths (GM = 30, MN = 30, PC = 17) were photographed to outline the otolith contour by Elliptical Fourier descriptors. Ten otoliths for each group were used to detect shape variation in the sulcus acusticus through semilandmarks. Differences in otolith shape contour were recorded among the species by PERMANOVA (Pseudo-F = 4.02, df = 2, p摘要 石首鱼科（Sciaenidae）物种（俗称叫鱼、鼓鱼）以其感觉器官的特化特征而闻名，例如耳石（otoliths）与侧线（lateral line）。该科内部分星首鱼亚科（Stelliferinae）类群因具有隐蔽性形态特征且表型差异较低，其分类学地位仍未明确。星点星石首鱼（Stellifer punctatissimus）构成一个物种复合群，传统形态学研究推测其由3个物种组成，但分子数据仅支持2个进化支系。本研究通过耳石形状与形态特征对该复合群的分类假说进行验证，该假说认为此复合群由戈麦兹星石首鱼（Stellifer gomezi，GM）、梅内塞斯星石首鱼（Stellifer menezesi，MN）与星点星石首鱼（Stellifer punctatissimus，PC）构成。本研究共拍摄77枚矢状耳石（其中GM组30枚、MN组30枚、PC组17枚），采用椭圆傅里叶描述子（Elliptical Fourier descriptors）勾勒耳石轮廓；每组选取10枚耳石，通过半地标点（semilandmarks）分析听沟（sulcus acusticus）的形状变异。经置换多元方差分析（PERMANOVA）检测，不同物种间的耳石轮廓存在显著差异（Pseudo-F = 4.02，自由度df = 2，p