Data from: Extreme dentition does not prevent diet and tooth diversification within combtooth blennies (Ovalentaria: Blenniidae)

The dentition of fishes can be quite striking and is often correlated with a specific diet. Combtooth blennies have long incisiform oral teeth, unlike most actinopterygians. It has been suggested that the long tooth morphology is an adaptation for detritivory, but given the diversity of diets (detritus, coral polyps, polychaetes, and pieces of other fishes), are blenny teeth indeed monomorphic? Or does tooth variation associated with diet still exist at this extreme? To explore tooth and diet diversification, we used a new phylogenetic hypothesis of Blenniidae, measured tooth shape, number, and mode of attachment, and quantified blenniid diet. The ancestral diet of blennies contained detritus and diversified into many different diets, including almost exclusively detritivory. Our results reveal a dental cline that may be constrained by tooth shape, but has not prevented diet diversification. Ancestral state reconstruction of tooth morphologies suggests that the ancestor of blennies had many unattached teeth and featured transitions to fewer attached teeth, with several transitions back to attached or unattached teeth. The dentition of blenniids is not monotypic; rather it is diverse and small changes in tooth shape are accompanied by changes in size, number, attachment, and often diet.

鱼类的齿列往往极具特征，且常与特定食性紧密关联。与多数辐鳍鱼（Actinopterygii）不同，梳齿鳚（combtooth blennies）拥有修长的门齿状口腔齿。此前有研究提出，这类修长的齿形是对食碎屑习性的适应性演化结果，但鉴于其食性的多样性——涵盖腐屑、珊瑚虫、多毛类动物以及其他鱼类的组织碎片——梳齿鳚的齿列果真为单型结构吗？抑或是在这种极端齿形之下，仍存在与食性相关的齿部变异？为探究齿部与食性的多样化演化，本研究采用了全新的鳚科（Blenniidae）系统发育假说，量化测定了齿形、齿数及附着方式，并对鳚科鱼类的食性开展了定量分析。鳚科鱼类的祖先食性包含腐屑类食物，后续演化出多种食性类别，其中甚至存在完全专性食碎屑的类群。研究结果揭示了一处可能受齿形约束的齿形渐变群，但该约束并未阻碍食性的多样化演化。对齿部形态的祖先状态重建结果显示，鳚科鱼类的祖先拥有大量无附着齿，且经历了向附着齿数量减少的演化转变，其间还多次出现附着齿与无附着齿之间的反向转换。鳚科鱼类的齿列并非单型结构；相反，其齿部结构多样，齿形的细微变化往往伴随齿的大小、数量、附着方式的改变，且通常与食性的变化相关联。