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.鱼类的牙列（dentition）往往极具辨识度，且通常与特定食性紧密相关。梳齿鳚（Combtooth blennies）拥有修长的门齿状口部牙齿，这与绝大多数辐鳍鱼（actinopterygians）截然不同。此前有观点认为，这种修长的牙齿形态是对腐食性（detritivory）的适应性演化，但鉴于其食性的多样性（涵盖腐殖质、珊瑚息肉、多毛类动物以及其他鱼类的组织碎片），鳚科鱼类的牙齿是否真的为单型（monomorphic）结构？抑或是在这种食性分化的背景下，与食性相关的牙齿形态差异依然存在？ 为探究牙齿与食性的分化机制，本研究采用了全新的鳚科（Blenniidae）系统发育假说，对牙齿形态、数量及附着方式进行了量化测量，并对鳚科鱼类的食性开展了定量分析。 鳚类的祖先食性以腐食为主，后续分化出多种食性类群，其中包括完全专性的腐食性类群。本研究结果揭示了一处可能受牙齿形态约束的齿型梯度（dental cline），但这并未阻碍食性的分化进程。 牙齿形态的祖先状态重建（ancestral state reconstruction）结果表明，鳚类的祖先拥有大量无附着型牙齿，随后演化出附着型牙齿数量减少的类群，期间还发生了多次附着型与无附着型牙齿之间的演化反转。 鳚科鱼类的牙列并非单型结构；恰恰相反，其齿列形态多样，牙齿形态的细微变化往往伴随牙齿大小、数量、附着方式的改变，且通常同步发生食性的转变。