Vaz Diego F B, Goatley Christopher H R, Tornabene Luke
Natural History Museum, London, UK.
School of Ocean and Earth Science, University of Southampton, Southampton, UK.
J Morphol. 2025 Mar;286(3):e70039. doi: 10.1002/jmor.70039.
Eviota and Sueviota are two genera of cryptobenthic fishes of the family Gobiidae commonly known as dwarfgobies, that collectively contain 142 species. Despite thorough descriptions of the variation of their external morphology, little is known about variations on their skeleton. Combining traditional clearing-and-staining technique with computed scanning microtomography, we examined five species of Sueviota and 40 species of Eviota, representing the two major monophyletic groups in the latter genus, the "branched clade" and "unbranched clade," named for their pectoral ray morphology. The purpose of this study was to provide generalized descriptions for both genera and highlight potentially phylogenetically informative characters that will aid in future classification of this diverse assemblage of fishes. The posterior portion of the mesethmoid was found to be unossified in eight species of Eviota from the unbranched clade. Twenty-five vertebrae (vs. 26 vertebrae) are present only in species of the unbranched clade of Eviota, and it is considered another potential synapomorphy for this clade. Direct contact between the retroarticular and the anterior edge of the interopercle without the retroarticular-interopercle ligament occurs in all species of Eviota and Sueviota, being interpreted as a potential synapomorphy grouping these two genera. The posterior edge of the interopercle is notched in all species of Eviota and Sueviota, as well as in the closely related genera Bryaninops, Pleurosicya, and Paragobiodon. In species of Sueviota and the branched clade of Eviota, the notch is deep, and there is an additional posteroventral process, forming a wrench-like posterior edge of the interopercle. This wrench-shaped interopercle is a potential synapomorphy, grouping Sueviota with representatives of the branched clade of Eviota. Individual and ontogenetic variations are discussed, including an assessment of the characters previously proposed for characterizing the branched and unbranched clades of Eviota.
埃氏侏鮨属（Eviota）和苏氏侏鮨属（Sueviota）是虾虎鱼科（Gobiidae）的两个隐栖底栖鱼类属，通常被称为侏儒虾虎鱼，总共包含142个物种。尽管对它们外部形态的变异进行了详尽描述，但对其骨骼变异却知之甚少。我们将传统的透明和染色技术与计算机扫描显微断层成像相结合，研究了苏氏侏鮨属的5个物种和埃氏侏鮨属的40个物种，后者代表了该属的两个主要单系类群，即“分支类群”和“非分支类群”，它们以其胸鳍鳍条形态命名。本研究的目的是为这两个属提供一般性描述，并突出潜在的系统发育信息特征，这将有助于对这一多样的鱼类组合进行未来的分类。在来自非分支类群的8种埃氏侏鮨中，发现筛骨中部的后部未骨化。仅在埃氏侏鮨的非分支类群物种中存在25块椎骨（相比之下，其他类群为26块椎骨），这被认为是该类群的另一个潜在共有衍征。在所有埃氏侏鮨属和苏氏侏鮨属的物种中，关节后骨与间鳃盖骨前缘直接接触，没有关节后骨 - 间鳃盖骨韧带，这被解释为将这两个属归为一组的潜在共有衍征。在所有埃氏侏鮨属和苏氏侏鮨属的物种以及与之密切相关的布莱恩侏鮨属（Bryaninops）、侧带虾虎鱼属（Pleurosicya）和副虾虎鱼属（Paragobiodon）中，间鳃盖骨的后缘有缺口。在苏氏侏鮨属和埃氏侏鮨属的分支类群物种中，缺口很深，并且有一个额外的后腹侧突起，形成了间鳃盖骨类似扳手的后缘。这种扳手形状的间鳃盖骨是一个潜在的共有衍征，将苏氏侏鮨与埃氏侏鮨属分支类群的代表归为一组。文中讨论了个体和个体发育变异，包括对先前提出的用于表征埃氏侏鮨分支类群和非分支类群的特征的评估。
