Meristic and morphometric data for "Revision of the jawfish genus Lonchopisthus with description of a new Atlantic species (Teleostei: Opistognathidae)"

Synonymies, diagnoses, descriptions, illustrations, an identification key and meristic frequency tables are provided for all species of Lonchopisthus. Most of the skeletal anatomy of L. higmani is also illustrated. A new jawfish, Lonchopisthus ancistrus n. sp., is described from the Gulf of Mexico and off Honduras based on 21 specimens 41‒89 mm standard length (SL). It differs from other congeners by the following combination of characters: posterior end of maxilla strongly hooked; membrane connecting maxilla and premaxilla and inner membrane covering posterior part of dentary pale; segmented dorsal-fin rays 11–13, with unbranched rays 2–5; longitudinal body scale rows 33‒39; and very long pelvic fins, 39.4‒75.3 % SL. Lonchopisthus lemur (and its synonym L. meadi) share most characters with L. ancistrus but differ in having shorter pelvic fins, 19.2‒29.9 % SL; fewer longitudinal body scale rows, 26‒33; and five infraorbitals. Both are relatively deep-water species occurring from 100 to at least 375 m, while the other species are found in 3‒139 m. Lonchopisthus micrognathus is unique in having no branched caudal-fin rays at any size and the middle caudal-fin rays with free tips that may be used to maintain tactile contact with the substrate while hovering over its burrow. The western Atlantic Lonchopisthus higmani and eastern Pacific L. sinuscalifornicus are sister species that differ from the other Atlantic species in having the posterior end of the maxilla with a notch instead of a strong hook, opercle with a large dark blotch, and one supraneural (vs. no supraneural).

本数据集为矛颌鱼属（Lonchopisthus）的所有物种提供了同物异名汇总、物种诊断、形态描述、形态图解、分类检索表以及计数性状频率表。同时还对希氏矛颌鱼（Lonchopisthus higmani）的大部分骨骼解剖结构进行了图解展示。本研究基于21尾体长41~89 mm标准体长（standard length, SL）的标本，对采自墨西哥湾及洪都拉斯外海的新种后颌鱼——钩状矛颌鱼（Lonchopisthus ancistrus n. sp.）进行了描述。该新种与同属其他物种的鉴别特征组合如下：上颌骨后缘呈强钩状；连接上颌骨与前上颌骨的膜以及覆盖齿骨后部的内侧膜呈淡色；背鳍分节鳍条11~13枚，不分枝鳍条2~5枚；体纵列鳞33~39行；且腹鳍极长，占标准体长的39.4%~75.3%。狐形矛颌鱼（Lonchopisthus lemur）及其同物异名梅氏矛颌鱼（L. meadi）与钩状矛颌鱼的多数性状相似，但二者腹鳍更短，仅占标准体长的19.2%~29.9%；体纵列鳞更少，为26~33行；且眶下骨为5枚。二者均为较深水物种，栖息深度范围为100 m至至少375 m，而该属其余物种的栖息深度为3~139 m。小颌矛颌鱼（Lonchopisthus micrognathus）的独特之处在于：无论个体大小，其尾鳍均无分枝鳍条，且尾鳍中部鳍条具游离端，该结构可使其在巢穴上方悬停时通过触觉与底质保持接触。西大西洋的希氏矛颌鱼（Lonchopisthus higmani）与东太平洋的加州湾矛颌鱼（Lonchopisthus sinuscalifornicus）为姊妹群，二者与其他大西洋物种的区别在于：上颌骨后缘具缺刻而非强钩状；鳃盖具大型深色斑块；且具1枚上神经骨（其余大西洋物种无上神经骨）。