This study investigated the identity of 2 lepocreadiid digenean species belonging in the genus Opechona Looss, 1907 that infect littoral fishes of the northern Gulf of Mexico. Opechona chloroscombriNahhas and Cable, 1964, a species previously known only from the Caribbean Sea and the Atlantic Ocean off Brazil, is reported herein from the Atlantic bumper, Chloroscombrus chrysurus (L.), in the northern Gulf of Mexico. A second species infects the gulf butterfish, Peprilus burti Fowler, and the American harvestfish, Peprilus paru (L.), and it is described as a new species that occurs in coastal waters of the north-central and northeastern Gulf of Mexico. Metacercariae infecting the mesoglea of pelagic jellyfishes (Bougainvillia carolinensis [McCady], Chrysaora quinquecirrha [Desor], and Stomolophus meleagris Agassiz) and pelagic comb jellies (Mnemiopsis leidyi Agassiz and Beroe ovata Bruguière) were collected that resemble the new species but require further study to identify. Newly generated sequence fragments (28S rDNA) from both species of Opechona plus 2 other lepocreadiids collected during the study were aligned with publicly available sequences from 18 other lepocreadiids, 6 species of Aephnidiogenidae Yamaguti, 1934, and 2 species of Gorgocephalidae Manter, 1966. The alignment was subjected to Bayesian inference analysis rooted using a gorgocephalid. The resulting tree estimated the positions of both Opechona spp. as being unresolved within a group of taxa that included all available species of Opechona plus available species from the morphologically similar genera ProdistomumLinton, 1910, Preptetos Pritchard, 1960, and Clavogalea Bray, 1985. Although relatively similar in morphology, the 2 studied species of Opechona were surprisingly not closely related. Opechona cablei (Stunkard, 1980) Bray and Gibson, 1990 is herein considered to be a junior synonym of Opechona pyriformis (Linton, 1900) Bray and Gibson, 1990.

这项研究调查了1907 年属于Opechona Looss属的 2 种 lepocreadiid digenean 物种的身份，它们感染了墨西哥湾北部的沿海鱼类。Opechona chloroscombri Nahhas and Cable, 1964 是一种以前仅在加勒比海和巴西附近的大西洋已知的物种，在此报告来自墨西哥湾北部的大西洋丰收区Chloroscombrus chrysurus (L.)。第二个物种感染了海湾鲇鱼 Peprilus burti Fowler 和美国丰收鱼Peprilus paru(L.)，它被描述为一种出现在墨西哥湾中北部和东北部沿海水域的新物种。感染中上层水母（Bougainvillia carolinensis [McCady]、Chrysaora quinquecirrha [Desor]和Stomolophus meleagris Agassiz）和远洋栉水母（Mnemiopsis leidyi Agassiz 和Beroe ovata）的中层蚴，但需要进一步收集新物种确认。来自两个Opechona物种的新生成的序列片段 ( 28S rDNA)加上在研究期间收集的其他 2 个 lepocreadiids 与来自 18 个其他 lepocreadiids、6 种 Aephnidiogenidae Yamaguti，1934 和 2 种 Gorgocephalidae Manter，1966 年的公开可用序列进行比对。使用 gorgocephalid. 对比对进行贝叶斯推理分析。结果树估计了两个Opechona spp的位置。在一组分类群中尚未解决，该分类群包括所有可用的Opechona物种以及来自形态相似的Prodistomum Linton属，1910、Preptetos Pritchard，1960 和Clavogalea Bray，1985 年的可用物种。欧佩乔纳令人惊讶的是没有密切关系。Opechona cablei (Stunkard, 1980) Bray and Gibson, 1990 在此被认为是Opechona pyriformis (Linton, 1900) Bray and Gibson, 1990的初级同义词。