Dutton Haley R, Bullard Stephen A
Southeastern Cooperative Fish Parasite and Disease Laboratory, School of Fisheries, Aquaculture, and Aquatic Sciences, College of Agriculture, Auburn University, Auburn, Alabama 36849.
Unit for Environmental Sciences and Management, North-West University, Private Bag X6001, Potchefstroom, 2520, South Africa.
J Parasitol. 2025 Jul 1;111(4):489-495. doi: 10.1645/25-11.
From July 2021 through June 2024, we necropsied 35 American alligators from Louisiana, Alabama, and South Carolina (including the Gulf of America and Atlantic Ocean river basins). A new polystomatid, Latergater dupreezi n. gen., n. sp. is described based on specimens collected from the eye of 1 wild-caught American alligator measuring 1,450 mm in total length and captured from a salt marsh habitat within the Rockefeller Wildlife Refuge (Grand Chenier, Louisiana) on 19 July 2021. The new species resembles species of Polystomoidinae Yamaguti, 1963 and Oculotrematinae Yamaguti, 1963. It is readily differentiated from species of Polystomoidinae by the combination of having circular haptoral suckers with skeletal elements but that lack marked separation between suckers; ceca having anterior, medial, and lateral diverticula; a compact testis that occupies a small proportion of the intercecal space (vs. a broad testis that spans the intercecal space); a sinistral and intercecal ovary (vs. an ovary that is ventral to the sinistral cecum) having a proximal oviduct extending mediad and then posteriad (vs. proximal oviduct extending anteriad); a small uterus (occupying a minute portion of the intercecal space), medial, and located close to the cecal bifurcation; and vaginal pores that open laterally at the level of or slightly posterior to the level of the testis. It differs from species of Oculotrematinae by having vaginae and lacking hamuli. No other nominal polystome has this combination of features; therefore, the erection of a new genus for the new species is warranted. We lack a nucleotide sequence for the new species because we used the only specimen we collected as a heat-killed, formalin-fixed, stained wholemount (holotype) for a taxonomic study that prioritized morphology. Without a nucleotide sequence (and phylogenetic analysis), we herein refrain from emending an existing subfamily or proposing a new subfamily to accommodate the new genus. This is the first record of a polystome infecting a crocodilian and the first definitive record of an ectoparasitic polystome infecting a host captured in saltwater.
从2021年7月到2024年6月，我们对来自路易斯安那州、阿拉巴马州和南卡罗来纳州（包括美国海湾和大西洋流域）的35只美国短吻鳄进行了尸检。基于从1只野生捕获的美国短吻鳄眼睛中采集的标本，描述了一种新的多盘吸虫，即杜氏后盘吸虫新属、新种。这只短吻鳄全长1450毫米，于2021年7月19日在洛克菲勒野生动物保护区（路易斯安那州大谢尼尔）的盐沼栖息地捕获。该新物种与1963年山口描述的多盘亚科和眼盘亚科的物种相似。它与多盘亚科物种的区别在于：具带有骨骼成分的圆形抱器吸盘，但吸盘之间无明显分隔；盲肠具前、中、侧分支；睾丸紧凑，占据盲肠间空间的一小部分（相比之下，宽睾丸横跨盲肠间空间）；卵巢位于左侧盲肠间（相比之下，卵巢位于左侧盲肠腹侧），近端输卵管向内侧延伸然后向后延伸（相比之下，近端输卵管向前延伸）；子宫小（占据盲肠间空间的一小部分），位于内侧，靠近盲肠分叉处；阴道孔在睾丸水平或略低于睾丸水平处向外侧开口。它与眼盘亚科物种的区别在于具阴道且无小钩。没有其他已知的多盘吸虫具有这种特征组合；因此，为该新物种建立一个新属是合理的。我们没有该新物种的核苷酸序列，因为我们将采集的唯一标本用作热杀死、福尔马林固定、染色的整装标本（模式标本）进行了以形态学为重点的分类学研究。由于没有核苷酸序列（以及系统发育分析），我们在此不修改现有的亚科或提出新的亚科来容纳这个新属。这是多盘吸虫感染鳄鱼的首次记录，也是外寄生多盘吸虫感染在盐水中捕获的宿主的首次明确记录。
