Caira J N, Jensen K
Department of Ecology and Evolutionary Biology, 75 N. Eagleville Road, University of Connecticut, Storrs, Connecticut 06269-3043, USA.
J Parasitol. 2009 Aug;95(4):924-40. doi: 10.1645/GE-1963.1.
The onchobothriid Triloculatum n. gen. is erected to house species formerly considered members of Phoreiobothrium, but that bear 3, rather than 5 or more, bothridial subloculi. The species formerly known as Phoreiobothrium triloculatum is designated as its type. This species is redescribed based on 2 syntypes and on voucher material consistent with type material taken from the type host, Carcharhinus obscurus, from the type and 1 additional locality. Examination of the cestode fauna of a diversity of carcharhinid sharks resulted in the discovery of an additional 5 new tri-subloculate species belonging to the genus. These include: Triloculatum andersonorum n. sp. from Negaprion acutidens; Triloculatumr bullardi n. sp. from Carcharhinus brevipinna; Triloculatum geeceearelensis n. sp. from Carcharhinus isodon; Triloculatum jodyi n. sp. from Carcharhinus acronotus; and Triloculatum oregontwoae n. sp. from Carcharhinus plumbeus. The new species differ from one another in the number of proglottids, scolex size, number of testes, number of lateral columns of vitelline follicles, and whether they possess craspedote or acraspedote proglottids. Histology and scanning electron microscopy suggest that the new genus differs further from Phoreiobothrium in that its species possess an anterior margin of the posterior loculus that is fused to the anterior loculus, rather than free. The diagnosis of Phoreiobothrium is emended to accommodate the removal of tri-subloculate species and the new information on the condition of the locular interface, and the symmetrical ovary and vitelline follicles arranged in 2 lateral bands; each band consisting of 2 to many columns of follicles. Existing host data indicate that the new genus is restricted to only a subset of the sharks parasitized by species of Phoreiobothrium. Results from the examination of a diversity of carcharhinid species suggest that species in the new genus may have an affinity for the larger, i.e., >200 cm in total length, species of Carcharhinus and Negaprion. One of the new Triloculatum species was found to attach in the crypts lying between the larger ridges found on the mucosal surface of the posterior inner region of the scroll-type spiral intestine of C. brevipinna.
三房室双叶槽绦虫新属（Triloculatum n. gen.）被建立，用于容纳以前被认为是前带双叶槽绦虫属（Phoreiobothrium）成员，但具有3个而非5个或更多双叶槽亚房室的物种。以前被称为三叶前带双叶槽绦虫（Phoreiobothrium triloculatum）的物种被指定为其模式种。基于2个模式标本以及与从模式宿主暗体真鲨（Carcharhinus obscurus）的模式产地和1个其他产地获取的模式材料一致的凭证材料，对该物种进行了重新描述。对多种真鲨科鲨鱼的绦虫动物区系进行检查后，发现了另外5个属于该属的具有3个亚房室的新物种。这些物种包括：来自尖吻斜锯牙鲨（Negaprion acutidens）的安德森三房室双叶槽绦虫（Triloculatum andersonorum n. sp.）；来自短鳍真鲨（Carcharhinus brevipinna）的布拉德三房室双叶槽绦虫（Triloculatumr bullardi n. sp.）；来自伊氏真鲨（Carcharhinus isodon）的盖西阿雷伦西斯三房室双叶槽绦虫（Triloculatum geeceearelensis n. sp.）；来自尖吻真鲨（Carcharhinus acronotus）的乔迪三房室双叶槽绦虫（Triloculatum jodyi n. sp.）；以及来自铅灰真鲨（Carcharhinus plumbeus）的俄勒冈二号三房室双叶槽绦虫（Triloculatum oregontwoae n. sp.）。这些新物种在节片数量、头节大小、睾丸数量、卵黄滤泡侧柱数量以及它们是否具有有边节片或无边节片方面彼此不同。组织学和扫描电子显微镜检查表明，新属与前带双叶槽绦虫属的进一步差异在于，其物种的后房室前缘与前房室融合，而非游离。对前带双叶槽绦虫属的诊断进行了修订，以适应具有3个亚房室物种的移除以及关于房室界面状况的新信息，以及对称的卵巢和排列成2条侧带的卵黄滤泡；每条带由2列至多列滤泡组成。现有的宿主数据表明，新属仅限于被前带双叶槽绦虫属物种寄生的鲨鱼的一个子集。对多种真鲨科物种的检查结果表明，新属中的物种可能与全长大于200厘米的较大型真鲨属和斜锯牙鲨属物种具有亲缘关系。发现新的三房室双叶槽绦虫属物种之一附着在短鳍真鲨卷曲型螺旋肠后内侧区域粘膜表面较大嵴之间的隐窝中。
