Caira J N, Rodriguez N, Pickering M
Department of Ecology & Evolutionary Biology, 75 North Eagleville Road, University of Connecticut, Storrs, Connecticut 06269-3043.
J Parasitol. 2013 Oct;99(5):781-8. doi: 10.1645/13-198.1. Epub 2013 May 8.
Two new species of diphyllidean cestodes of the genus Echinobothrium, each hosted by a different skate species in the Raja miraletus complex, are described. Echinobothrium mercedesae n. sp. is described from R. cf. miraletus 2 off Senegal. Echinobothrium yiae n. sp. is described from R. cf. miraletus 1 off South Africa. Both species are small worms that differ from their 29 described congeners in the combination of number of cephalic peduncle spines per column, hook formula, number and arrangement of testes, and arrangement of vitelline follicles. They are easily distinguished from one another in that whereas the vitelline follicles of E. yiae n. sp. are circumcortical, they are lateral in E. mercedesae n. sp., and also in number of cephalic peduncle spines per column (14-17 vs. 10-12). Echinobothrium yiae n. sp. is also unusual in that the cephalic peduncle spines stop short of the anterior margin of the peduncle. In addition, although the paucity of available material precluded their formal description, evidence of 2 additional new species parasitizing R. miraletus also from Senegal is presented. In combination these worms provide support for the interpretation that what is currently recognized as Raja miraletus actually consists of a complex of geographically restricted species, rather than a polymorphic species of multiple parapatric or allopatrically distributed populations. This interpretation is not only supported by previously published molecular data, but also by newly collected morphological data involving differences in the color patterns of disc ocelli among host specimens of the 3 forms available as a result of digital efforts to ensure the accuracy of host identifications, which are also presented here.
描述了棘吻绦虫属的两种新双叶目绦虫，它们分别寄生于米拉莱氏鳐属复合体中的不同鳐类物种。梅赛德斯棘吻绦虫（Echinobothrium mercedesae）新种是从塞内加尔外海的米拉莱氏鳐近似种2中描述的。伊亚棘吻绦虫（Echinobothrium yiae）新种是从南非外海的米拉莱氏鳐近似种1中描述的。这两个物种都是小型蠕虫，在每列头节柄棘的数量、钩式、睾丸的数量和排列以及卵黄滤泡的排列等组合特征上与已描述的29个同属物种不同。它们很容易相互区分，因为伊亚棘吻绦虫新种的卵黄滤泡是围绕皮层的，而梅赛德斯棘吻绦虫新种的卵黄滤泡是位于侧面的，并且每列头节柄棘的数量也不同（14 - 17根与10 - 12根）。伊亚棘吻绦虫新种的另一个不寻常之处在于头节柄棘在柄的前缘之前就终止了。此外，尽管可用材料稀少，无法对它们进行正式描述，但也展示了另外两种同样寄生于塞内加尔的米拉莱氏鳐的新物种的证据。综合来看，这些蠕虫支持了这样一种解释，即目前被认定为米拉莱氏鳐的实际上是一个由地理分布受限的物种组成的复合体，而不是一个具有多个同域或异域分布种群的多态物种。这种解释不仅得到了先前发表的分子数据的支持，还得到了新收集的形态学数据的支持，这些数据涉及通过数字手段确保宿主鉴定准确性后可得的3种形态的宿主标本中圆盘状眼斑颜色模式的差异，本文也展示了这些数据。
