Makarikov Arseny A, Tkach Vasyl V, Villa Scott M, Bush Sarah E
Institute of Systematics and Ecology of Animals, Russian Academy of Sciences, Siberian Branch, Frunze Str. 11, 630091, Novosibirsk, Russian Federation.
Syst Parasitol. 2015 Jan;90(1):27-37. doi: 10.1007/s11230-014-9528-x. Epub 2015 Jan 4.
Our helminthological examination of murid rodents on Luzon Island, Philippines, revealed a remarkable diversity of Hymenolepis Weinland, 1858. Here we describe two new species based on specimens from murid rodents Rattus everetti (Günther) and Apomys datae (Meyer) collected from Luzon Island. Hymenolepis alterna n. sp. differs from all known species of Hymenolepis in having irregularly alternating genital pores. This feature has not been reported from any previously known member of Hymenolepis. Additionally, Hymenolepis alterna n. sp. also differs from other Hymenolepis spp. in the relative position of both poral and antiporal dorsal osmoregulatory canals which are shifted towards the middle of the proglottis in relation to the ventral canals on both sides of the proglottides, and in having curved or twisted external seminal vesicle, covered externally by a dense layer of intensely stained cells. Hymenolepis bilaterala n. sp. differs from all known species of Hymenolepis in the relative position of both poral and antiporal dorsal osmoregulatory canals, which are shifted bilaterally towards the margins of proglottides in relation to the ventral canals, and in possession of testes situated in a triangle and eggs with very thin outer coat. A total of seven species of Hymenolepis are known from the Philippine archipelago. This total includes the cosmopolitan species Hymenolepis diminuta (Rudolphi, 1819), which was likely introduced to the island with invasive rats. Strikingly, all seven known species occur on the island of Luzon alone. By comparison, only six Hymenolepis spp. are known from the whole Palaearctic and seven from the Nearctic despite a much better level of knowledge of rodent helminths in these zoogeographical regions, as well as vast territories, diverse landscapes and very rich rodent fauna. This suggests that Hymenolepis spp. may have undergone an unusually active radiation in the Philippines. Possible explanations of this phenomenon are discussed.
我们对菲律宾吕宋岛的鼠科啮齿动物进行的蠕虫学检查发现，1858年温兰德发现的膜壳绦虫属具有显著的多样性。在此，我们根据从吕宋岛采集的鼠科啮齿动物埃氏鼠（冈瑟）和达氏姬鼠（迈耶）的标本描述了两个新物种。交替膜壳绦虫新种与所有已知的膜壳绦虫属物种不同，其生殖孔不规则交替排列。这一特征在膜壳绦虫属此前已知的任何成员中均未被报道过。此外，交替膜壳绦虫新种在poral和antiporal背侧渗透调节管的相对位置上也与其他膜壳绦虫属物种不同，相对于节片两侧的腹侧管，它们向节片中部移动，并且具有弯曲或扭曲的外部精囊，外部被一层密集的深染细胞覆盖。双侧膜壳绦虫新种在poral和antiporal背侧渗透调节管的相对位置上与所有已知的膜壳绦虫属物种不同，相对于腹侧管，它们向节片边缘双侧移动，并且拥有位于三角形中的睾丸和具有非常薄外层的卵。菲律宾群岛已知共有七种膜壳绦虫属物种。这一总数包括世界性物种微小膜壳绦虫（鲁道夫，1819年），它可能是随入侵大鼠被引入该岛的。引人注目的是，所有七个已知物种仅出现在吕宋岛上。相比之下，尽管在这些动物地理区域对啮齿动物蠕虫的了解程度更高，以及拥有广阔的领土、多样的景观和非常丰富的啮齿动物区系，但整个古北区仅已知六种膜壳绦虫属物种而新北区已知七种。这表明膜壳绦虫属物种可能在菲律宾经历了异常活跃的辐射。本文讨论了这一现象的可能解释。
