Wilke T, Davis G M, Gong X, Liu H X
The Academy of Natural Sciences, Department of Malacology, Philadelphia, Pennsylvania 19103, USA.
Am J Trop Med Hyg. 2000 Apr;62(4):453-9. doi: 10.4269/ajtmh.2000.62.453.
The human lung fluke Paragonimus is transmitted by gastropod taxa of two superfamilies: Ceritheoidea and Rissooidea. The question whether or not Paragonimus shows the same specificity of host-parasite coevolved relationship as the human blood fluke Schistosoma was inspired by the finding of two sympatric snail species as hosts for Paragonimus skrjabini in Fujian Province, China: Gammatricula and Erhaia. The former species can clearly be classified as Pomatiopsidae: Triculinae. The latter has previously been classified as Pomatiopsidae: Pomatiopsinae. However, this classification based on anatomical characteristics is uncertain. In order to obtain a robust phylogenetic hypothesis for Erhaia, we have studied three gene fragments from this taxon as well as from twelve related taxa. The data show that the species involved represent four families: Pomatiopsidae, Hydrobiidae, Cochliopidae (here raised to family status), and Amnicolidae. Erhaia fits securely into the Amnicolidae. This indicates that P. skrjabini has not coevolved with snail lineages. However, P. skrjabini has so far only been reported from rissooidean snails, whereas members of the Paragonimus westermani complex have only been found in ceritheoidean snails. The implication is that there is a host specificity on the superfamily level. However, Asian freshwater species of the Ceritheoidea and Rissooidea usually are not sympatric and often prefer different habitats. It is therefore possible that ecological niche partitioning plays the primary role for Paragonimus evolution.
蟹守螺超科和蛹螺超科。中国福建省发现两种同域分布的蜗牛物种——福建拟钉螺和洱海螺可作为斯氏并殖吸虫的宿主，这引发了一个问题：并殖吸虫是否与人体血吸虫一样，呈现出相同的宿主 - 寄生虫协同进化关系的特异性。前者物种可明确归类为黑螺科：拟钉螺亚科。后者此前被归类为黑螺科：瓶螺亚科。然而，这种基于解剖特征的分类并不确定。为了获得关于洱海螺的可靠系统发育假说，我们研究了该分类单元以及十二个相关分类单元的三个基因片段。数据表明，所涉及的物种分属四个科：黑螺科、溪螺科、卷螺科（此处提升为科级地位）和环口螺科。洱海螺稳固地归入环口螺科。这表明斯氏并殖吸虫并未与蜗牛谱系协同进化。然而，迄今为止，斯氏并殖吸虫仅在蛹螺超科的蜗牛中被报道过，而卫氏并殖吸虫复合体的成员仅在蟹守螺超科的蜗牛中被发现。这意味着在超科层面存在宿主特异性。然而，蟹守螺超科和蛹螺超科的亚洲淡水物种通常不同域分布，且往往偏好不同的栖息地。因此，生态位分化可能在并殖吸虫的进化中起主要作用。
