Miller Terrence L, Cribb Thomas H
School of Marine and Tropical Biology, James Cook University, PO Box 6811, Cairns, QLD, 4870, Australia,
Syst Parasitol. 2013 Oct;86(2):101-12. doi: 10.1007/s11230-013-9436-5. Epub 2013 Sep 19.
A survey of Indo-Pacific lutjanids of the subfamily Caesioninae revealed the presence of Siphodera gurukun Machida, 1910 and two new cryptogonimid taxa from off Heron and Lizard Islands on the Great Barrier Reef, Australia, Ningaloo Reef, Western Australia and Rasdhoo Atoll, Maldives. A combined morphological and genetic characterisation of these species shows that they form a clade distinct from the type-species of Siphodera Linton, 1910, S. vinaledwardsii (Linton, 1901), and warrants the proposal of a new genus. Here we propose Siphomutabilus n. g. and transfer Siphodera gurukun Machida, 1986 as the type-species, Siphomutabilus gurukun (Machida, 1986) n. comb. Siphodera aegyptensis Hassanine & Gibson, 2005 is transferred to Siphomutabilus as S. aegyptensis (Hassanine & Gibson, 2005) n. comb. based on morphological and ecological similarities. Siphomutabilus raritas n. sp. is described from Caesio cuning (Bloch) off Lizard Island and S. bitesticulatus n. sp. is described from Pterocaesio marri Schultz off Heron Island. The two new species are unique in that they have two testes, making their morphology broadly consistent with that of Metadena Linton, 1910, yet the molecular analyses conducted here indicates that they are unequivocally united with Siphomutabilus gurukun (which has multiple testes) to the exclusion of Metadena lutiani (Yamaguti, 1942), which was sequenced here. The dramatic phenotypic plasticity observed among such closely related species of Siphomutabilus suggests a secondary modification of what is generally considered a robust generic diagnostic character within this and other digenean families, highlighting the need for a combined morphological and molecular diagnostic approach when characterising these taxa. Siphodera Linton, 1910 is amended to include just two species, the type-species S. vinaledwardsii (Linton, 1901) Linton, 1910 and S. cirrhiti Yamaguti, 1970, which are distinguished by their lack of oral spines and multiple testes that are primarily extracaecal. Siphodera ghanensis Fischthal & Thomas, 1968 is considered a species incertae sedis here based on significant morphological and ecological differences compared with species of Siphodera and Siphomutabilus n. g.
对印太裸颊鲷亚科Caesioninae的一项调查显示，发现了1910年的古鲁昆管吸虫（Siphodera gurukun Machida）以及来自澳大利亚大堡礁的赫伦岛和蜥蜴岛附近、西澳大利亚的宁格鲁礁和马尔代夫的拉斯胡环礁的两个新的隐殖科类群。对这些物种进行的形态学和遗传学综合特征分析表明，它们形成了一个与1910年林顿所定的管吸虫属（Siphodera）的模式种——维纳爱德华兹管吸虫（S. vinaledwardsii (Linton, 1901)）不同的进化枝，因此有必要提出一个新属。在此，我们提出新属Siphomutabilus，并将1986年的古鲁昆管吸虫（Siphodera gurukun Machida）作为模式种转移至该属，即古鲁昆可变吸虫（Siphomutabilus gurukun (Machida, 1986)）新组合。基于形态学和生态学上的相似性，2005年的埃及管吸虫（Siphodera aegyptensis Hassanine & Gibson）被转移至可变吸虫属，成为埃及可变吸虫（S. aegyptensis (Hassanine & Gibson, 2005)）新组合。稀有可变吸虫（Siphomutabilus raritas）新种是根据蜥蜴岛附近的库宁裸颊鲷（Caesio cuning (Bloch)）描述的，双睾可变吸虫（S. bitesticulatus）新种是根据赫伦岛附近的马里翼裸颊鲷（Pterocaesio marri Schultz）描述的。这两个新物种的独特之处在于它们有两个睾丸，其形态与1910年林顿所定的后殖属（Metadena）大致一致，但此处进行的分子分析表明，它们明确地与具有多个睾丸的古鲁昆可变吸虫归为一类，而排除了此处测序的卢氏后殖吸虫（Metadena lutiani (Yamaguti, 1942)）。在如此密切相关的可变吸虫物种中观察到的显著表型可塑性表明，这是对通常被认为是该复殖吸虫科及其他复殖吸虫科中一个可靠的属级诊断特征的二次修饰，突出了在对这些类群进行特征描述时采用形态学和分子诊断相结合方法的必要性。1910年的管吸虫属（Siphodera）被修订为仅包括两个物种，即模式种维纳爱德华兹管吸虫（S. vinaledwardsii (Linton, 1901) Linton, 1910）和1970年的卷须管吸虫（S. cirrhiti Yamaguti），它们的特征是没有口棘且多个睾丸主要位于盲肠外。1968年的加纳管吸虫（Siphodera ghanensis Fischthal & Thomas）基于与管吸虫属和可变吸虫新属物种相比存在的显著形态学和生态学差异，在此被视为一个待定物种。
