León-Règagnon V
Center for Historical Ecology and Biodiversity, Department of Zoology, University of Toronto, Ontario, Canada.
J Parasitol. 1998 Feb;84(1):140-6.
Machidatrema n. gen. is proposed to include Neotheletrum frontilatum (Manter, 1969) Gibson and Bray, 1979, Neotheletrum akeh Machida, 1989, Genolinea kyphosi Yamaguti, 1970, and Genolinea chilostoma Machida, 1980. The new genus is characterized by the presence of strong muscles in the anterior part of the body, the hermaphroditic duct divided into 2 sections, prostatic vesicle, and excretory pore in a midventral position. Phylogenetic analysis of the 4 species, based on 14 characters, produced 1 most parsimonious tree with a consistency index of 0.938. The tree suggests that Machidatrema frontilatum and Machidatrema akeh are sister species; Machidatrema kyphosi is the sister species of the former 2, and Machidatrema chilostoma is the sister species of them all. The genus appears to have originated in the Pacific Ocean, parasitizing fishes belonging to Kyphosus; the common ancestor of M. frontilatum and M. akeh appears to have originated by a host-switching event to fishes belonging to Siganus, and M. frontilatum originated by allopatric speciation involving dispersal to the Indo-Pacific and Australia.
新属“真蛭属（Machidatrema）”被提议包含以下物种：“额部新蛭（Neotheletrum frontilatum，曼特，1969年），吉布森和布雷，1979年”、“明田真蛭（Neotheletrum akeh Machida），1989年”、“驼背鲾线虫（Genolinea kyphosi Yamaguti），1970年”以及“唇口鲾线虫（Genolinea chilostoma Machida），1980年”。该新属的特征在于身体前部有强壮的肌肉、雌雄同体的管道分为2段、前列腺囊以及位于腹中线上的排泄孔。基于14个特征对这4个物种进行系统发育分析，得到1棵最简约树，其一致性指数为0.938。该树表明额部真蛭（Machidatrema frontilatum）和明田真蛭（Machidatrema akeh）是姐妹物种；驼背真蛭（Machidatrema kyphosi）是前两者的姐妹物种，而唇口真蛭（Machidatrema chilostoma）是所有这些物种的姐妹物种。该属似乎起源于太平洋，寄生于鲾属（Kyphosus）鱼类；额部真蛭和明田真蛭的共同祖先似乎是通过宿主转换事件起源于蓝子鱼属（Siganus）鱼类，而额部真蛭则是通过涉及扩散至印度 - 太平洋地区和澳大利亚的异域物种形成而产生的。
