Bilong Bilong C F, Nack J, Euzet L
Laboratoire de Biologie Générale, Faculté des Sciences, Université de Yaoundé I, BP 812, Yaoundé, Cameroun.
Parasite. 2007 Jun;14(2):121-30. doi: 10.1051/parasite/2007142121.
A study of monogenean gill parasites from three species of the genus Clarias Scopoli, 1777 (Clariidae), namely Clarias camerunensis Lönnberg, 1895, C. jaensis Boulenger, 1909 and C. pachynema Boulenger, 1903, from the Nyong Basin (Cameroon) revealed the presence of three new monogenean species of the new genus Birgiellus, namely Birgiellus mutatus n. sp. from C. pachynema, B. calaris n. sp. from C. jaensis and B. kellensis n. sp. from C. camerunensis. The genus Birgiellus differs from the genus Quadriacanthus by the morphology of the ventral bar composed of a single piece (two distinct in Quadriacanthus) and the size of the uncinuli IV, which are not much different from the others (longest in Quadriacanthus). Birgiellus calaris differs from B. mutatus by its ventral anchors longer and larger, the morphology of the ventral bar with a short incision between the two branches, and a long and trapezoid handle, the size of the sclerotised structures of the male and female copulatory organs, the larger thickness of the hook in the male accessory piece, the latter having also a heel. Birgiellus kellensis is closer to B. calaris but can be distinguished by the small size of its dorsal and ventral anchors, its transverse bars, male copulatory organ, and the accessory piece, which also has not a heel but a secondary blade. According to the clause 8.5.2 of the International Zoological Code of Nomenclature (1999) the genus Birgiellus and the species B. mutatus and B. calaris, respectively, replace Claridectes, C. clarisa and C. alacris previously described by Birgi (1987), but whose specimens were not deposited in a museum. All the three taxa described exhibit a strict (oioxenous) host specificity.
对来自喀麦隆尼永河流域的三种胡子鲶属（Clarias Scopoli，1777年）鱼类（鲶科），即1895年的喀麦隆胡子鲶（Clarias camerunensis Lönnberg）、1909年的雅氏胡子鲶（C. jaensis Boulenger）和1903年的厚线胡子鲶（C. pachynema Boulenger）的单殖吸虫鳃寄生虫进行的一项研究，发现了新属Birgiellus的三个新单殖吸虫物种，即来自厚线胡子鲶的变异Birgiellus mutatus新种、来自雅氏胡子鲶的卡拉里斯Birgiellus calaris新种和来自喀麦隆胡子鲶的凯伦西斯Birgiellus kellensis新种。Birgiellus属与Quadriacanthus属的区别在于腹杆形态，前者由单一部分组成（Quadriacanthus属为两个不同部分），以及小钩IV的大小，其与其他小钩差异不大（Quadriacanthus属最长）。卡拉里斯Birgiellus与变异Birgiellus的区别在于其腹锚更长更大，腹杆形态在两个分支之间有短切口且柄长呈梯形，雌雄交配器官硬化结构的大小，雄性附属件中钩的较大厚度，后者还有一个跟部。凯伦西斯Birgiellus与卡拉里斯Birgiellus更接近，但可通过其背腹锚、横杆、雄性交配器官和附属件的小尺寸来区分，附属件也没有跟部而是有一个次生叶片。根据《国际动物命名法规》（1999年）第8.5.2条，Birgiellus属以及变异Birgiellus和卡拉里斯Birgiellus物种分别取代了先前由比尔吉（1987年）描述的Claridectes、C. clarisa和C. alacris，但这些标本未存放在博物馆中。所描述的所有三个分类单元都表现出严格的（单宿主专一性的）宿主特异性。
