Schoelinck Charlotte, Cruaud Corinne, Justine Jean-Lou
UMR 7138 Systématique, Adaptation, Évolution, Muséum National d'Histoire Naturelle, Département Systématique et Évolution, CP 51, 55 Rue Buffon, 75231 Paris Cedex 05, France.
Parasitol Int. 2012 Jun;61(2):356-9. doi: 10.1016/j.parint.2012.01.009. Epub 2012 Feb 3.
Species of the diplectanid monogenean genus Pseudorhabdosynochus are strictly host-specific (specialist), with the exception of P. cyanopodus, which was reported in New Caledonia, South Pacific, from two host species, Epinephelus cyanopodus and E. chlorostigma. We sequenced the COI gene of both host fish species and of their monogeneans. Morphological identification and pairwise distances showed that the two fish species were distinct (difference 6.1-6.6%), but that their monogeneans were not (difference 0-1.5%). A morphological study of sclerotised parts showed that specimens of P. cyanopodus are similar in both fish. Most species of groupers and their associated Pseudorhabdosynochus species are from warm surface waters, but the two groupers E. cyanopodus and E. chlorostigma are usually caught in deep-sea on the outer slope of the coral reef. This suggests that acquisition of a less strict host specificity is an adaptation of P. cyanopodus to deep-sea hosts.
双盘吸虫单殖吸虫属的伪斜带吸虫种类具有严格的宿主特异性（专性寄生），但蓝鳍斜带吸虫除外，该吸虫在南太平洋新喀里多尼亚被报道可寄生于两种宿主鱼类，即蓝鳍石斑鱼和绿点石斑鱼。我们对这两种宿主鱼类及其单殖吸虫的细胞色素氧化酶亚基I（COI）基因进行了测序。形态学鉴定和两两之间的距离显示，这两种鱼类是不同的（差异为6.1 - 6.6%），但它们的单殖吸虫并非如此（差异为0 - 1.5%）。对硬化部分的形态学研究表明，蓝鳍斜带吸虫的标本在这两种鱼类中相似。大多数石斑鱼种类及其相关的伪斜带吸虫种类来自温暖的表层水域，但蓝鳍石斑鱼和绿点石斑鱼这两种石斑鱼通常是在珊瑚礁外坡的深海中捕获的。这表明获得较低的宿主特异性是蓝鳍斜带吸虫对深海宿主的一种适应。
