Chisholm L A, Whittington I D, Morgan J A, Adlard R D
Department of Microbiology & Parasitology, The University of Queensland, Brisbane, Queensland 4072, Australia.
Syst Parasitol. 2001 Jun;49(2):81-7. doi: 10.1023/a:1010629022955.
Partial large subunit 28S rDNA sequences were obtained for specimens of Calicotyle (Monogenea: Monocotylidae) from eight different host species distributed worldwide to test the validity of some species and to address the question of host-specificity in others. Sequences obtained for Calicotyle specimens identified as C. kroyeri based on morphological methods from the type-host Raja radiata (Rajidae) and an additional host R. clavata, both from the North Sea, were identical. However, 'C. kroyeri' from the cloaca of R. naevus from Tunisia, Raja sp. A from Tasmania and R. radula from Tunisia differed from C. kroyeri from R. radiata by five (0.51%), 21 (2.13%) and 39 (3.96%) base pairs, respectively, over 984 sites. Therefore, it is likely that the specimens from Raja sp. A, R. radula and perhaps even from R. naevus are not C. kroyeri. Molecular results determined that the calicotylines from the cloaca of Urolophus cruciatus and U. paucimaculatus (Urolophidae) from southern Tasmania identified previously as C. urolophi are indeed identical. Large subunit 28S rDNA sequences of C. palombi and C. stossichi collected from the cloaca and rectal gland, respectively of Mustelus mustelus (Triakidae) from the coast of Tunisia differ sufficiently for these calicotylines to be considered separate and valid species. Our results indicate that some species of Calicotyle are not strictly host-specific, but that C. kroyeri may not be as widely distributed in rajids as was believed previously. Calicotyle specimens from rajids must be re-examined critically to determine whether there are morphological differences indicative of specific differences that may have been overlooked previously.
从分布于世界各地的8种不同宿主物种中获取了卡里科吸虫属（单殖吸虫纲：单殖科）标本的部分大亚基28S核糖体DNA序列，以检验某些物种的有效性，并解决其他物种的宿主特异性问题。从北海的模式宿主放射鳐（鳐科）和另一宿主棒鳐中，基于形态学方法鉴定为克氏卡里科吸虫的标本所获得的序列是相同的。然而，来自突尼斯的痣鳐泄殖腔中的“克氏卡里科吸虫”、塔斯马尼亚的A种鳐和突尼斯的小齿鳐，与放射鳐中的克氏卡里科吸虫在984个位点上分别相差5个（0.51%）、21个（2.13%）和39个（3.96%）碱基对。因此，来自A种鳐、小齿鳐甚至可能来自痣鳐的标本很可能不是克氏卡里科吸虫。分子结果表明，此前鉴定为泌尿鳐卡里科吸虫的、来自塔斯马尼亚南部的十字形电鳐和少斑电鳐（电鳐科）泄殖腔中的卡里科吸虫属物种确实是相同的。分别从突尼斯海岸的鼬鲨（真鲨科）的泄殖腔和直肠腺中采集的帕氏卡里科吸虫和斯托氏卡里科吸虫的大亚基28S核糖体DNA序列差异足够大，足以将这些卡里科吸虫属物种视为不同的有效物种。我们的结果表明，一些卡里科吸虫属物种并非严格的宿主特异性，但克氏卡里科吸虫的分布可能不像之前认为的那样广泛存在于鳐科鱼类中。必须对来自鳐科鱼类的卡里科吸虫标本进行严格重新检查，以确定是否存在形态差异，这些差异可能表明之前被忽视的物种差异。
