裂腹鱼指环虫(Monogenea:Dactylogyridae)一新记录种

文章记述了采自新疆伊犁河流域巩乃斯段的新疆裸重唇鱼(Gymnodiptychus dybowskii Kessler, 1874)和斑重唇鱼(Diptychus maculates Steindachner, 1866)鳃部寄生的指环虫属(Dactylogyrus)一新种。通过传统方法及分子生物学方法研究确定了两种宿主寄生的虫体为同一种。该虫体与同宿主寄生的Dactylogyrus driagini(Bychowsky, 1936)和寄生于伊犁裂腹鱼的Dactylogyrus longicopula(Bychowsky, 1936)略为相似,但在交接器和后吸器形态上有较大差异:其交接器的支持器部分,分为上下两部分,在连接处形成"Y"状结构, D.driagini支持器为完整一体的结构,而D. longicopula支持器的连接处为卷曲状结构;后吸器形态:拟定种与D.driagini, D. longicopula后吸器均由一对中央大钩、7对边缘小钩和两联结片组成,其中央大钩内、外突不明显,边缘小钩明显区分钩尖、钩柄和柄轴,钩尖和钩柄交接处无刺状突起, D. driagini中央大钩内、...

A NEW SPECIES OF DACTYLOGYRUS, D. DIPTYCHUS N. SP. (MONOGENEA: DACTYLOGYRIDAE), FROM SCHIZOTHORACINE FISHES (CYPRINIDAE: SCHIZOTHORACINAE) IN THE XINJIANG UYGUR AUTONOMOUS REGION,CHINA

This paper describes a new species of the genus Dactylogyrus parasitizing the gills of Gymnodiptychus dybowskii (Kessler, 1874) and Diptychus maculates (Steindachner, 1866) collected from the Gongnesi section of the Yili River Valley, Xinjiang Uygur Autonomous Region. By using traditional and molecular biological methods, the newly discovered species was confirmed as a parasite of these two hosts and was found to be somewhat similar to the parasitic species Dactylogyrus driagini (Bychowsky, 1936) and Dactylogyrus longicopula (Bychowsky, 1936). Significant differences in the morphology of the copulatory complex and the opisthaptor were observed. The supporting portion of the crossover is divided into upper and lower parts. A “Y” structure of the D. driagini support is formed at the junction, while the connection of the D. longicopula support exhibited a curly structure. Regarding the shape of the opisthaptor, those of the proposed species and D. driagini and D. longicopula are composed of a pair of central hooks, seven pairs of marginal hooks and two connected bars. The inner and outer root processes of the central hooks are not obvious, and the marginal hooks are obviously distinguishable by the hook tip, the hook handle and the handle axis. There is no spiny process at the junction of the hook tip and the hook stalk, and the lobulation of the inner and outer root processes of the D. driagini central hook is very obvious; however, the differentiation of the marginal small hook is not obvious, while the lobulation of the inner and external processes of the central hook of D. longicopula is very obvious, and the inner process is much larger than the external process. There is a spiny process at the junction of the tip of the small hook and the handle of the hook. The abdominally connected bars are thick and short, the middle portion shows peak uplift, the two ends of the D. longicopula abdominally connected bars are slender, and the middle portion shows triangular uplift. Based on the sequence alignment analysis of Dactylogyrus 18S-ITS1-5.8S rDNA, the similarity to the cryptic species Dactylogyrus cryptomeres (Bychowsky, 1934) is highest, at 92.0% similarity. The phylogenetic tree also showed that the species clusters with D. cryptomeres with a confidence of 100 (BI/ML), but taking its morphological characteristics, host habitat and host specificity, this species is not the cryptic species D. cryptomeres. Based on the results of morphological structural analysis and molecular phylogeny, the identified Dactylogyrus parasite can be considered a new species, which is designated Dactylogyrus diptychus n. sp. according to the host characteristics.