Khawia abbottinae sp. n. is described from the Chinese false gudgeon, Abbottina rivularis (Basilewsky) (Cyprinidae: Gobioninae), from the Yangtze River basin in China. The new species can be distinguished from the congeneric species mainly by the arrangements of the testes, which form two longitudinal bands (other congeneric species have the testes irregularly scattered throughout the testicular region) and their number (at maximum 85 testes versus at least 160 in the other Khawia spp.), and the morphology of the scolex, which varies from cuneiform to widely bulbate scolex, being separated from the remaining body by a short neck and possessing a smooth, blunt or rounded anterior margin. Other typical features of K. abbottinae are its small size (total length less than 1.5 cm) and body shape, with the maximum width at its first third. The distinct status of the new species was confirmed by molecular data (ssrDNA and ITS1 sequences). Phylogenetic analyses revealed a close relationship of the new species with K. rossittensis (Szidat, 1937) and K. parva (Zmeev, 1936), parasites of crucian carp and goldfish (Carassius spp.), but both species markedly differ from K. abbottinae in their morphology. Until now, five valid species of Khawia (K. abbottinae, K. japonensis, K. rossittensis, K. saurogobii and K. sinensis) have been reported from China.
Myxobolus taibaiensis sp. n. was found in the inner intestinal wall of common carp, Cyprinus carpio Linnaeus, during the investigation of fish parasite fauna in Lake Taibai, located in the middle reach of the Yangtze River, China. The whitish ellipsoidal plasmodia, up to 2.9 mm long and 1.7 mm wide, developed in the circular muscle layer of the intestinal wall and produced significant compression into adjacent tissues, but no significant inflammatory responses were observed against this infection. Mature spores are oval in frontal view and lemon-like in lateral and apical view, averaging 10.2-11.2 µm (10.8 ± 0.2 µm) in length, 9.1-9.9 µm (9.6 ± 0.2 µm) in width and 6.1-6.6 µm (6.3 ± 0.1 µm) in thickness. Polar capsules are pyriform, equal in size, slightly converging anteriorly, measuring 4.4-5.4 µm (5.0 ± 0.2 µm) in length by 3.2-3.6 µm (3.4 ± 0.1 µm) in width. Polar filaments coiled with four to five turns and arranged perpendicular to the polar capsule length, measuring up to 106 µm. Myxobolus taibaiensis sp. n. is morphologically similar to Myxobolus rotundatus Achmerov, 1956 which also infects the inner wall of the intestine of common carp. However, the small subunit ribosomal DNA sequence identity was only 94%, generally beyond the intraspecies variation in the genus. Phylogenetically, this new species is sister to M. rotundatus and then clusters with M. shantungensis Hu, 1965 to form an independent common carp-infecting cluster within the Henneguya-Myxobolus clade., Xinhua Liu, Congjie Hua, Qianqian Zhang, Yuanli Zhao, Dong Zhang, Jinyong Zhang., and Obsahuje bibliografii