Two new species of mazocraeid monogeneans from Clupanodon punctatus (Temminck & Schlegel) (Clupeiformes: Clupeidae) found in Daya Bay, South China Sea, with the proposal of Chelimazocraes n. g.

Chelimazocraes liaoi n. g., n. sp. and Chelimazocraes ascidiformis n. sp. (Monogenea: Mazocraeidae) are described from the gills of Clupanodon punctatus (Temminck & Schlegel) in Daya Bay (South China Sea). The new genus is characterised by the following features: (i) the haptor is distinctly separated from the body proper, and the arrangement of the clamps is bilaterally symmetrical but longitudinally heteromorphic; (ii) the anterior three pairs of clamps are of the mazocraeid-type, whereas the fourth pair is of a non-mazocraeid type with three sclerites; (iii) all three pairs of clamps are similar in shape but their size gradually becomes smaller from the anterior to the posterior; (iv) the inner spines of the copulatory organ have a similar shape; and (v) the testes are numerous and arranged longitudinally posterior to the ovary. The two new species are easily distinguished from other members of the Mazocraeidae by the unique structure of the fourth pair of clamps; however, there are some noticeable differences between the two species. The major differences are as follows: (i) the body of C. liaoi n. sp. is significantly larger than that of C. ascidiformis n. sp.; (ii) the anterior three pairs of clamps consist of different sclerites in the two species; and (iii) the copulatory organ has one pair of outer spines and 15-16 pieces of inner spines in C. liaoi n. sp. (vs two pairs of outer spines and 22-26 pieces of inner spines in C. ascidiformis n. sp.).