A new species of monorchiid (Digenea) from the South China Sea.

A new species of monorchiid trematode, Leiomonorchis zhanjiangensis n. sp. (Trematoda: Monorchiidae), is described from the intestine of marine fish Secutor ruconius (Hamilton-Buchanan) (Leiognathidae) from Zhanjiang (21°2'N, 110°3'E), Guangdong Province, China. The new species is distinguished from all known species of the genus, mainly by the configuration of vitelline follicles and the shape of excretory bladder (saccular in the new species vs. tubular in the others). According to Madhavi's opinion, Caballerotrematoides secundus Ahmad, 1981 was transferred from Caballerotrematoides Madhavi, 1977 into Leiomonorchis Mamaev, 1970 as L. secundus (Ahmad, 1981) n. comb.