Morphometric and molecular analyses of Carassotrema koreanum Park 1938 and Elonginurus mugilus Lu 1995 (Digenea: Haploporidae) Srivastava, 1937 from the Russian Far East and Vietnam.

Adult worms that belong to Carassotrema Park 1938 and Elonginurus Lu, 1955 were found in the intestine of Carassius gibelio Bloch, 1782 from the southern Russian Far East and Mugil cephalus Linnaeus, 1758 from northern Vietnam, respectively. Morphometric parameters, geographic location and host species composition of these worms correspond to Carassotrema koreanum Park 1938, which is a known parasite of cyprinid fish in Korea, Japan and China, and Elonginurus mugilus Lu, 1955, first described from M. cephalus in China. The validity of Carassotrema ginezinskajae Kulakova, Ha Ky, 1976, a synonym of C. koreanum, first described from Spinibarbichthys denticulatus Oshima, 1926 in Vietnam, supported the morphometric data. Phylogenetic analysis based on combined ITS2 ribosomal DNA (rDNA) and 28S rRNA indicated that C. koreanum and E. mugilus belong to the subfamily Waretrematinae and are closely related to the genera Skrjabinolecithum and Parasaccocoelium, respectively. Species similarity, revealed through molecular analysis, agreed with the generic diagnoses for Parasaccocoelium and Elonginurus, as well as for Carassotrema and Skrjabinolecithum.