Thai medaka, Oryzias minutillus Smith, 1945 (beloniformes: Adrianichthyidae): A new host species of Clinostomum complanatum metacercariae (Digenea: Clinostomatidea) and the surface topography by using SEM

Abstract

The aim of this study was to describe the occurrence of Clinostomum complanatum metacercariae infecting Thai medaka (Oryzias minutillus), a new intermediate host, collected from Pathum Thani province, Thailand. A total of 533 fish collected from 5 localities included 74 infected fish, 10.7% of prevalence, 0.15 of mean abundance and 1.4 of mean intensity for the fluke. The worms were 3.58 mm in length and 0.90 mm in width. The oral suckers were 0.20 mm long and 0.22 mm wide. The ventral sucker was 0.44 mm long and 0.46 mm wide. The surface topography showed structural-systematic features under scanning electron microscopy. This report is the first record of C. complanatum in Oryzias fish and may contribute to the knowledge of clinostomatids, regarding the host diversity and systematic morphology of tegumental trematodes.