Molecular characterization of three digeneans parasitizing marine fish in the Gulf of Thailand.

Abstract

The Gulf of Thailand is a highly diverse marine ecosystem, yet knowledge of its helminth fauna remains fragmentary. Marine fishes were obtained in 2024 from accidental catches of crab-trap fishers or captured by local fishermen using boats in Chumphon Province, Thailand. In this study, we molecularly characterize three digenean trematode genera parasitizing marine fishes from this area:(Hemiuridae) from the short mackerel (), with a prevalence of 77% in 22 fishes and ten worms examined for morphology;(Lepocreadiidae) from, with a prevalence of 18% in 22 fishes, and from, with a prevalence of 100% in one fish, with 10 worms examined for morphology; and(Lepocreadiidae) from the double-lined tonguesole (), with a prevalence of 75% in four fishes, and eight worms examined for morphology. Sequences of nuclear ribosomal markers (18S, ITS2, and 28S) were generated, providing the first molecular data for. Our analyses confirm the presence ofandsp. in the Gulf of Thailand, contribute new molecular data, and provide a morphological description ofsp. Despite the Gulf of Thailand's high ichthyofaunal diversity, its helminth communities remain insufficiently investigated, highlighting the need for future research.