การสำรวจหนอนพยาธิในปลาทรายแดง (Nemipterus spp.) ที่วางจาหน่ายในจังหวัดเชียงใหม่

Abstract

Threadfin bream genus Nemipterus have been high economic values because it is one of the important export products of Thailand. At present, the amount of threadfin bream caught from the Gulf of Thailand has been highly decreasing. The possible cause of this reduction due to parasitic infection affecting fish’s life. From the study of total 100 threadfin breams, 50 Nemipterus hexodon and 50 N. japonicus, between December 2018 to June 2019. In N. hexodon were found 3 species of helminths, including 2 species of Monogenean (Calydiscoides nemipteris and Microcotyle sp.) and 1 species of Nematode (Anisakis typica). While in N. japonicus were found 6 species of helminths including 2 species of Monogenean (C. nemipteris and Microcotyle sp.) 1 species of Trematode (Opecoelus sp.) 2 species of Nematode (Anisakis typica and Camallanus sp.) and 1 species of Acanthocephalan (Rhadinorhynchus cololabis). Total prevalence of the helminths in N. hexodon and N. japonicus were 78% and 66%, respectively. Total intensity were 7.23, 16.36 and total abundance were 5.64 and 10.80, respectively. Morphological study of the Anisakis third-stage larvae by Scanning Electron Microscope demonstrated the mucron at the posterior end were cylindrical shape and molecular study of the larvae by sequencing of the ITS1-5.8S-ITS2 region of ribosomal DNA was confirmed the larvae to be Anisakis typica. Thus, the morphological of the A. typica larvae under SEM in the present study suggested to use as a criterion for classification and the study of diversity of anisakid nematodes in Thailand. As well as the results of the diversity of helminths in threadfin breams sold in Chiang Mai which is ช the first study and report in Chiang Mai, can be used as a database for planning, prevention and reducing the risk of parasitic disease in humans and animals.