Laboratory of Veterinary Parasitology, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea.
Department of Parasitology, School of Medicine and Parasite Research Center, Chungbuk National University, Cheongju, Republic of Korea.
Parasitol Res. 2024 Oct 31;123(11):365. doi: 10.1007/s00436-024-08368-x.
The East Asian finless porpoise, Neophocaena asiaeorientalis sunameri, is an endangered species that inhabits the coastal marine environments of East Asia. In the present study, we investigated the overall infection status of anisakid nematodes in East Asian finless porpoises from three sea sectors off the Korean Peninsula. The genetic diversity and population genetic structure of the identified nematode species were evaluated. The prevalence of all stages of anisakid nematodes collected from the stomach was 57.55% (61 among the 106 porpoises examined), and 16 of the hosts were found to have adult worms. The mean number of infected adults was 211 (± 419.54, 5-1455 per host). Only one species of anisakids, Anisakis pegreffii, was identified from randomly selected worms by molecular approaches. Analysis of the mitochondrial (mt) cox2 partial gene in 50 newly generated sequences of A. pegreffii revealed 24 haplotypes, including 14 new haplotypes. We observed below-average levels of nucleotide diversity and haplotype diversity compared to other seas around the world. The mtDNA cox2 haplotypes of the species in the three Korean sea areas showed no genetic structure, suggesting well-connected gene flow within these areas. This study represents the first record of a definitive host of A. pegreffii in Korean waters, providing important information regarding anisakids genetic diversity in the cetacean species inhabiting limited regions.
东亚江豚，Neophocaena asiaeorientalis sunameri，是一种濒危物种，栖息在东亚沿海海域。本研究调查了朝鲜半岛三个海域东亚江豚体内异尖线虫感染的总体情况。评估了鉴定出的线虫物种的遗传多样性和种群遗传结构。从胃中采集的异尖线虫所有阶段的感染率为 57.55%（106 头江豚中有 61 头），其中 16 头宿主有成虫。感染成虫的平均数量为 211 条（±419.54，每条宿主 5-1455 条）。仅通过分子方法从随机选择的蠕虫中鉴定出一种异尖线虫，即拟阿脑虫（Anisakis pegreffii）。对 50 条新生成的 A. pegreffii 的线粒体（mt）cox2 部分基因进行分析，共发现 24 种单倍型，包括 14 种新单倍型。与世界其他海域相比，我们观察到核苷酸多样性和单倍型多样性均处于较低水平。三个韩国海域的该物种的 mtDNA cox2 单倍型没有遗传结构，表明这些区域内基因流动良好。本研究首次记录了 A. pegreffii 在韩国水域的明确宿主，为栖息在有限区域的鲸类动物体内异尖线虫的遗传多样性提供了重要信息。
