Aquaculture and Sea-Ranching, Faculty of Agricultural and Environmental Sciences, University of Rostock, Justus-von-Liebig-Weg 6, 18059, Rostock, Germany.
German Oceanographic Museum Foundation, Katharinenberg 14-20, 18439, Stralsund, Germany.
Acta Parasitol. 2021 Mar;66(1):26-33. doi: 10.1007/s11686-020-00246-7. Epub 2020 Jul 8.
Endoparasitic nematodes of six harbour porpoises Phocoena phocoena and four grey seals Halichoerus grypus, stranded at the eastern coast of the Baltic Sea in Germany in winter 2019, were analysed in order to identify nematode parasites and to compare with recent studies from the same area.
Endoparasitic nematodes were identified by using both morphological and molecular characters. The successfully obtained sequences of the rDNA marker regions ITS-1, 5.8S, ITS-2 from 29 anisakid and the rDNA marker region ITS-2 of 11 pseudalid nematodes were amplified.
Analyses revealed the presence of three parasite species, the anisakid nematode Contracaecum osculatum from grey seals and the pseudalid nematodes Pseudalius inflexus and Stenurus minor from the harbour porpoises. Other anisakid nematodes regularly occurring in the Baltic Sea, e.g. Anisakis simplex or Pseudoterranova decipiens, were not found.
The prevalence of 100% and a severe parasite load in grey seals demonstrated a very high C. osculatum infection of Baltic Sea fish as their regular prey. Prevalence of 33% for parasites in harbour porpoises and minor infection rates, combined with a distinct lack of anisakid nematodes, are typical for the current situation of the porpoise parasite fauna in the Baltic Sea. Invasive parasite species as possible indicators for climate change could not be detected.
分析于 2019 年冬季在德国波罗的海东部海岸搁浅的 6 头港湾鼠海豚（Phocoena phocoena）和 4 头灰海豹（Halichoerus grypus）体内的寄生性内寄生虫，以鉴定寄生虫种类，并与该地区近期的研究进行比较。
采用形态学和分子特征对寄生性内寄生虫进行鉴定。成功扩增了 29 条异尖线虫和 11 条伪新棘虫 rDNA 标记区 ITS-1、5.8S、ITS-2 的 rDNA 标记区 ITS-2 的部分序列。
分析结果显示存在 3 种寄生虫，分别为灰海豹体内的异尖线虫 Contracaecum osculatum 以及港湾鼠海豚体内的伪新棘虫 Pseudalius inflexus 和 Stenurus minor。在波罗的海常见的其他异尖线虫，如 Anisakis simplex 或 Pseudoterranova decipiens 并未发现。
100%的感染率和灰海豹体内严重的寄生虫负荷表明，波罗的海鱼类作为灰海豹的常规食物，其体内 C. osculatum 感染非常严重。港湾鼠海豚寄生虫感染率为 33%，感染程度较低，且缺乏异尖线虫，这是波罗的海鼠海豚寄生虫区系当前状况的典型特征。没有发现可能指示气候变化的入侵性寄生虫物种。
