Waindok Patrick, Lehnert Kristina, Siebert Ursula, Pawliczka Iwona, Strube Christina
Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Buenteweg 17, 30559 Hannover, Germany.
Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Werftstr. 6, 25761 Buesum, Germany.
Int J Parasitol Parasites Wildl. 2018 Jan 4;7(1):34-43. doi: 10.1016/j.ijppaw.2018.01.002. eCollection 2018 Apr.
Harbour seals () and grey seals () are final hosts of acanthocephalans in the German North and Baltic Seas. Parasitic infections in seals can cause pathological changes, which may result in deteriorated health of the host. Common gastrointestinal parasites of harbour and grey seals are acanthocephalans and a number of 275 of 2460 (11.2%) investigated seals from 1996 to 2013 were infected with spp. (Acanthocephala, Polymorphidae). The prevalence showed a wave-like pattern: it increased from 1.2% and 0.4% in 1996 and 1997, respectively, to 23.9% during the second phocine distemper epizootic in 2002 and decreased to 6.2% in 2004. In 2005, prevalence peaked again with 25.0% followed by a decrease to 9.3% in 2009 and an increase to 38.5% in 2012. Statistical analysis revealed that harbour seals originating from the North Sea showed a higher prevalence than grey seals, whereas no significant difference between grey and harbour seals from the Baltic Sea was observed. Furthermore, juvenile pinnipedia from the North Sea were significantly less infected with spp. than seals older than seven month. Molecular species identification as well as phylogenetic relationship analysis among the detected species were achieved by sequencing and comparisons of the ribosomal ITS1-5.8S-ITS2-complex and cytochrome-c-oxidase I gene. Molecular analysis resulted in a newly arranged distribution of Acanthocephala in the North Sea as in contrast to previous studies, could not be confirmed as predominant species. Instead, and a isolate (isolate Pv1NS) with an atypical number of longitudinal rows of hooks at the proboscis were detected. Furthermore, morphological and molecular analyses indicate the possible finding of a cryptic species (Candidatus sp. nov.).
港湾海豹（）和灰海豹（）是德国北海和波罗的海棘头虫的终末宿主。海豹的寄生虫感染会引起病理变化，这可能导致宿主健康状况恶化。港湾海豹和灰海豹常见的胃肠道寄生虫是棘头虫，在1996年至2013年调查的2460只海豹中有275只（11.2%）感染了 属（棘头虫纲，多形科）。患病率呈现出波浪状模式：分别从1996年的1.2%和1997年的0.4%增加到2002年第二次海豹瘟热流行期间的23.9%，并在2004年降至6.2%。2005年，患病率再次达到峰值，为25.0%，随后在2009年降至9.3%，并在2012年升至38.5%。统计分析表明，来自北海的港湾海豹患病率高于灰海豹，而波罗的海的灰海豹和港湾海豹之间未观察到显著差异。此外，北海的幼年鳍足类动物感染 属的比例明显低于七个月以上的海豹。通过对核糖体ITS1 - 5.8S - ITS2复合体和细胞色素c氧化酶I基因进行测序和比较，实现了对检测到的 物种的分子物种鉴定以及系统发育关系分析。分子分析导致北海棘头虫的分布重新排列，与之前的研究相比， 不能被确认为优势物种。相反，检测到 以及一种在吻部具有非典型钩纵向排数目的 分离株（分离株Pv1NS）。此外，形态学和分子分析表明可能发现了一个隐存物种（新种暂定名 ）。
