Rohner Simon, Boyi Joy Ometere, Artemeva Valentina, Zinke Olaf, Kiendl Astrid, Siebert Ursula, Lehnert Kristina
Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Werftstrasse 6, 25761 Buesum, Germany.
Museum der Westlausitz Kamenz, 01717 Kamenz, Germany.
Pathogens. 2023 Apr 13;12(4):587. doi: 10.3390/pathogens12040587.
Arthropod ectoparasites of aquatic wildlife often have complex relationships with their host species that have developed over long evolutionary time scales. Specialist parasite occurrence might depend on these hosts' distributions. Eurasian otter () populations are recovering in Northern German federal states, such as Schleswig-Holstein and Lower Saxony. Chewing lice (; Ischnocera; Mallophaga) are considered otter-specific yet rare parasites in their known range. In 2022, they were recorded for the first time on nine otters found dead in Northern Germany. All otters originated from the years 2021-2022 and were dissected during population health monitoring programs in 2022. Females ( = 6) were 0-5.5 years old and showed signs of disease in five cases. Males ( = 3), in contrast, were 0-1.6 years old and showed disease in a single case. Individual lice intensity of infection ranged from 1 to 75 specimens per otter. No direct adverse health effects of chewing lice on the otters were noted. morphological characteristics were documented and measurements were taken to study specialized adaptations that allow lice to attach to semi-aquatic otters. In addition, morphology was compared between lice from different geographical regions and specimens from previous reports. A region of the COI mDNA was amplified to molecularly characterize for the first time and detect genetic differences between otter lice populations in Germany. It is believed that specialist parasites reduce in numbers even before their host populations decline. Recovering otter populations in Northern Germany could be an example of a reverse effect, where the comeback of a host species results in the return of a specialist parasite, which reflects an ultimate boost in overall species biodiversity.
水生野生动物的节肢动物外寄生虫与其宿主物种之间往往存在着在漫长进化时间尺度上形成的复杂关系。专性寄生虫的出现可能取决于这些宿主的分布情况。在德国北部联邦州，如石勒苏益格 - 荷尔斯泰因州和下萨克森州，欧亚水獭（ ）种群正在恢复。咀嚼虱（ ；食毛目；毛虱科）在其已知分布范围内被认为是水獭特有的但较为罕见的寄生虫。2022年，在德国北部发现的9只死亡水獭身上首次记录到了这种寄生虫。所有水獭均来自2021 - 2022年，并且是在2022年的种群健康监测项目中进行解剖的。雌性（ = 6）年龄在0 - 5.5岁之间，其中5例有疾病迹象。相比之下，雄性（ = 3）年龄在0 - 1.6岁之间，仅有1例有疾病迹象。每只水獭身上的单个虱子感染强度在1至75个标本之间。未观察到咀嚼虱对水獭有直接的不良健康影响。记录了虱子的形态特征并进行了测量，以研究使虱子能够附着在半水生水獭身上的特殊适应性。此外，还比较了来自不同地理区域的虱子与先前报告中的标本之间的形态。扩增了细胞色素氧化酶亚基I（COI）线粒体DNA的一个区域，首次对虱子进行分子特征分析，并检测德国水獭虱种群之间的遗传差异。据信，专性寄生虫甚至在其宿主种群数量下降之前就会减少。德国北部水獭种群的恢复可能是一种反向效应的例子，即宿主物种的回归导致专性寄生虫的回归，这反映了整体物种生物多样性的最终提升。
