Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, 25761 Büsum, Germany.
Department of Biological Sciences, University of Alberta, Edmonton T6G 0H6, Canada.
J Helminthol. 2020 Dec 9;94:e211. doi: 10.1017/S0022149X20000747.
Acanthocephalans are common intestinal parasites of marine mammals, the most widespread of which is the genus Corynosoma. In this study, parasite infrapopulations of two closely related species of Corynosoma were examined: Corynosoma enhydri from sea otters (Enhydra lutris) in Alaska (n = 12) and California (n = 19), and Corynosoma strumosum from seals in Germany (n = 22). Prevalence of C. enhydri was 100% in Californian otters, with a mean abundance of 30, and 83% in Alaskan otters, with a mean abundance of 232. In seals, C. strumosum had a prevalence of 65%, with a mean abundance of 33. Female C. enhydri dominated both Californian (82%) and Alaskan (79%) infections, while, in seals, female C. strumosum made up 68% of the parasite population. Reproduction rates for C. enhydri, with 16% (California) and 18% (Alaska) of females mated, were low compared to C. strumosum in seals, of which 40% of females were mated. Habitat selection also differed significantly between the two species. Corynosoma enhydri was found most frequently in the second and third fifths of the small intestine, while C. strumosum was found most frequently in the fourth. The differences in habitat selection and prevalence analysed in this study may be related to a trade-off between growth and reproduction between the two species.
棘头虫是海洋哺乳动物常见的肠道寄生虫,其中分布最广的属是棘头虫属。在这项研究中,检查了两种密切相关的棘头虫属寄生虫的寄生虫亚群:来自阿拉斯加(n = 12)和加利福尼亚(n = 19)海獭(Enhydra lutris)的棘头虫 enhydri,以及来自德国海豹的棘头虫 strumosum。加利福尼亚海獭中棘头虫 enhydri 的患病率为 100%,平均丰度为 30,阿拉斯加海獭中的患病率为 83%,平均丰度为 232。在海豹中,棘头虫 strumosum 的患病率为 65%,平均丰度为 33。雌性棘头虫 enhydri 主导了加利福尼亚(82%)和阿拉斯加(79%)的感染,而在海豹中,雌性棘头虫 strumosum 占寄生虫种群的 68%。棘头虫 enhydri 的繁殖率较低,加利福尼亚(16%)和阿拉斯加(18%)的雌性有 16%的雌性交配,而海豹中的棘头虫 strumosum 的繁殖率为 40%,雌性有 40%的雌性交配。两种物种之间的栖息地选择也有显著差异。棘头虫 enhydri 最常出现在小肠的第二和第三五分位,而棘头虫 strumosum 最常出现在第四分位。本研究分析的栖息地选择和患病率的差异可能与两种物种之间生长和繁殖之间的权衡有关。