Mitrani Department of Desert Ecology, Institute for Dryland Environmental Research, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, 84990 Midreshet Ben-Gurion, Israel.
Parasitology. 2011 Aug;138(9):1154-63. doi: 10.1017/S0031182011000758. Epub 2011 Jul 18.
We asked whether the age of a rodent host affects the feeding performance of fleas. We predicted that fleas would perform better on young and old than on adult rodents. To test this prediction, we determined bloodmeal size, rate of digestion and time of survival after a single bloodmeal in Xenopsylla ramesis feeding on Meriones crassus of different ages. Fleas took less blood from subadult and adult than from juvenile and old animals. Fleas digested blood of old hosts at the highest rate and blood of juvenile hosts most slowly. After a bloodmeal, fleas survived the longest if fed on a juvenile host. The effect of host gender on bloodmeal size and survival after a bloodmeal was manifested only in (a) subadult and adult hosts and (b) subadult hosts, respectively. Host gender affected the rate of digestion differently among digestion stages and host age cohorts. We explain the observed patterns in flea performance in terms of changes in the host's immune defences and nutritional quality of blood during the host's individual life. Our observations suggested that a host of a particular age could not be unequivocally predicted to be more or less beneficial for a parasite than a younger or an older host.
我们探讨了宿主啮齿动物的年龄是否会影响跳蚤的取食表现。我们预测，跳蚤在幼龄和老龄宿主上的表现会优于成年宿主。为了验证这一假设，我们测定了感染不同年龄麦氏血蜱的赤颈袋鼠血食大小、消化率和单次取食后的存活时间。与幼年和老龄宿主相比，亚成体和成年宿主上的跳蚤取食量较少。老龄宿主的血液消化速度最快，而幼年宿主的血液消化速度最慢。取食后，若以幼年宿主为食，跳蚤的存活时间最长。宿主性别对取食量和取食后存活时间的影响仅在（a）亚成体和成年宿主以及（b）亚成体宿主中表现出来。宿主性别在不同消化阶段和宿主年龄组之间对消化速度的影响不同。我们根据宿主个体生命过程中免疫防御和血液营养质量的变化来解释跳蚤表现出的这些模式。我们的观察结果表明，特定年龄的宿主并不能被明确地预测为比年轻或年老宿主对寄生虫更有利或更不利。
