摘要
对科威特湾微茎科滨鹬马蹄吸虫幼虫期的中间宿主双带盾桑椹螺(Clypeomorus bifasciata)及小相手蟹(Nanosesarma minutum)的季节动态进行了研究。调查期超过一年,在检查的1 600只螺和415只蟹中, 11.8 %的螺感染了8种马蹄属线虫中的一种,且以滨鹬马蹄吸虫的感染占优势(9.9 %螺感染) ; 80 %的蟹感染滨鹬马蹄吸虫囊蚴。虽然一年四季两种宿主都会感染,但吸虫的流行和尾蚴(指成熟期感染)在夏季呈现高蜂。从螺体排出的尾蚴具有明显季节性,在此海湾必须要超过最低温度20℃。总的感染率在较大(较老)的螺里有所下降,显示吸虫影响宿主生存并随之影响宿主群体结构。囊蚴的感染丰度与蟹的个体大小有明显相关性;较大的蟹感染较多的囊蚴,显示宿主能耐受更多的吸虫。调查显示,囊蚴的感染率与蟹的大小或性别无相关性。囊蚴体外脱囊以及产卵吸虫的释放证明,成熟虫体终年存在于所有大小和性别不同的蟹里,显示从蟹到鸟的持续感染是可能的。总的来说,滨鹬马蹄吸虫在海湾的传播动态是由这两种无脊椎动物宿主来协调,并似乎是被一系列依赖于温度的活动控制,这些活动影响易感宿主种群及感染性幼虫期尾蚴和囊蚴的存在。
The seasonal dynamics of larval stages of the microphallid trematode Maritrema eroliae Yamaguti, 1939 in intermediate hosts, the prosobranch snail Clypeomorus bifasciata（Sowerby, 1855）and the brachyuran crab Nanosesarma minutum（de Man, 1887）, in Kuwait Bay was examined. Over a one-year period,1 600 snails and 415 crabs were collected and examined for larval trematodes, 11.8% of snails were infected with one of 8 species dominated by M.eroliae（9.9%）, and 80% of crabs harbored M.eroliae metacercariae. Although infections persisted in both host species throughout the year, significant summer peaks were recorded in parasite prevalence and cercarial emergence（i.e., indicating mature infection）in snails. Cercarial emergence from snails was significantly seasonal, a minimum temperature of 20℃ in the Bay must be exceeded to activate emergence. Overall prevalence of infections decreased in larger（older）snails, suggesting parasite interference with host survival and consequently with host population structure. There was a significant correlation between metacercarial abundance and crab size; larger crabs harbored more metacercariae suggesting host tolerance to parasite accumulation. No correlations were detected between metacercarial prevalence and crab size or sex. The presence of mature parasites throughout the year in crabs of both sexes and all size classes, demonstrated by in vitro metacercarial excystment and liberation of ovigerous flukes, suggests continuous transmission from crab to bird is possible. In general, the transmission dynamics of M.eroliae in the Bay are coordinated between the two invertebrate host species and appears to be controlled by a set of temperature-dependent activities influencing the availability of susceptible host populations and infective larval stages, cercariae and metacercariae[Acta Zoologica Sinica 53（3）：463-469,2007].
出处
《动物学报》
SCIE
CAS
CSCD
北大核心
2007年第3期463-469,共7页
ACTA ZOOLOGICA SINICA
基金
This research was partiallyfunded by Graduate Student Grant fromthe College of Graduate Studies , Kuwait University.
关键词
滨鹬马蹄吸虫
双带盾桑椹螺
小相手蟹
科威特
尾蚴
囊蚴
种群动态
Microphallid trematode, Maritrema eroliae, Clypeomorus bifasciata, Nanosesarma minutum, Kuwait, cercaria, metacercaria, population dynamics
