Relationship between Marteilioides chungmuensis infection and reproduction in the Pacific oyster, Crassostrea gigas.
Relationship between Marteilioides chungmuensis infection and reproduction in the Pacific oyster, Crassostrea gigas.
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DOI：
10.1016/j.jip.2007.06.001
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发表时间：
2007-11
影响因子：
3.4
通讯作者：
K. L. Tun;N. Itoh;N. Ueki;T. Yoshinaga;K. Ogawa
中科院分区：
文献类型：
--
作者：
K. L. Tun;N. Itoh;N. Ueki;T. Yoshinaga;K. Ogawa
一种原生动物副粘虫寄生虫，感染太平洋牡蛎卵母细胞。研究了感染对中华绒螯蟹生殖周期的影响。在日本冈山县连续两年调查了吉加斯。在雄性牡蛎，性腺发育开始于2月/3月，成熟是在6月和产卵活动延长从7月至9月。在11月和12月，没有看到雄性牡蛎，可能是因为它们的性腺退化为结缔组织，它们变成了未分化的牡蛎。与此相反，雌牡蛎，其中寄生虫孢子的形成发生，仍然携带卵母细胞，直到第二年3月和产卵过程的雌牡蛎需要5个月的时间比男性在流行区。M.从7月到9月，大多数雌牡蛎处于产卵期，感染率上升，从10月到次年4月，牡蛎处于枯竭期，感染率下降。第二年5月，感染率再次上升，第二年7月出现高感染率。当患病率比较不同年龄组的牡蛎，较高的患病率被检测到比年轻的牡蛎。组织学检查表明，10月至次年3月，感染牡蛎持续产生卵母细胞并反复产卵，在此期间，健康牡蛎的生殖活动不活跃。寄生虫可在较长的产卵期内感染受感染牡蛎的卵母细胞。这些结果表明M.中牟牡蛎为了自己的繁殖利益，延长了受感染牡蛎的繁殖期。
Marteilioides chungmuensis, a protozoan paramyxean parasite, infects the oocytes of the Pacific oyster, Crassostrea gigas. The effects of infection on the reproductive cycle of C. gigas were investigated over two consecutive years at Okayama Prefecture, Japan. In male oysters, gonadal development began during February/March, maturity was achieved in June and spawning activity extended from July to September. In November and December, male oysters were not seen, probably because their gonads regressed to connective tissue and they transformed into undifferentiated oysters. By contrast, female oysters, in which parasite spore formation occurred, were still carrying oocytes until the following March and the spawning process of female oysters took 5 months longer than that of males in epizootic areas. The prevalence of M. chungmuensis infection increased from July to September, when most female oysters had their spawning period, and declined from October to the following April when oysters were at the spent stage. The prevalence of infection increased again in May of the following year and high prevalence was observed in the following July. When prevalence was compared between oysters of different age classes, higher prevalence was detected in older than in younger oysters. Histological examination showed that infected oysters produced oocytes continuously and spawned repeatedly from October to March, during which period healthy oysters were reproductively inactive. Parasites can infect the oocytes of infected oysters throughout the longer spawning period. These observations suggest that M. chungmuensis extends the reproductive period of infected oysters for its own reproductive benefit.