The annual reproductive cycle of the female lesser spotted dogfish, Scyliorhinus canicula L., and its endocrine control
The annual reproductive cycle of the female lesser spotted dogfish, Scyliorhinus canicula L., and its endocrine control
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雌性小斑角鲨Scylorhinus canicula L.的年繁殖周期及其内分泌控制
DOI：
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发表时间：
1979
期刊：
影响因子：
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通讯作者：
J. M. Dodd
中科院分区：
文献类型：
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作者：
J. Sumpter;J. M. Dodd
雌性小斑角鲨（Scyliorhinus canicula L.）生殖生理的各个方面都表现出明显的年周期。垂体腹侧叶促性腺激素含量、血浆雌二醇和睾酮水平在整个秋季随着卵巢的复发和在输卵管中产卵的鱼的百分比的增加而上升。垂体促性腺激素和血浆性类固醇水平在整个冬季保持升高，但在春季下降，两个月后，促性腺指数（GSI）和卵在输卵管中的鱼的百分比都下降。促性腺激素和性类固醇水平在初夏最低，再次早于最低GSI和产卵率两到三个月。其中一些周期是明显的，垂体促性腺激素水平全年变化超过100倍，雌二醇水平变化超过10倍。结果表明，雌角鲨的产卵高峰出现在冬春两季，但繁殖期较长。
Various aspects of the reproductive physiology of the female lesser spotted dogfish, Scyliorhinus canicula L., demonstrate marked annual cycles. Pituitary ventral lobe gonadotrophin content and plasma oestradiol and testosterone levels rise through the autumn as the ovary recrudesces and the percentage of fish bearing eggs in the oviducts increases. The pituitary gonadotrophin and plasma sex steroid levels remain elevated throughout the winter but decrease during the spring, two months prior to a fall in both the gonadosomatic index (GSI) and the percentage of fish with eggs in their oviducts. The lowest gonadotrophin and sex steroid levels are found in early summer, again preceding the minimum GSI and rate of egg-laying by two or three months. Some of these cycles are pronounced, the pituitary gonadotrophin levels varying by more than 100-fold, and the oestradiol levels by more than 10-fold, throughout the year. It is concluded that the female dogfish has a very extended breeding season, though the peak frequency of egg-laying occurs in the winter and spring.