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首页> 外文期刊>Aquatic Living Resources >Spawning time, age and size at maturity, and fecundity of sandeel,Ammodytes marinus, in the north-eastern North Sea and in unfished coastalwaters off Norway
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Spawning time, age and size at maturity, and fecundity of sandeel,Ammodytes marinus, in the north-eastern North Sea and in unfished coastalwaters off Norway

机译：北挪威东北部和挪威以外未捕鱼的沿海地区的沙e，沙门氏菌（Ammodytes marinus）的产卵时间，年龄和大小以及繁殖力

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摘要

We studied the reproductive biology of the lesser sandeel, Ammodytes marinus, on the fishing grounds of the east central North Sea and on an unfished ground off the coast of southwest Norway. As in other parts of the North Sea, gonad growth appeared to start in September and spawning occurred in December-January. Based on data from the spawning period, maturity ogives. by length and age were derived. The length and age at 50% maturity was 14 cm and 3.2 years respectively in both study areas. The age estimate is 1 year higher than that found previously in the southern North Sea and adopted for the ICES-assessments of the North Sea spawning stock. Estimates of fecundity appeared higher in the North Sea than in coastal waters, at least for large fish. The coastal water estimates also seemed low compared with fecundity at length relationships previously published from Shetland, Fair Isle, and Dogger bank. The sex ratio seldom deviated substantially from the 1: 1 ratio, but in summer there appeared to be a surplus of females. Due to spatial differences in age-structure, the proportion of adults was generally much lower on the fishing grounds of the North Sea proper than on the unfished coastal ground. In the middle of the spawning period, however, aggregations of adults occurred on the North Sea grounds.
机译：我们在北中东部东部的渔场和挪威西南沿海未捕鱼的陆上研究了小沙sand（Ammodytes marinus）的生殖生物学。与北海其他地区一样，生殖腺的生长似乎始于9月，产卵发生在12月至1月。根据产卵期的数据，成熟度良好。通过长度和年龄得出。两个研究区域的成熟度为50％时的长度和年龄分别为14厘米和3.2岁。年龄估计数比以前在北海南部发现的年龄高1年，并用于北海产卵种群的ICES评估。对北海的繁殖力估计似乎比沿海水域高，至少对于大鱼而言。与先前从设得兰群岛，费尔岛和多格河岸发表的长期繁殖力相比，沿海水域的估计值似乎也较低。性别比例很少有明显偏离1：1的比例，但是在夏季，女性似乎过剩。由于年龄结构的空间差异，在北海适当的渔场上，成年成年人的比例通常要比未捕鱼的沿海地段低得多。但是，在产卵期的中段，在北海地面上有成虫聚集。

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