已收录 273156 条政策
 政策提纲
  • 暂无提纲
Size, age and spawning frequency of landlocked Arctic charr Salvelinus alpinus (L.) in Svartvatnet, Svalbard
[摘要] This contribution reports the analysis of a sample of landlocked Arctic charr collected with gillnets in Svartvatnet, Svalbard, 1964. This is the first scientific sample from a landlocked charr population from Svalbard. We found a very prominent modal group of large, old and sexually adult fish of both sexes. Their length ranged from 15 to 62 cm, but 92% of the fish were longer than 40 cm and 62% of them fell in the 45 to 54 cm interval. The age range was 7 to 31 years, but 93% were 14 years or older and represented 18 year-classes. The length-at-age of the charr seemed to increase steadily until they reached the size and age of the modal group. The growth rate decreased sharply after that. The mortality rates within the age span of the modal group seemed to be low. The ages at first spawning for most of the charr in the sample were between 7 and 9 years and spawning cycles of two years were indicated.
[发布日期]  [发布机构] 
[效力级别]  [学科分类] 自然科学(综合)
[关键词]  [时效性] 
   浏览次数:5      统一登录查看全文      激活码登录查看全文