Age and growth rate of juvenile bluefin tuna Thunnus thynnus from the Mediterranean sea (Sicily, Italy)
Age and growth rate of juvenile bluefin tuna Thunnus thynnus from the Mediterranean sea (Sicily, Italy)
复制标题
地中海（意大利西西里岛）蓝鳍金枪鱼幼鱼 Thunnus thynnus 的年龄和生长速度
DOI：
10.3989/scimar.2005.69n2241
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发表时间：
2005
期刊：
影响因子：
1.4
通讯作者：
F. Andaloro
中科院分区：
文献类型：
--
作者：
M. Mesa;M. Sinopoli;F. Andaloro
对大西洋蓝鳍金枪鱼（Thunnus thynnus）幼鱼矢状耳石的微观结构分析，可以用来估计地中海出生的年轻个体的年龄和生长速度。本署于2002年8月底至11月初在西西里岛北部海岸收集蓝鳍金枪鱼幼鱼样本，这些幼鱼是当地小规模远洋渔业捕捞大西洋鲣鱼和海豚的副渔获物。对56个样本进行了耳石年龄读数，样本长度在195至400毫米之间，总重量在112至1266克之间。根据从耳石核心到反喙部的计数路径进行微增量分析，幼鱼的年龄在77 ~ 153天之间。在整个尺寸范围内，估计的生长速率几乎是线性的，约为2.0-2.37 mm/天。根据体长-体重关系和估计体长-年龄数据，2月龄、3月龄和4月龄幼鱼的平均体长-年龄分别为168、429和813 g。此外，通过老化数据反算得到的蓝鳍金枪鱼的孵化日期分布表明，产卵期至少为2个月，即5月中旬至7月中旬，6月中旬为产卵高峰期。我们的数据表明，幼蓝鳍金枪鱼在其生命的最初阶段具有非常高的生长速度，在四个月内达到1公斤以上的体重。
The microstructural analysis of the sagittal otoliths of juvenile Atlantic bluefin tuna, Thunnus thynnus , can be used to estimate the age and growth rate of young-of-the-year individuals born in the Mediterranean. Samples of juvenile bluefin tuna, obtained as by-catch of the local small-scale pelagic fishery for Atlantic bonito and dolphinfish, were collected off the northern coast of Sicily between late August and early November 2002. Otolith age readings were carried out on 56 specimens ranging between 195 and 400 mm fork length and between 112 and 1266 g total weight. Based on microincrement analysis along a counting path from the otolith core to the antirostrum, juvenile fishes were found to be between 77 days and 153 days old. The estimated growth rate was practically linear over the whole size range, accounting for about 2.0-2.37 mm/day. Derived from the length-weight relationship and the estimated length-at-age data, the mean weight-at-age was 168, 429 and 813 g for 2, 3 and 4 month-old juveniles respectively. Furthermore, the hatching date distribution of bluefin tuna, obtained by means of the back-calculation of ageing data, indicated a spawning period of at least two months, namely from mid-May to mid-July, with a peak in mid-June. Our data indicate that juvenile bluefin tuna have a very high growth rate in the first part of their life, reaching a weight of more than 1 kg in four months.