Body size dimorphism of sea-reared Atlantic salmon (Salmo salar L.): Implications for the management of sexual maturation and harvest quality
Body size dimorphism of sea-reared Atlantic salmon (Salmo salar L.): Implications for the management of sexual maturation and harvest quality
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DOI：
10.1016/j.aquaculture.2010.01.029
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发表时间：
2010-03-23
期刊：
影响因子：
4.5
通讯作者：
Migaud, H.
中科院分区：
文献类型：
--
作者：
Leclercq, E.;Taylor, J. F.;Migaud, H.
未成熟和早期性招募队列的养殖苏格兰大西洋鲑鱼之间的身体大小的二型性进行了调查，以期优化在海上的第二年早期成熟的实际管理。混合性别的小鲑鱼从一个单一的菌株和淡水来源被放养到四个离散的商业网站，并在收获时取样，从2007年6月至12月，15至22个月后海上转移。个体进行性别鉴定，并根据性腺体细胞指数（GSI）和卵母细胞领先期确定其成熟状态。测定体重（BW）、叉长（FL）和富尔顿状态因子（K），分析肉质。未成熟雌雄混合群体和单独分析的各性别个体均表现出等长的体重-体长关系（WLR），但K值表现出季节性变化。未成熟的大西洋鲑鱼的身体大小一直是两性异形的，雄性表现出更高的BW（+13.4%）和FL（+5.9%），但比雌性低K（-5.0%）。在6月和7月，处于性成熟早期阶段的个体的BW（+35.2%）和K（+20.6%）显著高于未成熟队列。在此期间，BW，FL和K一起或BW单独在我们的离散站点中是早熟的强标准指标。在这项研究中描述的身体大小二态性表明，性别比是一个重要的参数养殖大西洋鲑鱼种群，这是可能会发生变化的重量分级和人口组成（性别比和成熟率）影响的季节性K通常在收获时观察到。重要的是，大西洋鲑鱼在春季成熟的承诺，可以快速，准确地估计在一些离散的人口，通过使用简单的重量长度的形态指标，其特征在于在一个单一的饲养单位。在成熟率估计之后，根据预测的股票形态结构实施的重量分级可以用于在其肉质保持最佳的阶段选择性地收获高比例的成熟个体。这可以作为一个强大的和实用的现场成熟管理工具，在鲑鱼产业以及其他商业上重要的鱼类物种。皇冠版权所有（C）2010由爱思唯尔B. V.出版保留所有权利。
Body size dimorphism between immature and early sexually recruited cohorts of farmed Scottish Atlantic salmon were investigated with the view to optimize the practical management of early maturation over the second-year at sea. Mixed-sex smolts from a single strain and freshwater source were stocked into four discrete commercial sites and sampled at harvest from June to December 2007, 15 to 22 months post-sea transfer. Individuals were sexed and their maturity status was determined based on gonado-somatic-index (GSI) and oocyte leading stage. Whole body weight (BW), fork length (FL) and Fulton condition factor (K) were measured and flesh quality analyzed. The immature mixed-sex population and each gender analyzed separately had an isometric weight-length relationship (WLR) but exhibited seasonal variations in K. Body size of immature Atlantic salmon were consistently sexually dimorphic with males exhibiting a higher BW (+ 13.4%) and FL (+5.9%) but a lower K (-5.0%) than females. Individuals at an early stage of sexual maturation had a significantly higher BW (+35.2%) and K (+20.6%) than the immature cohort in June and July. During this period BW, FL and K together or BW alone was strong and standard indicators of early maturity in our discrete sites. Body size dimorphism described in this study shows that sex-ratio is an important parameter of farmed Atlantic salmon populations which is likely to vary following weight-grading and that population composition (sex-ratio and maturation rate) affects the seasonality in K typically observed at harvest. Importantly, the commitment of Atlantic salmon into maturation in spring can be rapidly and accurately estimated in a number of discrete populations by using simple weight-length morphological indicators characterized in a single rearing unit. Following maturation rate estimation, weight-grading implemented according to the predicted stock morphological structure could be used to selectively harvest a high proportion of maturing individuals at a stage where their flesh quality remains optimal. This could be applied as a powerful and practical on-site maturation management tool in the salmon industry as well as in other commercially important fish species. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.