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Abstract：
The length-weight relationship (LWR) and relative condition factor are widely used as the most important biological parameters to infer the growth pattern and well-being of fishes. The aim of our study was to investigate the growth parameters of the LWR in different growth phases of Hilsa (Tenualosa ilisha), a flagship species of Bangladesh, and compare its relative condition factors across its major habitats. Fish from various rivers in Bangladesh and the Bay of Bengal were sampled, their length-weight growth parameters were measured and subjected to statistical analysis with pooled data from other studies. An isometric growth pattern in Hilsa was predominantly found in the size classes of 25 ≤ TL (total length) < 30, 30 ≤ TL < 35, and TL ≥ 40. However, the size class TL < 25 showed negative allometric growth with the value of the exponent (b, also known as growth coefficient) between 2.797 and 2.833. The highest weight-growth of Hilsa was within the size class of 35 ≤ TL < 40, with exponent values of 3.271-3.381 (positive allometric growth) across habitats. Our results revealed that the exponent value varied significantly (P < 0.05) between different size classes of Hilsa except between 30 ≤ TL < 35 and TL ≥ 40; however, no such significant differences in the exponent values were found across habitats. The Akaike Information Criterion value was lowest for the size-specific length-weight regression model of Hilsa, indicating it was the best-fit model compared to the habitat-specific and pooled sample models. The relative condition factor of Hilsa by habitat was found in the order of Meghna > Bay of Bengal > Andharmanik > Biskhali > Tetulia > Padma. Additionally, the relative physiological well-being of Hilsa from the river Padma and Tetulia was poor compared to that of other habitats. A more in-depth analysis is required to determine the factors that can influence Hilsa\'s growth and well-being in relation to habitat quality. The present findings have significant relevance for fisheries biologists and managers in understanding and interpreting Hilsa\'s ecology, relative well-being of populations of same or contrasting habitats, demographic assessment, and for better management of Hilsa in the future.
摘要：
长度-重量关系（LWR）和相对条件因子被广泛用作推断鱼类生长方式和健康状况的最重要的生物学参数。我们研究的目的是研究Hilsa（Tenualosailisha）不同生长阶段LWR的生长参数，孟加拉国的旗舰物种，并比较其主要栖息地的相对条件因素。对孟加拉国和孟加拉湾各条河流的鱼类进行了采样，我们测量了他们的身长-体重生长参数,并使用其他研究的汇总数据进行统计分析.希尔萨的等距生长模式主要存在于25≤TL（总长度）<30、30≤TL<35和TL≥40的大小类别中。然而,大小等级TL<25显示出负的异速生长与指数的值(B，也称为增长系数）在2.797和2.833之间。Hilsa的最高体重增长在35≤TL<40的大小范围内，整个栖息地的指数值为3.271-3.381（正异速增长）。我们的结果表明，除了30≤TL<35和TL≥40之间，不同大小类别的Hilsa指数值之间存在显着差异（P<0.05）；但是，在不同的生境中没有发现如此显著的指数值差异。对于Hilsa的特定尺寸长度-权重回归模型，Akaike信息准则值最低，表明与特定栖息地和合并样本模型相比，它是最适合的模型。根据栖息地发现的Hilsa的相对条件因子顺序为Meghna>孟加拉湾>Andharmanik>Biskhali>Tetulia>Padma。此外,与其他栖息地相比，来自Padma和Tetulia河的Hilsa的相对生理健康状况较差。需要进行更深入的分析，以确定与栖息地质量相关的可能影响希尔萨生长和福祉的因素。本研究结果对渔业生物学家和管理者在理解和解释希尔萨的生态学方面具有重要意义。相同或不同栖息地的种群的相对福祉，人口评估，并在未来更好地管理希尔莎。
