Effective fisheries management requires fish size, growth and mortality information representative of the population and location of interest. Golden perch Macquaria ambigua is long lived, potamodromous and widespread in the Murray–Darling Basin (MDB), Australia. Using a sample spanning 13 river systems and 10° of latitude, we examined whether the maximum size of golden perch differed by latitude and whether growth and mortality varied between northern and southern MDB regions. The length, weight and age ranges of golden perch sampled (n=873) were 52–559mm, 2–3201g and 0+ to 26+ years respectively, and maximum length and weight were unaffected by latitude. Length and age–length distributions represented by age–length keys varied by region, with greater variability in age-at-length and a larger proportion of smaller individuals in northern MDB rivers, which generally exhibit greater variability in discharge. Growth and mortality rates were similar between regions, and an MDB-wide von Bertalanffy growth model (L∞=447, k=0.32 and t0=–0.51) and instantaneous mortality rate (Z=0.20) best described the data. An MDB-wide length–weight equation also provided the best fit (W=6.76×10–6 L3.12). Our data suggest that the MDB can be treated as one management unit in terms of golden perch maximum size, growth and mortality parameters.

中文翻译：

---

跨纬度梯度的河流金鲈（Macquaria ambigua）的大小、生长和死亡率

有效的渔业管理需要代表感兴趣的种群和位置的鱼类大小、生长和死亡率信息。金鲈 Macquaria ambigua 在澳大利亚的墨累-达令盆地 (MDB) 中寿命长，分布广泛。使用跨越 13 个河流系统和 10° 纬度的样本，我们检查了金鲈的最大尺寸是否因纬度而异，以及北部和南部 MDB 区域的生长和死亡率是否不同。采样的金鲈（n=873）的长度、重量和年龄范围分别为52-559mm、2-3201g和0+至26+岁，最大长度和重量不受纬度的影响。年龄-长度键代表的长度和年龄-长度分布因地区而异，MDB 河流中的体长年龄变异性更大，体型较小的个体比例更大，通常在流量方面表现出更大的变异性。不同地区的生长率和死亡率相似，MDB 范围的 von Bertalanffy 生长模型（L∞=447，k=0.32 和 t0=–0.51）和瞬时死亡率 (Z=0.20) 最能描述数据。MDB 范围的长度-重量方程也提供了最佳拟合（W=6.76×10-6 L3.12）。我们的数据表明，就金鲈最大尺寸、生长和死亡率参数而言，MDB 可以被视为一个管理单位。MDB 范围的长度-重量方程也提供了最佳拟合（W=6.76×10-6 L3.12）。我们的数据表明，就金鲈最大尺寸、生长和死亡率参数而言，MDB 可以被视为一个管理单位。MDB 范围的长度-重量方程也提供了最佳拟合（W=6.76×10-6 L3.12）。我们的数据表明，就金鲈最大尺寸、生长和死亡率参数而言，MDB 可以被视为一个管理单位。