We investigated the population structure, sex ratio, growth parameters, longevity and natural mortality (M) of a hololimnetic population of the Amazon River prawn Macrobrachium amazonicum that presents different morphotypes. Sampling was performed monthly from May 2017 to April 2018 in a water reservoir in the municipality of Severínia, São Paulo, southeast Brazil. Juveniles, ovigerous females (OF) and males (except the morphotypes GC2) were more abundant in the dry season. The overall and seasonal sex ratio leaned toward males. Males were also more abundant in the larger size classes. Growth parameters for males and females were CL∞ = 19.98 mm and 16.94 mm, k = 4.42 year⁻¹ and 3.94 year⁻¹, t₀ = -0.3762 and 0.0628, respectively. Longevity was 1.04 years for males and 1.17 years for females, and M was 4.43 year⁻¹ for males and 3.94 year⁻¹ for females. The OF sampled presented smaller sizes in comparison to those registered in the literature, which may be because they reach sexual maturity sooner than in other localities. Males attained larger asymptotic sizes than females; however, their increased growth rate resulted in lower longevity and higher M. High M values among larger males can occur due to disputes over territory, food, and females, while smaller males are often cannibalized. Both sexes presented low longevity, intense growth rates and small asymptotic sizes in comparison to those registered in the literature, which is likely due to high instability in the system caused by environmental variations and anthropic influences.

我们调查了呈现不同形态类型的亚马逊河对虾Macrobrachium amazonicum全息种群的种群结构、性别比例、生长参数、寿命和自然死亡率 (M) 。从 2017 年 5 月至 2018 年 4 月，每月在巴西东南部圣保罗市塞韦里尼亚市的一个水库中进行采样。幼鱼、卵生雌性（OF）和雄性（除了形态型 GC2）在旱季更为丰富。总体和季节性性别比例倾向于男性。在较大的尺寸等级中，雄性也更丰富。雄性和雌性的生长参数为 CL∞ = 19.98 mm 和 16.94 mm，k = 4.42 年^-1和 3.94 年^-1，t ₀ = -0.3762 和 0.0628，分别。男性的寿命为 1.04 年，女性为 1.17 年，M为男性4.43 年^{-1 年}，3.94 年^{-1 年}对于女性。与文献中登记的相比，所采样的 OF 呈现出较小的尺寸，这可能是因为它们比其他地方更快地达到性成熟。男性比女性获得更大的渐近尺寸；然而，它们的增长速度增加导致寿命较短和 M 较高。 由于领土、食物和雌性的争议，较大雄性的高 M 值可能发生，而较小的雄性往往被蚕食。与文献中记录的相比，两性都呈现出低寿命、高增长率和小渐近尺寸，这可能是由于环境变化和人为影响引起的系统高度不稳定性。