Recent estimates of the size at first maturity (L) of showed contradictory results with a decreasing in the fish stock biomass encompassed by increasing values of L. The methodological approach used hereby allowed to separate sardines classified in the virginal maturity stage from those categorized in the recovery stage, and ready for one next spawning event. This study evaluated the hypothesis of the existence of separated stocks experiencing distinct environmental conditions and fishing pressures which may have altered L estimates using a robust dataset based on biological samples collected along the entire species distribution area in the southeast-south Brazilian coast [Rio de Janeiro (RJ), São Paulo (SP), Paraná (PR), Santa Catarina (SC) and Rio Grande do Sul (RS)] between 2000 and 2018. A reclassification of the gonadal maturity stages provided a more realistic estimate of L Combining biological, reproductive, fishing data and the mean temperature of the catch (MTC), the leave-one-out classification correctly re-assigned individuals with an overall accuracy of 85% [100% (RJ), 45% (SP), 99% (PR), 99% (SC) and 82% (RS)]. The connectivity between the local populations of off RJ (23°S) and the southern populations is limited, contrasting to spatial structured semi-discrete population-units found between SP and RS (24°S-30°S). The northern extreme population-unit (RJ, 22°S-23°S) showed an expressive reduction of L, and a negative correlation was detected between the increasing MTC values and the abundance of early maturing individuals and recruits of the species. Stock specific L estimates seemed to act as indicators of long term environmental fluctuations.

中文翻译：

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西南大西洋围网渔业中巴西沙丁鱼 Sardinella brasiliensis 繁殖的生物模式：长期评估

最近对第一次成熟大小 (L) 的估计显示出矛盾的结果，随着 L 值的增加，鱼群生物量减少。此处使用的方法允许将分类在处女成熟阶段的沙丁鱼与分类在成熟成熟阶段的沙丁鱼分开。恢复阶段，并为下一次产卵事件做好准备。本研究评估了存在不同环境条件和捕捞压力的分离种群的假设，这些条件和捕捞压力可能改变了 L 估计值，使用基于巴西东南-南海岸整个物种分布区收集的生物样本的可靠数据集[里约热内卢] (RJ)、圣保罗 (SP)、巴拉那 (PR)、圣卡塔琳娜州 (SC) 和南里奥格兰德州 (RS)] 2000 年至 2018 年间。对性腺成熟阶段的重新分类提供了对 L 的更现实的估计。 、繁殖、捕捞数据和捕获物的平均温度 (MTC)，留一法分类正确地重新分配了个体，总体准确率为 85% [100% (RJ)、45% (SP)、99% (PR)、99% (SC) 和 82% (RS)]。与 SP 和 RS (24°S-30°S) 之间发现的空间结构半离散人口单元相比，RJ (23°S) 附近的当地人口与南部人口之间的连通性有限。北部极端种群单位（RJ，22°S-23°S）表现出 L 的显着减少，并且在增加的 MTC 值与早熟个体和物种新成员的丰度之间检测到负相关。种群特定的 L 估计值似乎可以作为长期环境波动的指标。