This study aimed to compare the spatio‐temporal distribution of demographic groups of Hepatus pudibundus in the Ubatuba Bay, São Paulo, Brazil, over a 20‐year interval. Two 1‐year samplings were conducted: the 1st period (P1) ran from September 1995 to August 1996 and the 2nd period (P2) ran from September 2016 to August 2017. Samples were taken from five stations that differed in depth (5, 10, and 15 m) and location (exposed area and sheltered area), aboard a shrimp fishing boat. Over the 20‐year period, the percentage of fine sediment increased in all stations. In total, we captured 865 H. pudibundus individuals in the P1 and 4,222 in the P2. The higher abundance seen in the P2 may have been caused by the effects of an intense ENSO event in Ubatuba, as well as co‐occurring protective actions against fisheries activities in the region. The spatial distribution also changed after 20 years: In the P1, H. pudibundus were more concentrated in the 15 m station and exposed area, but they shifted to the sheltered area in the P2. This change may be related to the increase of fine sediments in this area, and to the fact that it is naturally protected from fisheries. According to the correspondence analysis, the abundance of males and juveniles was correlated with spring and winter, respectively. In the P1, females were more abundant in spring, whereas in the P2 they were more abundant in summer, which may be explained by a higher nutrient availability to the larvae in the summer of the P2. Our comparisons over the 20‐year interval revealed that the spatio‐temporal distribution of H. pudibundus has changed and that the population is well established in Ubatuba Bay.

中文翻译：

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在厄尔尼诺现象（ENSO）的影响下，评估区域中20年间隔内河豚肝（Decapoda，Brachyura）的时空分布变化的因素

这项研究旨在比较20年间巴西圣保罗乌巴图巴湾（Ubatuba Bay）的Hepatus pudibundus人口群体的时空分布。进行了两次为期1年的采样：第一阶段（P1）于1995年9月至1996年8月，第二阶段（P2）于2016年9月至2017年8月。样本取自五个深度不同的气象站（5，10 ，以及15 m）和位置（暴露区域和庇护区域），在虾船上。在20年期间，所有站点的细泥沙百分比均增加。总共我们捕获了865 H. pudibundusP1中的个人和P2中的4,222。在P2中看到的较高的丰度可能是由于乌巴图巴（Ebatuba）发生的一次强烈ENSO事件以及对该地区渔业活动同时采取的保护行动所造成的。20年后，空间分布也发生了变化：在P1中，p。pudibundus它们更多地集中在15 m车站和裸露区域，但它们转移到了P2的庇护区域。这种变化可能与该地区细颗粒沉积物的增加有关，也与它自然受到渔业保护的事实有关。根据对应分析，男性和青少年的丰度分别与春季和冬季相关。在P1中，雌性在春季更为丰富，而在P2中，它们在夏季更为丰富，这可能是由于P2夏季幼虫的养分利用率更高。我们在20年的时间间隔内进行的比较显示，H。pudibundus的时空分布发生了变化，并且在乌巴图巴湾（Ubatuba Bay）的种群已经建立。