This study examines the variations in relative abundance, test size, and biomass of the species (Foraminifera) over the last 112 ka BP on the northern slope of the Pelotas Basin, Southern Brazil. The analyses were based on 651 individuals from 42 samples distributed along the cores SIS-249 (Marine Isotope Stage 5 to 3) and SIS-188 (Marine Isotope Stage 3 to 1). was the most abundant species of the Bolivinitidae family in these cores, particularly during warmer periods (MIS 1 and 5). Nine other species of this family were identified: sp., sp., and Larger test lengths were observed during MIS 3 in the both cores. The summed biomass was higher during MIS 5 in the SIS-249 core and lower during MIS 3 in the SIS-188 core. The fluctuations observed in the relative abundance and summed biomass of are consistent with the oscillations in total organic carbon flow, and the variations in primary productivity between the interglacial and glacial periods. The results suggest that this infaunal species is favored by the regular supply of refractory organic matter during warmer periods but faces increased competition from shallow infaunal and epifaunal species during glacial periods, when the flow of labile organic matter increases.

中文翻译：

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佩洛塔斯盆地北部陆坡晚第四纪玻利维亚普通虫的相对丰度和生物测量

本研究调查了巴西南部佩洛塔斯盆地北坡过去 112 ka BP 中该物种（有孔虫）的相对丰度、测试大小和生物量的变化。分析基于沿核心 SIS-249（海洋同位素阶段 5 至 3）和 SIS-188（海洋同位素阶段 3 至 1）分布的 42 个样本中的 651 个人。是这些核心中最丰富的 Bolivinitidae 物种，特别是在温暖时期（MIS 1 和 5）。该科的其他 9 个物种已被鉴定：在 MIS 3 期间，在两个核心中观察到 sp.、sp. 和更大的测试长度。 SIS-249 核心的 MIS 5 期间的总生物量较高，而 SIS-188 核心的 MIS 3 期间的总生物量较低。观察到的相对丰度和总生物量的波动与总有机碳流量的波动以及间冰期和冰河期之间初级生产力的变化一致。结果表明，这种动物物种在温暖时期受到难降解有机物定期供应的青睐，但在冰期期间，当不稳定有机物流量增加时，面临来自浅层动物和表层动物物种的竞争加剧。