Benthos of the Cariaco Basin: Is the Eukaryotic Community Similar to that of the Santa Barbara Basin?

Cariaco盆地的底栖生物：真核生物群落与圣巴巴拉盆地的底栖生物相似吗？Cariaco盆地是地球上已知的第二大缺氧水体，因其水柱过程和沉积记录而受到广泛研究，但对该盆地缺氧和缺氧区的底栖生物几乎一无所知。在圣巴巴拉盆地的沉积缺氧-缺氧界面上描述了丰富的后生动物和原生动物群落，这项研究将探讨卡里亚科盆地支持类似丰富的海底联合体的可能性。拟议项目的总体目标是描述加勒比盆地的真核底栖生物。我们将：1)使用Percoll梯度提取和荧光染色对真核生物群落进行量化；2)使用DAPI染色和超微结构检查真核生物的关联性；3)使用各种活性指示器(即荧光探针、超微结构、传统的玫瑰色孟加拉染色)鉴定底栖有孔虫组合；以及4)确定跨越缺氧/缺氧界面的底栖有孔虫群落组成的变化。这些具体目标将利用在一次短途巡航中收集的材料，于2001年5月使用委内瑞拉RV Hermano Gines号轮船对Cariaco盆地进行采样。将在东北部的8个地点中的每一个地点，在东部次盆地的一个地点，以及在两个次盆地之间的鞍座上的一个地点进行复制多核。底层水中的氧浓度将用微温克勒分析进行测定。研究结果将对底栖生态、生物多样性和生物地理学以及古海洋学领域产生影响。如果确定新的共生或适应这种极端环境，细胞生物学和进化生物学也可能受益。

Benthos of the Cariaco Basin:Is the Eukaryotic Community Similar to that of the Santa Barbara Basin?The Cariaco Basin, the second largest known anoxic body of water known on Earth, has been extensively studied for its water-column processes and sedimentary record, but virtually nothing is known about the benthos of the oxygen-depleted and anoxic regions of the basin. An abundant community of metazoans and protists has been described from the sedimentary anoxic-oxic interface in the Santa Barbara Basin, and this study will examine the possibility that the Cariaco Basin supports a similarly rich benthic consortium. The broad objective of the proposed project is to describe the eukaryotic benthos of the Cariaco Basin. We will: 1) quantify the eukaryotic community using Percoll gradient extraction and fluorogenic staining; 2) examine the eukaryotes for prokaryotic associates using DAPI staining and ultrastructural examination; 3) identify the benthic foraminiferal assemblage using various viability indicators (i.e., fluorogenic probes, ultrastructure, conventional rose Bengal staining); and 4) determine changes in the benthic foraminiferal community composition across the anoxic / oxic interface. These specific aims will be addressed using material collected on one short cruise to sample the Cariaco Basin using the Venezuelan ship RV Hermano Gines in May 2001. Replicate multicores will be taken at each of 8 sites in the northeastern sector, at one site located in the eastern sub-basin, and at one site on the saddle between the two sub-basins. Bottom-water oxygen concentrations will be determined with microwinkler analysis. Results will impact the areas of benthic ecology, biodiversity and biogeography, and paleoceanography. Cell biology and evolutionary biology may also benefit if novel symbioses or adaptations to this extreme environment are identified.