This study provides an analysis of vesicomyid bivalve-symbiont community distribution across cold seep and hydrothermal vent areas in the Guaymas Basin (Gulf of California, Mexico). Using a combination of morphological and molecular approaches including fluorescent in situ hybridization (FISH), and electronic microscopy observations, vesicomyid clam species and their associated symbionts were characterized and results were analyzed in light of geochemical conditions and other on-site observations. A greater diversity of vesicomyids was found at cold seep areas, where three different species were present (Phreagena soyoae [syn. kilmeri], Archivesica gigas, and Calyptogena pacifica). In contrast, A. gigas was the only species sampled across the hydrothermal vent area. The same haplotype of A. gigas was found in both hydrothermal vent and cold seep areas, highlighting possible contemporary exchanges among neighboring vents and seeps. In either ecosystem, molecular characterization of the symbionts confirmed the specificity between symbionts and hosts and supported the hypothesis of a predominantly vertical transmission. In addition, patterns of clams could reflect potential niche preferences for each species. The occurrence of numerous traces of vesicomyid movements on sediments in the sites colonized by A. gigas seemed to indicate that this species might have a better ability to move. Furthermore, variation in gill sulfur content could reveal a higher plasticity and sulfur storage capacity in A. gigas. Thus, the distribution of vesicomyid species across the chemosynthetic areas of the Guaymas Basin could be explained by differences in biological traits of the vesicomyid species that would allow A. gigas to more easily exploit transient and punctual sources of available sulfide than P. soyoae.

中文翻译：

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贝类物种之间的生态生理差异及其共生体的代谢能力影响深海蛤的分布模式

本研究分析了瓜伊马斯盆地（墨西哥加利福尼亚湾）冷泉和热液喷口区的双壳类双壳类共生体群落分布。结合形态学和分子方法，包括荧光原位杂交 (FISH) 和电子显微镜观察，对蛤类物种及其相关共生体进行了表征，并根据地球化学条件和其他现场观察结果对结果进行了分析。在冷渗区发现了更多种类的 vesicomyids，其中存在三种不同的物种（Phreagena soyoae [syn. kilmeri]、Archivesica gigas 和 Calyptogena pacifica）。相比之下，A. gigas 是唯一在热液喷口区域取样的物种。A 的相同单倍型。在热液喷口和冷渗漏区都发现了 gigas，这突出了相邻喷口和渗流之间可能存在的当代交流。在任一生态系统中，共生体的分子特征证实了共生体和宿主之间的特异性，并支持主要垂直传播的假设。此外，蛤的模式可以反映每个物种的潜在生态位偏好。在 A. gigas 定居的地点的沉积物中出现了大量的 vesicomyid 运动痕迹似乎表明该物种可能具有更好的移动能力。此外，鳃硫含量的变化可能表明 A. gigas 具有更高的可塑性和硫储存能力。因此，