Beyond the Surface: Evolutionary Insights into Thiothrix Symbiosis Across Extreme Habitats

Symbiotic relationships are frequent in extreme environments characterized by hydrogen sulfide and low oxygen levels (such as sulfidic caves and hydrothermal vents). A variety of invertebrates living in sulfide-rich marine habitats display physiological adaptations to such environments, some of which involve microbial symbionts (Anderson et al., 1987;Wilmot & Vetter, 1990; Cavanaugh et al., 2006; Dubilier et al., 2008; Tokuda et al., 2008; Petersen et al., 2010; Pakes et al., 2014; Sun et al., 2022). Compared to hydrothermal vents, sulfidic caves