At a black smoker, which organisms are typically found?

At a black smoker, red tube worms are typically found due to their unique adaptations that allow them to thrive in the extreme conditions of hydrothermal vent environments. These deep-sea ecosystems are characterized by high temperatures, high pressure, and the presence of toxic chemicals. Red tube worms, particularly those from the genus Riftia, possess a specialized organ called a trophosome that houses symbiotic bacteria. These bacteria perform chemosynthesis, converting the chemicals released by the black smoker, such as hydrogen sulfide, into energy, which supports the worms and many other organisms in this environment.

The other options, like moss and lichens, jellyfish, or coral reefs, are generally associated with different environments. Moss and lichens typically thrive in terrestrial ecosystems with sunlight and do not survive in the deep, dark ocean. Jellyfish, while present in various marine environments, do not inhabit the specific extreme conditions of black smokers. Coral reefs, too, are generally found in shallow, sunlit waters and rely on photosynthetic organisms, which are not viable in the dark conditions surrounding hydrothermal vents. Thus, the presence of red tube worms is a defining characteristic of life at black smokers, making them the correct choice in this context.