Cave-dwelling fish are species that live in dark, underwater caves, often found in regions like Mexico and Thailand. These fish have adapted to their unique environment by losing their eyesight and developing heightened other senses, such as touch and smell, to navigate and find food in complete darkness. One well-known example of cave-dwelling fish is the Mexican tetra, which can be found in the caves of Sierra de El Abra. These fish exhibit interesting behaviors, such as schooling and foraging in groups, which help them survive in their challenging habitat.