What is the world's largest type of cave-dwelling fish?

The world's largest type of cave-dwelling fish is the Blind Cave Tetra also known scientifically as Astyanax jordani. These fish are endemic to the cave systems in Mexico, particularly in the region of Sierra de El Abra. As their name suggests, they are blind and have no eyes as a result of living in complete darkness for thousands of years. Despite their blindness, they have adapted to the cave environment and use their other senses to navigate and find prey. Blind Cave Tetras are 8 cm (3.1 in) long on average, but some individuals can reach up to 12 cm (4.7 in) in length. They are also transparent and albino due to the absence of pigment. Blind Cave Tetras are passive fish and feed on small invertebrates and algae. Due to the limited food resources in the cave environment, they have a slow metabolism and can survive without food for up to several months. They reproduce by depositing their eggs in rock crevices and pools of water. Blind Cave Tetras have been heavily impacted by human activities such as deforestation, pollution, and groundwater extraction, which have altered the cave environment and threatened their survival. In conclusion, the Blind Cave Tetra is the largest type of fish that lives in cave systems. Their unique adaptations and vulnerable status make them an interesting and important species to study and conserve.