Nepa anophthalma is a species of troglofaunal insect in the Nepidae family, and in the genus Nepa. It holds the distinction of being the only known cave-adapted water scorpion so far discovered. Like with most troglobites, this genus has a limited distribution range, with it only being found in Movile cave, a cave in Romania known for its unique ecosystem supported by chemosynthesis, and with little oxygen. It is often considered a top predator within the aquatic environments of this cave, with very little competition with other animals.