Telescopefish are deep-sea aulopiformes, a diverse order of ray-finned fish. As of 2025, there are two recognized species of telescopefish, which are Gigantura chuni and Gigantura indica. Both species have an almost startling appearance, with faces dominated by telescope-shaped eyes.

Chun’s Telescopefish (Gigantura chuni) These are scaleless, silvery, and elongated fish with a ribbon tail. They have been recorded off Dampier in Western Australia and in the tropical waters of the Atlantic, Indian, and Pacific Oceans. Adults are found between 1,640 and 6,561 feet.

They swim vertically with their heads up, using their large eyes to detect the silhouettes of prey above. Because they are synchronous hermaphrodites, they can produce both sperm and ova, increasing their chances of reproduction in this challenging environment.

Indian Telescopefish (Gigantura indica) These fish are also slender and slightly tapered, with large eyes. Close up, they look like a very scary alien! They have been recorded north of Port Hedland, Western Australia, off northern Queensland, and near Norfolk Island in the Tasman Sea. They are found circumglobally in tropical to subtropical waters. Adults occupy the mesopelagic and upper bathypelagic zones. They also swim vertically, looking for prey, and are synchronous hermaphrodites.