The informally named Casper octopus species were first discovered in 2016 in the Pacific Ocean, in water off Hawaii.[1] The two distinct Casper species are new to science but have not yet been formally named with a binomial name as no specimens have yet been collected - they are only known from imagery.[1]
The species gains their informal name from the ghostly white colouring, reminiscent of that of the cartoon character Casper the Friendly Ghost, which scientists think may be a result of lack of pigment in their food.[1] They have short arms, and lack the 'ears' found in the deep-sea Grimpoteuthis species (nicknamed the Dumbo octopuses).[1]
Specimens were observed on footage obtained at depths of 4,290 metres (2.6 miles). It is thought that the females lay their eggs on sea sponges.[1]