Vitreledonella richardi, also known as the glass octopus, is an incirrate octopus. It is the sole representative of the genus Vitreledonella and of the family Vitreledonellidae. Vitreledonella is a transparent, gelatinous, and almost colorless meso- to bathypelagic octopod found worldwide in tropical and subtropical seas with a mantle length (ML) up to 11 cm and a total length up to 45 cm in adults. The upper three pairs of arms are subequal in length; in juveniles about as long as the mantle, in adults two to three times ML. The fourth, ventral pair is slightly shorter. Suckers are small, widely separated, and in a single series. In males, the left arm III is hectocotylized, with a spherical vesicle near the tip, but is not detachable. Eyes are nearly rectangular in shape as seen from the