Alicella gigantea is the largest
species of
amphipod ever observed, with some individuals reaching up to long. Formerly included in the family
Lysianassidae, a new family,
Alicellidae, was erected in 2008 for
Alicella and five related genera. The species only lives at great depths; the first specimens were collected at the end of the 19th century from the Madeira Abyssal Plain, and subsequent specimens have been found in other
abyssal plains of both the
Atlantic and
Pacific Oceans, as well as from the
Kermadec Trench in the southwest Pacific. One specimen was found in the stomach of a
black-footed albatross, but is thought to have been dead before it was eaten.