Alicella

Alicella gigantea is the largest species of amphipod ever observed, with some individuals reaching up to 34 centimetres (13 in) long,^[2][3] though more typically just 72.5 to 141 millimetres (2.85 to 5.55 in) and 4.2 to 45 grams (0.15 to 1.59 oz).^[4] Formerly included in the family Lysianassidae, a new family, Alicellidae, was erected in 2008 for Alicella and five related genera.^[5] The species lives only 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,^[6] as well as from the Kermadec Trench in the southwest Pacific.^[3] One specimen was found in the stomach of a black-footed albatross, but is thought to have been scavenged.^[6]

Alicella gigantea
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Malacostraca
Order:	Amphipoda
Parvorder:	Lysianassidira
Superfamily:	Alicelloidea
Family:	Alicellidae
Genus:	Alicella Chevreux, 1899
Species:	A. gigantea
Binomial name
Alicella gigantea Chevreux, 1899 [1]

Compared to other amphipods, A. gigantea grows at a much faster rate.^[4] The size of this species of amphipod is hypothesized to be connected to oxygen availability.^[7] A. gigantea have gills on coxa 7 and tubiliform accessory lobes.^{[clarification needed][7]} These additional structures allow for A. gigantea to absorb more oxygen, which is a known contributor to gigantism.^[7] The size of A. gigantea also allows them to avoid being preyed on by predators such as Notoliparis kermadecensis, a liparid snailfish that preys on smaller amphipods.^[7]