Alicella

Alicella gigantea is a giant species of amphipod inhabiting the deep sea, which is sometimes referred to as the "supergiant amphipod"; these crustaceans may reach 34 cm (13 in) in length. The only species within the genus Alicella, the species is white in colour and is distinguished from closely related amphipods mainly by size, though subtle anatomical differences can be used for small specimens. They live at depths of around 4,850–7,000 m (15,910–22,970 ft), and their large body size is often presented as an example of abyssal gigantism. Genetic studies into the species have found that it has an exceptionally large genome, which may be linked to its large body size, though this trait's origins are still being investigated.

The species was first collected and described in the 1890s from the Madeira Abyssal Plain off the Canary Islands. Although it is not often observed, A. gigantea is thought to be a cosmopolitan species and can potentially inhabit 59% of the world's oceans. Their diet varies with age, but they are primarily scavengers, consuming carrion. Like other amphipods, female A. gigantea brood their eggs in pouches. Individuals of this species are believed to have unusually long lifespans of over 10 years in age. Despite their habitat's isolation from the ocean surface, human pollutants such as DDT and chlordane have been detected in a number of specimens.