Giant isopod (Bathynomus)
A giant isopod is any of the almost 20 species of large isopods (crustaceans distantly related to the shrimp and crabs, which are decapods) in the genus Bathynomus. B. giganteus reaches an average length between 19 and 36 cm,with a maximum weight and length of approximately 1.7 kilograms and 76 centimetres. Giant isopods are a good example of deep-sea gigantism (cf. giant squid). Though most other species of Bathynomus apparently are smaller, they are nevertheless far larger than the “typical” isopods that range in size from 1 to 5 cm. Like the woodlouse, they also possess the ability to curl up into a “ball”, where only the tough shell is exposed. Although generalist scavengers, these isopods are mostly carnivorous and feed on dead whales, fish, and squid; they may also be active predators of slow-moving prey such as sea cucumbers, sponges, radiolarians, nematodes, and other zoobenthos, and perhaps even live fish.