This order comprises 10000 species of benthic marine and fresh-water crustaceans including the terrestrial wood lice, which are restricted to humid habitats, and the gribble, Limnoria lignorium, which bores into wood causing devastating damage to piers and jetties. Many isopods are parasitic: their limbs are adapted for clinging to the host’s skin; their mouthparts for sucking host tissue. Most isopods are 5 – 15 cm long.
The deep sea Glyptonotus antarcticus is one of the giants of the order. It shows the typical isopod features: dorso-ventral flattening and uniform appendages. These specimens were caught by the Scotia Expedition in 1902.