A crustacean of order Isopoda, family Ligiidae. It has a pair of long antennae and large compound eyes on its head, and seven pairs of legs.
It lives on seashores and reefs and feeds on algae and dead organisms.
The wharf roaches inhabiting the Big Shell are genetically engineered to help break down the spilled oil. They were created in a lab to help deal with the frequent oil leaks that occurred in the Big Shell.
Their genes have been spliced with genes from the oil-eating Pseudomonas bacterium. The roaches produce an enzyme in their bodies that breaks down oil, enabling them to absorb and eat oil. These roaches are the reason why the Big Shell itself is oil-free. Although they represent a promising form of bio-remediation, they sometimes eat your rations.