Xen- (prefix): Foreign or other. As in: 1  Xenoantigen -- An antigen that is found in more than one species.  Xenograft -- A surgical graft of tissue from one species to an unlike species, genus or family.
Diet. Snow Geese feed almost exclusively on plant material. During the breeding season, they eat many seeds, leaves, and roots of aquatic vegetation. The very young birds feed on invertebrates. Berries become more important in the fall. In winter, waste grain from agricultural fields has become a primary food source.
The crabs live up to 20 years with only the male crabs caught for commercial use. Snow crabs feed on bottom-dwelling sea life, including bivalves, brittle stars and crustaceans, including their own species. They also eat worms, gastropods and several varieties of small fish.