In the cold waters of the Arctic, the largest member of the sea tuber family is the great tusked yam. Weighing up to two tons, the yams of the north are ungainly on land but sleek and graceful in the water. Both male and female yams have tusks, which they use to root around the sea floor, and very rarely, in combat between large males. The yams travel in large family groups, and while a polar pear may occasionally snag a very young or old and rotten yam, the adult yam has no natural predators. They can often be found sunning themselves on rocky outcroppings in summer, or rooting on the shifting icefloes in winter.
