The fifth digit on the hind paws is longest, making walking difficult but handy when sculling on its back. 뒷발은 수영을 위한 추진력의 대부분을 제공하기 때문에 평평하고 길며 넓고 완전한 물갈퀴가 있습니다. The muscular tail is reasonably short, thick and somewhat flattened.