Kurilean aglah constitution differs considerably from its ancestor. It is a large beast - body length of about 140 cm, tail - up to 60 cm have aglaha massive body, short and almost plantigrade paws with fingers wide apart, connected by the swimming membrane.. The large claws are used for food production and help to cling to the bottom, to resist the waves. This animal swims and dives well, holding the breath for 10 - 12 minutes. This shortened the animal's ears are closed skin folds.