They are the smalles species of dolphins. They weigh 100-120 lbs. (45-50 kg). Sometimes, they are called harbor porpoises.
They travel alone or in small groups. They avoid people and lack the playfulness other species have.
They have black backs and white undersides. They live in cool waters in the North Atlantic ocean and other oceans as well. They are rarely seen in tropics. Sometimes, they swim up rivers for food.
They have been seen in major European rivers which includes:
