There are two types of otters, but in English the distinction is not very strong. They are both otters. Some live in the sea and are called sea otters. Others live in rivers and are called river otters, or just otters. In Japanese, they have entirely different names. Sea otters are considered very cute because they float on their backs to open clam shells. What kinds of otters have you seen?
Otterには2種類ありますが、英語だとあまり区別する必要がありません。どっちでも「otter」です。海に住んでいるラッコは「sea otter」で、川に住んでいるカワウソは「river otter」又はただの「otter」です。日本語では名前がまったく違います。ラッコは背中で浮いてシャコ貝を開けるからかわいいですね。どんなotterを見たことがありますか?