noun
Dall's porpoise
A species of porpoise (Phocoenoides dalli) found in the North Pacific. The name is usually written in katakana.
イシイルカは北太平洋に生息している。
Dall's porpoises inhabit the North Pacific.
船の近くでイシイルカの群れが見られた。
A pod of Dall's porpoises was seen near the ship.
The name likely derives from いし (stone) and いるか (dolphin), but the exact origin is uncertain.