in taxon Cetacea external naris blowhole blowhole slit UBERON:0013477 Baleen whales have two blowholes positioned in a V-shape while toothed whales have only one blowhole. The blowhole of a sperm whale, a toothed whale, is located left of centre in the frontal area of the snout, and is actually its left nostril, while the right nostril lacks an opening to the surface despite the fact that its nasal passage is otherwise well developed. Wikipedia:Blowhole_(anatomy) A hole at the top of a cetacean's head through which the animal breathes air.