rough-toothed dolphin
A species of dolphin (Steno bredanensis) with a distinctive wrinkled tooth surface. The Japanese name literally means 'wrinkle-toothed dolphin'.
Rough-toothed dolphins inhabit tropical seas.
I saw a rough-toothed dolphin at the aquarium.
Katakana spelling is standard for this species name; usually written in kana.
Kanji form is very rare and mostly encountered in specialized or older texts; the word is usually written in kana.
The name is a compound of 皺 (しわ, 'wrinkle'), 歯 (は, 'tooth'), and 海豚 (いるか, 'dolphin'), referring to the wrinkled surface of the teeth characteristic of this species.