noun
cookiecutter shark; cigar shark
A small deep-sea shark (Isistius brasiliensis) known for taking round, cookie-shaped bites out of larger animals. The Japanese name comes from the round bite marks resembling a Daruma doll.
ダルマザメは深海に生息する小型のサメです。
The cookiecutter shark is a small shark that lives in the deep sea.
クジラの体にダルマザメの噛み跡が見つかった。
Cookiecutter shark bite marks were found on the whale's body.
From 達磨 (daruma, 'Daruma doll') + 鮫 (same, 'shark'), referring to the round, cookie-shaped wounds it inflicts, which resemble a Daruma doll. The exact origin of the name is uncertain.