The translucent Dracula minnow, Danionella dracula, is a member of the Cyprininform group of fish, most of which lost their teeth about 50 million years ago. Males of the Dracula minnow species, however, re-evolved fanglike structures that protrude from the jaw bone.
The freshwater minnow was discovered in Myanmar. Scientists say the males use their fangs for sparring with each other. Females lack the vampiresque structures.