This Gloriously Weird Fish Has Teeth on Its Forehead for Sex

image via New Scientist

September 5, 2025, 4:30 PM

• •Spotted ratfish have teeth on their foreheads used for mating.
• •Researchers traced the origin of these teeth to the tenaculum.
• •The teeth are true teeth, originating from the dental lamina.
• •This challenges the traditional view of teeth as solely oral structures.

Researchers have discovered the origin of the spotted ratfish's unique forehead teeth, used for mating. These teeth are located on a cartilaginous appendage called a tenaculum, which males use to grasp females. The study, published in the Proceedings of the National Academy of Sciences USA, reveals that these teeth are true teeth, originating from a dental lamina, overturning the assumption that teeth are strictly oral structures. This finding sheds light on the evolution of teeth and their unusual placement in this fish.

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