This Gloriously Weird Fish Has Teeth on Its Forehead for Sex

This gloriously bizarre fish has teeth on her forehead for sex

By Kate Wong Published by Jeanna Bryner

The spotted ratfish is a fish two feet long with a large head and a long lean tail that lives in the Pacific Ocean of the Northeast. It belongs to a group of fish called chimaeras closely linked to sharks. (Chimaeras are sometimes called ghost sharks.) Like most vertebrate creatures, he has teeth in his mouth. Unlike other vertebrates, he also has teeth in another place: his forehead. He uses these teeth head -on for sex.

The researchers wondered for a long time from which the teeth of the ratfish front come from. New research, published on September 4 in the Proceedings of the National Academy of Sciences USA, has traced their origin.

RATFISH’s additional teeth border a cartilaginous appendage called a teliculum which, in men, can be erected and deployed to grab a female during coupling. Many fish have tight appendages near the pool they use to hold their companion near the act. The spotted ratfish has the ténaculum in addition to the pelvic clasps.

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Scientists know the Tenaculum of RATFISH training for a while. But they did not know exactly how the teeth are from or how they found themselves in this strange place outside the mouth. Many relatives close to the RATFISH – sharks, rays and skates – have dental structures in their skin called denticles which are made of the same material as teeth but which are not real teeth. Are the teeth of the ratfish forehead just modified skin denticles, or do they share their structure and their origin with teeth in the mouth?

To discover it, Karly Cohen of the University of Washington and his colleagues have drawn up the development of the tenaculum of RATFISH using micro-CT scanners and fabric samples, and they compared modern fish with fossil ancestors. The researchers have determined that the teeth of the ratfish front are real teeth – they develop from a structure called dental blade which is present in the jaw but not in skin denticles. The dental blade has never been found outside the mouth so far.

“This crazy and absolutely spectacular characteristic returns the long -standing hypothesis of evolutionary biology that teeth are strictly oral structures,” Cohen said in a press release. Who knows where they will present themselves?

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