How does the ratfish hold on during sex? With its forehead teeth, of course

As It Happens This fish has a forehead full of teeth it uses to hold on during sex

It's not easy to have sex when you're a couple of slippery, limbless fish in the ocean.

But the ratfish has a workaround. The male has a unique, club-shaped appendage on its forehead, called a tenaculum, which it uses to cling to the female's pectoral fin while mating.

Some scientists thought these appendages were lined with the same hard, spiny scales that cover the bodies of the ratfish's distant cousins, sharks and rays. Not so, according to new research.

"No, they're totally teeth," Karly Cohen, marine biologist at the University of Washington, told host Nil Koksal. "Just like the teeth in your mouth or your cat's mouth or in the ratfish's mouth."

The findings, published last week in the Procee