Fun Fact: Sharks Have Two Penises

posted: 05/04/15
by: Discovery.com Staff
Skate embryo
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Male skates are equipped with two penis-like "claspers", caused by a gene known as Sonic hedgehog.
Jeff Foott/DCL

Did you know that male cartilaginous fish (sharks, rays and skates) are equipped with two penis-like structures, known as "claspers", which channel semen into females during mating?

In a new study, researchers at the University of Florida attribute the growth of the two appendages to a gene known as Sonic Hedgehog (obviously named by Sega enthusiasts). They determined that the gene is expressed for a longer period of time in males than in females, thus causing the growth of the claspers later in fin development.

As part of their study, the team investigated the effect of Sonic hedgehog exposure on skate embryos. When given a Sonic hedgehog inhibitor, male skates did not develop the claspers. When the gene's expression was prolonged in female skates, they began to develop claspers, too.

Learn more about shark reproduction:

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Shark Sex

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