Gender-Bending Barnacles Grow Huge Penises in Rough Waters

Barnacles can radically change the size and shape of their penises to fight the waves and have sex.

Here is the challenge for the tiny hard bodies: Barnacles want to mate but are permanently bound to whatever rock or hull they once latched onto.

Given that, they have evolved the longest penises of any creature for their size — up to eight times their body length — to seek out and have sex with their neighbors. (Most barnacles are hermaphrodites that alternate between male and female sexes over time.)

But large penises can be a problem, what with waves crashing down on the surfaces where these crustaceans often dwell.

Pictured: Artist conception of sex-changing, giant penis barnacle.