Barnacles spend their lives glued to rocks, which makes mingling with other barnacles rather difficult. That’s one reason they have penises that are up to 40 times their size –- the biggest penises in the animal kingdom.
The hermaphroditic animals regrow their penises each year, just before their brief mating season.
A study found that water conditions change the shape and size of barnacle dicks.
- In calm water, barnacles grow long and flexible penises.
- Choppy conditions lead to stockier, muscle-bound weenies.