A Curious Collection of Peculiar Creatures

The first thing you’ll notice about the Asian sheepshead wrasse (also known as kobudai in Japan) is its bulbous head and chin. We don’t know much about the purpose of these impressive bony growths, which appear only on males, but they might be useful in attracting females during breeding season.

But that’s not the most amazing thing about this fish: A female wrasse can transform into a male halfway through her life! Scientists don’t fully understand why this happens, but they believe it may be a way for the fish to produce more offspring.

The male sheepshead wrasse can reach a massive 3 feet (1 m) long and can weigh up to 32 pounds (14.5 kg). Females are much smaller (before they turn into males, that is!).

Asian sheepshead wrasse live in the cool seas surrounding Japan, China, and North and South Korea, where they’re especially fond of rocky reefs.

Scientists believe this wrasse mainly eats crustaceans and shellfish. This would explain their unusual teeth, which are perfectly designed for chewing through and opening shells.

Unfortunately, there isn’t much information about this species of wrasse, but we do know their population is dwindling. Overfishing will probably endanger them if no limitations are put in place.

The wrasse is also threatened by many chemicals we use to clean our houses. When we pour these down the drain, they can end up in the ocean and may harm the fish’s ability to reproduce.

Fun Facts

Animals that can change genders, whether from male to female or from female to male, are called sequential hermaphrodites. There aren’t many creatures that can do this, though—just certain kinds of fish, snails, and slugs.
It’s difficult to collect data about this species thanks to its gender-fluid ways. A fish that’s recorded as female one day may become male by the next time it’s studied.
When wrasse that were born female change into males, they can grow even larger than wrasse that were born male.