(Kobudai) Asian Sheepshead Wrasse Facts: They Change Gender from Females to Males

The Asian sheepshead wrasse, or Kobudai, is one of the weirdest fish in the ocean. Not only do these species feature weird looks, but they also have a weird ability to change gender. Let’s dive deeper to find out 7 fun facts about these Asian sheepshead wrasses.

Asian sheepshead wrasse - aka Kobudai
Scientific name: Semicossyphus reticulatus
Phylum: Chordata
Class: Actinopterygii
Order: Labriformes
Genus: Semicossyphus

1. The Asian sheepshead wrasse is not easy on the eyes

The Asian sheepshead wrasse is a member of the Labridae family. This reef fish is also known as kobudai and is commonly found in Japan.

This species has many distinguishing characteristics. Their most noticeable feature is its enormous hump on the head. Kobudai, like the hump-head species, has a unique chin. They possess thick lower jaws as well.

The Asian sheepshead wrasse is not a pretty fish
Cre: on pic

To make the species more unsightly, mother nature adds some sharp teeth to them. This unique feature can only be seen in adults.

The bodies of Asian sheepshead wrasse are slender and oval. They are big wrasses that can grow to be 39 inches (100cm). They can weigh up to 32 pounds (14.7kg).

The Kobudai comes with pale pink coloration, however, it can sometimes be brown. In the mating season, they take on a pale tinge near the abdomen and forehead.

The young The Asian sheepshead wrasse

Compared to the adults, the young Asian sheepshead wrasses have a totally different appearance. They lack the chins, the enormous humps on the head, and the teeth. Moreover, they have orange color instead of pink.

They appear intimidating and aggressive due to their large set of teeth and huge size. They are not, however, dangerous to humans.

2. Natural habitat

The Asian sheepshead wrasse is subtropical species of fish. As the name, they’re primarily found in Asian borders and aquatic bodies around Asian nations, particularly near coral reefs. Aside from reefs, they also live in the open seas and in the ocean’s subtidal aquatic floors.

They inhabit mostly Japan, China, Korean Peninsula (Both South and North Korea ), China, and the Ogasawara Islands.

This wrasse species lives in depths ranging from 8 to 20 meters. They also have been known to live as deep as 5 meters. The depth range where they live can vary based on a variety of factors

Being subtropical fish means they need water temperatures of about 78.8 °F (26°C).




3. They live a solitary life

Kobudai lives a lonely life. They are on their own, swimming around coral reef seas and preying on marine creatures. Like other solitary species, they just meet other fish in the breeding season. Males and females pair up for the only purpose – spawning. During this time, individuals join in pairs or groups of pairs. After breeding, they separate and live by themselves again.

These Asian wrasses are extremely friendly to humans. There’s an Asian sheepshead wrasse (named Yoriko) who makes friends with Japanese divers for 25 years.

Like other wrasse fish, the Kobudai communicates with other members by using its body vibrations and movements. They use this way to warn of impending danger or to mate during the reproductive season.

4. Diet

Kobudai is omnivores fish. They eat both animals and plants. They eat oysters, small fish, clams, shellfish, crustaceans, and blue crabs. Their diet also includes chironomid (midges) larvae, zooplankton, and polychaetes.

These Kobudai fish are mostly eaten by larger predators such as sharks. Because the fish are not poisonous, they are often hunted for flesh by humans due to their light flesh and flavor, especially in China, Japan, and Korea.

5. Kobudai are born females

As a wrasses species, Kobudai is sequential hermaphrodite by nature. This means they will change their sex when the time comes.

The Asian sheepshead wrasses fish is born female. However, they can change gender from females to males, depending on the circumstances like there are not enough males in the environment. The time for them to go through a bodily transformation is about a month. The primary goal of this action is to mate.

This process is opposite to that of the clownfish. All clownfish are males and they will change their gender depending on the situation.

Besides clownfish, Kobudai is not the only fish that can change their gender. Here are some other fish that can be gender-bending.

6. Kobudai’s reproduction

The Kobudai reaches sexual maturity at 2 years old. This age is pretty soon when compared to the maturation periods of other wrasse species. The Asian sheepshead wrasse has a fairly low reproduction rate.

These fish mate in the same way that other marine species do. A male and female meet up and create a pair. When becoming a pair to breed, they are very territorial. The biggest male will chase away all other rivals before mating with the female at the surface.

After mating, they find a favorable location for the gestation period. During this time, the pair is typically found around coral reefs.

The female lay eggs and the male release sperms at the same time. Water currents help to fertilize the eggs. These fertilized eggs are observed in coral reef waters.

The Kobudai has a long lifespan. They can live for approximately 20 years. In some literature, the life expectancy of the Asian sheepshead wrasse female is 30 years and 25 years for the male.

7. Conservation status

The Asian sheepshead wrasse is categorized as data deficient by the International Union for Conservation of Nature (IUCN). There’s not enough data about their diet, reproduction, and life cycle.

The exact quantity of this species is still unknown. However, some regular divers and experts indicate a diminishing tendency in their population. The reason for this decline could be Kobudai’s low reproduction rate. Furthermore, they take a long time to mature.


The Asian sheepshead wrasse is a big fish found on the Pacific Ocean’s Asian coast. The first impression about this fish is its huge hump on the head and aggressive face. However, despite the scary look, the Kobudai is friendly and harmless to humans.

There are many aspects of this species that remain unknown, such as its development, reproduction, and population. This fish is a delicious dish for Chinese, Japanese, and Korean.



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1 thought on “(Kobudai) Asian Sheepshead Wrasse Facts: They Change Gender from Females to Males”

  1. I had heard of hermaphroditic fish before, but the Kobudai’s ability to transition between male and female multiple times in its life cycle is mind-blowing. This article opens my eyes


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