A crab with 17 legs? Uncovering the secrets of the mysterious creature "Myoga"

In our daily lives, we are all familiar with crabs. However, a recent news about a "crab with 17 legs" has sparked heated discussions on the Internet. When a netizen was eating a crab, he was surprised to find that the crab had several extra "legs". According to experts, these so-called "extra legs" are actually a creature called "Myoga". So, what exactly is Myoga? Why does it appear on crabs? And why do we rarely encounter it in the crabs we buy? Today, let's find out.

Myoga, commonly known as "sea Buddha's hand", is a marine organism belonging to the phylum Tunicata. It is a close relative of the tunicate, and although they look different, they are both "filter feeders" in the ocean, obtaining food by filtering seawater. This creature has a very unique appearance, with several protruding "finger-like" structures, which can be easily mistaken for the "extra legs" of a crab from a distance. However, these protrusions are actually the water inlet and outlet pipes of the Myoga, which filter small organisms and organic matter in the seawater through these pipes to obtain nutrients.

Xiao Huang, a girl from Hangzhou, once experienced such a terrifying scene. She received a swimming crab sent by a friend from Xiangshan. When she was about to feast on it, she found that the crab gills were densely covered with pink worms after opening the crab shell. These worms were still moving, which made her lose her appetite instantly and even feel nauseous. Xiao Huang's experience is not an isolated case. Many netizens have also shared similar situations, saying that they have found similar worms on the gills of swimming crabs.

It is no accident that myoga likes to attach to the shells of crabs. In the marine ecosystem, myoga and crabs have formed a unique "symbiotic" relationship. For myoga, the crab shell is an ideal habitat. By attaching to the crab, myoga can get more foraging opportunities as the crab moves, and can also use the crab's actions to avoid some natural enemies. For the crab, there is no obvious harm in carrying these "little friends" on its back. This relationship is more like "living together", with both parties getting what they need and living in peace.

According to experts, the scientific name of these pink insects is Myoga, which is not a parasite, but an edible aquatic product. Its meat can also be used as medicine, and many coastal residents often eat it to nourish their bodies. However, the Myoga on the crab gills is relatively small and has little edible value. Researcher Cui Zhaoxia, a crab expert at the Institute of Oceanology, Chinese Academy of Sciences, once said, "It is not a parasite, but an epiphyte, so it will not absorb nutrients from the crab, but appearing in the crab gills will affect the crab's breathing to some extent." Generally speaking, the Myoga attached to the crab gills will not be eaten into the body, because people will remove the crab gills when eating crabs.

Although Myoga is distributed in the Yellow Sea, East China Sea and South China Sea in my country, we rarely encounter them when buying crabs. There are several reasons for this:

1. Myoga has certain requirements for its growth environment. They prefer to grow in specific waters and environments. Not all places where there are crabs will have Myoga. Therefore, the crabs we buy may come from sea areas where Myoga is not distributed, or the number of Myoga is very rare and difficult to be found.

2. Crabs sold in the market are usually cleaned. After being caught, the crabs are rinsed to maintain their appearance and sanitary conditions, and the myoga and other organisms attached to them are generally cleaned. Especially those beautifully packaged crabs are carefully cleaned and selected, and it is almost impossible for them to contain myoga.

3. Myoga grows seasonally, and they are not the same size and quantity throughout the year. In some seasons, myoga may still be in the juvenile stage, small in size, and difficult to find; in other seasons, they may have fallen off or been thrown away by the crab. Therefore, when we buy crabs, it is difficult to find myoga.

For Chinese people, the most concerned question is whether this creature can be eaten. The answer is yes! Myoga is not only edible, but also a nutritious ingredient. It is rich in protein, vitamins, minerals and other nutrients, and has a high edible value. In some coastal areas, Myoga has been served on the table as a special delicacy. It has a fresh taste and unique flavor. It can be steamed, mixed with cold dishes, or cooked with other ingredients to make a variety of delicious dishes.

Myoga is also called gooseneck barnacles. In China, it is called dog claw snails because of its shape like a dog's claw, but large ones are rare in China. In some European countries, it is used as a top seafood ingredient and is expensive. Because it lives in the crevices of island reefs where ocean currents exchange frequently, it is very difficult to collect, so it is also called "seafood from hell." The most plump time for gooseneck barnacles should be in winter.

The "17-legged" crab incident has given us a deeper understanding of the diversity of marine life. The unique creature, Minghe, with its special way of survival and its wonderful relationship with crabs, has revealed a mysterious corner of the ocean world for us. Although we rarely have the opportunity to encounter it in our daily lives, it still plays its role in the ocean and together with other creatures forms a complex and wonderful ecosystem. The next time you taste crabs again, you might as well imagine that maybe in a corner, a crab is swimming freely in the ocean with its "little friend" Minghe!

About the author: Liang Renhai, a teacher at Guilin University of Technology, a senior laboratory technician, an expert in Science Popularization China, and the operator of the Science Popularization China Top 100 account "Guangdong Science Popularization" in 2023 and 2024. He is a member of the China Science Writers Association, a member of the Guangxi Scientist Spirit Propaganda Team, one of the top ten science communication experts in Guangdong Province, a member of the Guangdong Science Popularization Lecturer Team, and a senior youth science counselor of the China Youth Science and Technology Education Workers Association.