Nomura's jellyfish

Nomura's jellyfish (Nemopilema nomurai) is one of the largest jellyfish in the ocean. It lives in the waters of East Asia. It belongs to a group called rhizostome jellyfish and is similar in size to the lion's mane jellyfish, the largest known cnidarian in the world. Nomura's jellyfish is the only species in its genus, making it unique—it is described as monotypic.

People sometimes eat Nomura's jellyfish, but it is not considered a high-quality food. Because of its large size and numbers, it can cause problems for fishing communities. The jellyfish can damage nets and take food that fish need.

Scientists are studying Nomura's jellyfish to find new ways to use it. They are looking at the jellyfish's venom, which might have useful applications in medicine. This research helps scientists understand the jellyfish better and find ways to manage its impact on fisheries.

Description

Nemopilema nomurai can grow up to 2 m (6 ft 7 in) across and can weigh as much as 200 kg (440 lb). This is about the size of a tall person. The jellyfish was named after Mr. Kan'ichi Nomura, who worked at the Fukui Prefectural Fisheries Experimental Station. He sent a specimen to Professor Kishinouye in 1921 for study.

These jellyfish have a clear, whitish body with pink or red parts. Scientists found that some genes in the jellyfish help it swim, showing that its muscles are important for moving.

Distribution

Nomura's jellyfish live in the waters between China and Japan, especially in the Yellow Sea and East China Sea. Their numbers grew more often between 1989 and 2009. Some think this increase might be due to climate change, overfishing, or changes along the coast.

Life cycle

The life cycle of Nomura's jellyfish is similar to that of other jellyfish. These jellyfish are usually found in the Yellow Sea. In June and July, changes in water salinity cause young jellyfish to move through the Tsushima strait. Sometimes, there are large groups of these jellyfish by late October. In just six months, Nomura's jellyfish can grow from the size of a grain of rice to more than 6 feet (1.8 meters) wide.

Ecology

Nomura's jellyfish eat zooplankton throughout their lives. As they grow, they also eat bigger fish. Their predators include swordfish, tuna, sunfish, leatherback turtles, and humans.

Jellyfish blooms are large groups of jellyfish that appear suddenly. These blooms have been seen in the Sea of Japan for a long time. Blooms of Nomura's jellyfish became more common in the 20th century. The largest blooms happened between 2002 and 2003 and caused problems for the fishing industry. In 2009, a large fishing boat turned over while trying to catch these jellyfish in Tokyo Bay, but the crew was safe.

Envenomations

Stings from Nomura's jellyfish can cause itching, swelling, and sharp pain. In serious cases, these stings can be dangerous and might harm health. Scientists are studying the venom to learn more about it and to find ways to help people who are stung. They have found that some special chemicals might help protect skin and muscles from the venom.

Uses

Nomura's jellyfish are appearing more often, so scientists are finding ways to use them. This may help save money for fisheries that lose money because of the jellyfish.

In Japan, people have made ice cream with Nomura's jellyfish, but it must be cleaned and cooked well to be safe to eat. Scientists are also studying the jellyfish for possible medical uses. Some research shows that a substance from the jellyfish might help stop cells from changing in a way that leads to cancer. Another idea is to use the jellyfish to make fertilizer for plants.