Entering the "flower umbrella world" in the ocean - jellyfish

In the mysterious depths of the ocean, there lives an ancient and fascinating creature. It is like a ghost from another world, with a graceful figure, as if sketching countless dreamy patterns. At the same time, it often appears on the table in the form of delicious food, crisp and delicious, with a long aftertaste, and is deeply loved by people. Can you guess what it is? This issue of the "Meeting in Science" column invites Professor Wang Shuhong and Associate Professor Chen Nan from the College of Fisheries of Jimei University to walk into the "flower umbrella world" in the ocean.

1. What is a jellyfish?

Jellyfish is a type of cnidarian. More than 95% of its body is water . It has stinging cells on its body surface, especially on its tentacles, which are its tools for hunting.

2. How do jellyfish eat without a mouth?

Jellyfish are carnivorous animals that can use their stinging cells or oral arms to catch food and provide it with nutrition . In addition to predation, some jellyfish (such as the upside-down jellyfish) can also provide themselves with nutrition through photosynthesis .

3. How do jellyfish switch between life forms?

Although jellyfish have a simple structure, most jellyfish have male and female differences. Mature male and female jellyfish release gametes, and after the sperm and egg combine, they become fertilized eggs, which then develop into planula larvae . The planula larvae will find a suitable matrix and attach to form a polyp . Under certain conditions, the polyp will form a transverse body , which will release a disc-shaped body as it develops, and the disc-shaped body will continue to develop and become a jellyfish body .

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