Editor's note:
Wild boar is going down the mountain! "Monkey Paper" has arrived at my balcony! News of wildlife entering the city frequently appeared on social media. In fact, we live around us with many native wild animals, who are neighbors, but we rarely know them. Only by understanding, being friendly and accompanying can all things be harmonious and cultivated to achieve success. Xinhua Daily·Jianghuidian, in conjunction with Jiangsu Wildlife Protection Station, Jiangsu Forestry Science Research Institute, Nanjing Institute of Fisheries Science, Nanjing Hongshan Forest Zoo, , etc., launched the "Eye of the Secret Realm·Friends of Humanity" calendar column, which will take you to pay attention to both familiar and mysterious "animal neighbors" through the perspectives of infrared camera , animal observers, etc. Biodiversity is the basis and vitality of human homes. Every solar term day, we will also invite solar term officials to conduct special recommendations and broadcasts on that day. Let’s meet jellyfish today.
body like umbrella
jellyfish is a kind of jellyfish animal, they are a rare variety in jellyfish . The body of the jellyfish is bell-shaped or inverted umbrella. The protruding side is called the upper umbrella surface, and the concave side is called the lower umbrella surface. There is a drooping tube in the center of the lower umbrella surface called the drooping lips. The free end of the drooping lips is the mouth of the jellyfish, and there is a circle of tentacles at the edge of the umbrella. The gastric circulation cavity of the jellyfish body wall is also very developed, with multiple radiation tubes extending from the stomach sac to the edge of the parapet, which gives them a high predation efficiency.
How to move "an umbrella"?
jellyfish rarely perform active displacement movements, but they can still move vertically in the water freely. This is because the jellyfish's myofibrils have separated from epidermal cells to form an independent layer of muscle fibers. Through the regular contraction of these muscle fibers, the umbrella surface can be transformed rhythmically. When the umbrella edge contracts, water in the umbrella edge is sprayed out, and the reaction force generated pushes the jellyfish upwards. When the muscles of the umbrella edge relax, the umbrella returns to its original form, and the water re-enters the umbrella edge, and the jellyfish's body will sink. The horizontal movement of jellyfish is not so free, and is mostly driven by water flow.
jellyfish are "carnivorous" and feed on plankton, small crustaceans, polychaetes and even small fish. In addition to the radiation tube, their stomach sacs also have many gastric silk , which contains a large number of sting cells and gland cells for digestion of food. Jellyfish do not have special respiratory and excretion organs. Both layers of cells in their body walls are in contact with the external environment, so the respiration and excretion can be carried out directly and independently by the body wall cells. The water flow from the outlet, inlet and stomach cavity can carry fresh oxygen and take away the metabolite . The gas they emit is not carbon dioxide , but ammonia.
Detox before eating
Jellyfish is rich in protein , high-quality fat, riboflavin , thiamine, and nutritional elements such as iodine, calcium, iron, and phosphorus. Traditional Chinese medicine believes that jellyfish have the effects of clearing heat and eliminating phlegm, promoting blood stasis and eliminating accumulation, softening hardness and dispersing nodules, nourishing the heart and benefiting the lungs, and it is very suitable for patients with fatty liver and patients with tracheitis , asthma , and gastric ulcer .
Fresh jellyfish contain a lot of water, thick skin, and also contain toxins. It is not suitable to eat it. It needs to be salted with edible salt and alum 3 times (commonly known as 3 alum). After the fresh jellyfish is dehydrated 3 times, the toxins can be drained with the water.
Writer: Jin Yiwei
Map: Zheng Lingling
Picture: Visual China
