Introduction to Jellyfish Author: Aarif Lee Jellyfish Jellyfish is distributed in all waters, including fresh water.
Jellyfish have a short life span. The life span of jellyfish is no more than 2-3 months, and the life span of Peggia and sea squirts is no more than one year. However, our understanding of big jellyfish is still limited. Generally, small jellyfish don't live long.
The common non-toxic jellyfish on the market is spherical jellyfish. Jellyfish-eating jellyfish mostly inhabit warm shallow waters, so it is better to keep them at constant temperature.
Jellyfish will eat phytoplankton on the surface of seawater at the end of photosynthesis, so it is difficult to feed on food sources. Carnivorous type only starts feeding at 8- 12 in the evening, and can feed hatched shrimp. Jellyfish can feed not only newly hatched shrimp, but also Daphnia or rotifer.
The tentacles of tube jellyfish all have stinging cells, which can be used for predation or defense. Some species will have severe pain when stinging people. Some bodies have no stinging cells, but there are rows of comb branches on the side of their bodies. They belong to Ctenomedusae, an exotic species. They swim by waves and produce red fluorescence when swallowing large animals.
Because jellyfish are as poisonous as coelenterates, they are not suitable for raising with other fish except jellyfish. Moon jellyfish in general, the translucent jellyfish on the market is commonly known as Aurelia auriea, and the middle is called Haiyue jellyfish.
They are coelenterates, distributed in warm waters to warm waters of the world's oceans. The center is its stomach; The filaments around the umbrella rim are tentacles, the four belt-shaped wrists under the belly are predatory tools, feeding on plankton, and the body is colloid, containing nearly 98% water.
The appearance can be compared with the pictures added by Ocean Encyclopedia on our website. In addition, be careful not to generate bubbles in the water or the water flow is too strong.
This jellyfish can be raised with ordinary natural seawater. If it is prepared with seawater, its specific gravity is about 1.022.
The pH value of cultured jellyfish must be kept above 7.5. If the pH value is too low, it may be that nitrite is too high due to no filtration, which will endanger the cultured organisms. Please change some water. Source: gj Jellyfish Recently, there has been a craze for raising jellyfish in China. Almost everyone can see people selling in various night markets or small shops and aquariums nearby.
Because of my personal interest, I also went shopping and found that almost all kinds of jellyfish sold in the market belong to "sea moon jellyfish", which is a white transparent disk with a maximum diameter of more than 20 cm. Because it often floats on the sea, it looks like a bright moon in the sea, hence the name. Sea-moon jellyfish are widely distributed in warm waters, and can often be found in the west coast and inner bay of Taiwan Province, especially in spring and summer.
Jellyfish play the role of predator in marine ecosystem. It mainly preys on small zooplankton in the sea area, with stinging cells on its antennae and a large appetite. Therefore, when jellyfish multiply in large numbers, the larvae and eggs of economic fish, shrimps and crabs in this sea area are likely to be eaten up, leading to the depletion of local fishery resources. The breeding mode of sea moon jellyfish is quite special. It is not as rumored that large jellyfish directly give birth to small jellyfish, but two different generations alternate. Generally, jellyfish sold in the market belong to the sexual generation. When jellyfish grow up and mature, male jellyfish will excrete * * into female jellyfish to combine with eggs to form fertilized eggs, and then female jellyfish will excrete and grow into "floating larvae" and grow on aquatic plants or other substrates for a period of time to form "flower worms", which belongs to asexual generation.
Because of this breeding method, jellyfish will gather in bays or lagoons with slow water flow and more food when the water temperature is high and the light is sufficient in spring. But at present, in ordinary shops and aquariums, many small jellyfish are packed in small transparent plastic cups, some are dyed in different colors, and some are packed in small sealed containers to make necklaces for sale.
In order to promote jellyfish, some businessmen brag to the public about how vigorous jellyfish are, claiming that they can live well by dropping one or two drops of their "nutrient solution" every day. What is even more ridiculous is the wrong view that "many small jellyfish can grow after breaking the water matrix". Seeing this phenomenon, we can't help but sigh that those people are so contemptuous of life in order to make money, setting a bad example and negative education for our young students.
Many people also rushed to buy out of curiosity. Because most of them don't know much about the ecological habits of jellyfish, the jellyfish are kept for a day or two, and they are slow for a day or two.
2. Information about jellyfish
Jellyfish (English name: Jellyfish) is an important plankton in the aquatic environment, belonging to the class Mycelia. Jellyfish is a very beautiful aquatic animal. Its shape is like a transparent umbrella, and the diameter of the umbrella is large or small. The diameter of the umbrella of the big jellyfish can reach 2 meters. There are some whisker-like tentacles on the edge of the umbrella, and some tentacles can be as long as 20-30 meters.
The main component of jellyfish body is water, which is composed of endoderm. There is a thick interlayer between the two layers, which is not only transparent, but also floating. When they are moving, they use the reflection of water in their bodies to move forward. Seen from a distance, they float fast in the water like a round umbrella. Some jellyfish have umbrellas with colorful patterns. In the blue ocean, these swimming jellyfish of different colors look very beautiful.
They live in tropical waters, temperate waters, shallow waters, oceans about 100 meters deep, and even fresh water areas. Jellyfish existed 650 million years ago, even before dinosaurs. There are more than 250 species of jellyfish in world waters, which are distributed in waters all over the world.
3. Information about jellyfish
Jellyfish (jellyfish) is a kind of lower marine invertebrate zooplankton and carnivore. Taxonomically, it belongs to coelenterata (also known as Echinotheca) and Scyphozoa, with about 200 known species.
Or species of Cubozoa, which used to be considered as an order of Cephalopods. The term jellyfish also refers to jellyfish-like (bell-shaped or dish-shaped) stinging animals in a broad sense, such as hydra jellyfish, tube jellyfish (including curly-tailed jellyfish), ctenophore jellyfish and sea urchin, which do not belong to algae-eating class.
This kind of jellyfish can be divided into two types: free-swimming jellyfish and settled species (attached to algae and other objects through stalks). Hydra-like species living in a fixed life constitute the order Stauromedusae.
Jellyfish is shaped like a transparent umbrella with different diameters. The diameter of mother jellyfish's umbrella can reach 2 meters. There are some whisker-like strips on the edge of the umbrella, which are called tentacles. Some tentacles can be as long as 20 to 30 meters, which is equivalent to the length of a big whale.
Jellyfish floating in the water extend long tentacles around them, and some jellyfish also have umbrellas with various patterns. In the blue ocean, these swimming jellyfish of different colors are very beautiful.
Jellyfish appeared before dinosaurs, dating back to 650 million years ago. There are many kinds of jellyfish, about 250 species in the world, with diameters ranging from 10 cm to 100 cm, which are common in the oceans all over the world.
There are about 8 common species in China, namely, Haiyue jellyfish, Baixia jellyfish, jellyfish, jellyfish and so on. People often classify them according to different umbrellas: some umbrellas emit silver light and are called silver jellyfish; Some umbrellas are like a monk's hat, called a monk's hat jellyfish; Some umbrellas are like white sails on a ship, called sail jellyfish; Some are like umbrellas, called umbrella jellyfish; Some umbrella-shaped bodies shine with rosy clouds, which are called chardonnay jellyfish ... most of them can only live for a few weeks, and some live for about a year. Some deep-sea jellyfish can live longer.
The umbrella of ordinary jellyfish is not very big, only 20~30 cm long, but the giant umbrella of the larger summer jellyfish can reach 2 meters in diameter and the drooping tentacles can reach 20~30 meters. 1865, a jellyfish was washed ashore on the coast of Massachusetts, USA. Its umbrella is 2.28 meters in diameter and its antenna is 36 meters long.
Pull the tentacles of this jellyfish apart. It is 74 meters long from the tip of one tentacle to the tip of the other. Therefore, it can be said that jellyfish is the longest animal in the world.
There are about 250 species of jellyfish in the world, ranging in diameter from 10 cm to 100 cm, which are common in the oceans all over the world. Chrysaora species swim freely and are found in all oceans, including the common discoid animals drifting along the coastline.
Most of them only live for a few weeks, and some live about 1 year. The diameter is generally 240 cm (1 16 inch), but some species are quite large, and the diameter can reach 2 meters (6.6 feet).
The body composition is 99% water, because the main body of almost all species is made of jelly. Most of them prey on small animals with spiny filaments on their antennae.
Some species filter microorganisms and plants in water. Like all echinoderms, the body is composed of endoderm, and there is an interlayer between them (connective tissue layer composed of colloidal substances).
The mesothelium of jellyfish is thicker and more transparent than that of other echinoderms. The life history of free-swimming true jellyfish can be divided into three periods.
Immobilized hydra can reproduce asexually, split horizontally into larvae from top to bottom at the bowl mouth, and then split into discs, and each disc-shaped body length becomes an adult. Adults are male and female, but some species often change sex.
Embryos formed by the combination of many kinds of sperm and eggs hatch into floating larvae in the digestive tract of adults, but some of them develop in seawater. After leaving their parents, the floating larvae are fixed and grow into new bowl-mouth larvae after a short period of so-called tube larvae.
This life history is unique to Semaeostomeae, with about 50 species, mainly distributed in coastal areas, and some species are widely distributed. For example, Aurelia, Chrysaora, and scarlet jellyfish (Tiburonia granrojo, belonging to Tiburoniinae) are one of the three tentacleless jellyfish.
There are about 30 species of Guansuborder, mostly distributed in the deep sea, often reddish brown. The body is bell-shaped, defined by a deep annular groove between the middle part and the peripheral part of the body, and the peripheral part is divided into many wide petals.
The edge tentacles are big and strong. There are several species in the larval stage, but the life history of most species is unknown.
The crested jellyfish is the most primitive existing basin jellyfish, which may be the offspring of cone jellyfish. Conifer jellyfish flourished from1.800 million to 600 million years ago, and now only fossils are left.
Several crested jellyfish have fixed branches and were once classified as a genus (Stephanoscyphus). There are about 80 species of Rhizostoma.
Mouth and wrist are wrinkled protrusions extending downward from the lower part of the body, which become roots and block the mouth, forming sponge-like areas for filtering food. No tentacles.
The gel-like bell-shaped body is solid and has tumors. People with known life history have a typical benthic larval stage.
Most species in this project are good at swimming; But some (such as 〔Cassiopea Aurelia〕) don't swim often, but put them upside down in tropical shallow water to let the natural photosynthetic algae get light. This species mainly lives in tropical to subtropical shallow waters in the Indian Ocean-Pacific Ocean, but Rhizostoma (also known as soccer jellyfish) is common in colder waters. Cotylorhiza is common in the Mediterranean.
Cruciferae (formerly known as Lucernariida) is not a true jellyfish in the strict sense, with about 30 species, stalks and fixed lives. Living mainly in cold water.
Cup-shaped, with a fixed base handle and a mouth at the upper end. Diameter 1 10 cm (0.44 inch).
There are 8 groups of antennae on the upper edge, which are four radial. Some species can be detached from the fixed point and can be re-fixed.
They often prey on small marine animals and survive for several years. Direct development from larva to adult.
Hydra stage is not obvious. Cubaea has only one purpose, chironex fleckeri, which some biologists still classify as Potomalida.
About 50 species are known. Although some species have a diameter of 25 cm (10 inch), most species have a diameter of 24 cm (12 inch). The body is spherical, but the side is square, so it is commonly called box jellyfish.
Sea bee jellyfish (.
4. The short story of jellyfish's revelation
Enlightenment of jellyfish:
After years of research and observation, scientists finally found that jellyfish have a special set of hearing organs. Before the warning of the storm at sea, the air and waves rub against each other, producing a vibration that people can't feel. The vibration will impact the auditory stone on the jellyfish, and the auditory stone will impact the nerve receptors of the jellyfish, so that the jellyfish can anticipate the coming storm. Scientists imitated the receptors of jellyfish and invented a storm predictor, which can generally predict storms about 15 hours in advance. To ensure the safety of maritime navigation. Nature is a magical book, waiting for you to discover it. It will give us inspiration and let us invent and create.