In the marine ecological environment, jellyfish, like fish, is a very important part of the food chain. However, the nutrients it provides to predators seem a little different. The jellyfish is almost completely transparent, and 97% of the body’s volume is made up of water. In addition, they are free of carbohydrates, fats and proteins. These three nutrients are key substances that provide energy and nutrients to organisms.
But to the surprise of the scientists, they observed that jellyfish were preyed on by a large number of organisms. For example, common sea moon jellyfish are preyed upon by fish, turtles, seabirds and even their own kind – omelette jellyfish and large otter jellyfish. They can’t help but wonder if these creatures have accidentally or intentionally eaten jellyfish. Do you just want to just add some moisture?
In fact, behind this phenomenon, it is revealed that the dietary balance that is prevalent in the biological world. In addition to the three main energy-supply substances (carbohydrates, fats and proteins), we need to consume a variety of vitamins, minerals, and some rare nutrients in addition to the three main energy-supply substances. A large number of studies have shown that not ingesting or eating less nutrients can lead to a variety of physiological abnormalities or strange diseases. This phenomenon may also exist in the marine life chain.
Jellyfish contain rare fatty acids
Fats hoarded in humans and other organisms are made up of glycerin and fatty acids. Among them, fatty acids are divided into saturated fatty acids and unsaturated fatty acids. Although unsaturated fatty acids are only a few less hydrogen atoms in the carbon chain (less oxidizing), their benefits to the human body are much higher than those of saturated fatty acids. In addition to providing energy, they can also participate in the body’s signaling pathways, promote the growth of somatic cells, and convert them into other essential components of the body as precursors.
When the researchers analyzed frozen sea moon jellyfish, they found that they were rich in fatty acids, of which unsaturated fatty acids accounted for as high as 42.9% to 54.7%. The sex glands are the most fatty acids relative to the rest of the body. Three of the unsaturated fatty acids attracted the attention of researchers: ARA, 20 carbon pentaeric acid (EPA) and 22 carbon hexaleic acid (DHA), of which ARA is an omega-6 fatty acid, EPA and DHA are omega-3 fatty acids.
At present, scientists are well aware of the value of ARA, EPA and DHA to the human body, especially their health benefits of promoting brain development and maintaining heart health. Humans can synthesize these fatty acids through specific biological pathways, but because of the small amount of synthesis, they also need to be supplemented appropriately through diet. The deep-sea fish oil, which is widely available from these three fatty acids, may be a good choice. However, these fatty acids are not all synthesized by these marine fish.
For the vast majority of organisms, including humans, there are not enough enzymes in the body to help them convert some compounds into nutrients that meet their needs. These nutrients, also known as essential nutrients, need to be taken from specific foods. For example, most of the DHA that exists in deep-sea fish is passed through the food chain step by step. The original sources of DHA in the ocean were algae in the sea, such as Ko’s hidden algae and cracked pot algae.
In this food chain, the sea moon jellyfish also transmits valuable rare fatty acids to the large number of predators located above it. Using these unsaturated fatty acids, predators can achieve important physiological activities, such as inhibiting allergic reactions, inflammatory responses, and achieving neuroactivity, immune function, and reproductive function. The researchers found that the sea moon jellyfish also had the advantage of providing a wide range of fatty acids to predators at different stages of growth, such as maturation and immaturity. As a result, they believe that sea moon jellyfish are an important part of their diet for their predators.
Jellyfish aren’t all random prey.
The jellyfish contain almost no nutrients such as carbohydrates, fats and proteins, and they need to be replenished by predatory. The recipes for jellyfish are also extensive, including a variety of plankton, molluscs, diatoms and other jellyfish. Previously, by analyzing digestive enzymes in the body of sea-moon jellyfish, scientists found that they can digest some of the energy materials of food, etc., to feed life activities.
Sea-moon jellyfish generally live in shallow water slowly and move slowly in the water, more like drifting along the sea. As a result, predators can capture and eat large numbers of jellyfish without consuming too much energy. In fact, these predators can’t swim away when they want to get close and prey on the jellyfish. Some researchers have also observed that salmon in the ocean prey on jellyfish 20 times faster than shrimp.
Other studies have found that jellyfish with sexual glands, such as sea moon jellyfish, are more likely to be caught eating than jellyfish without sex glands. In addition to being rich in fatty acids, the latter’s gonads contain more nutrients, which are undoubtedly the reasons for the redness of predators. “We thought jellyfish were more of a random prey for predators,” said Jamileh Javidpour, a marine biologist at the University of Southern Denmark. But the truth is that while predators don’t get much fatty acids when they eat a sea moon jellyfish, they get a lot of fatty acids if they eat a lot. “In each kilogram of jellyfish (dry weight), the total fatty acid content is 7-34 grams. Feeding these jellyfish is also sufficient to meet the demand for fatty acids in many marine organisms.