Starfish are carnivorous and can eat a variety of invertebrates. In particular, shellfish, crustaceans, polychaetes, etc., and even fish. Some of them are monophagous, for example, many species usually eat only bivalves. There are also polyphagous or omnivorous species.
The Leibniz Institute of Oceanography in Germany has published a bulletin saying that recent research has found that echinoderms such as starfish play an important role in the ocean carbon cycle by being able to absorb carbon directly from seawater in the process of forming their exoskeletons.
The current rapid rise in the number of sea stars is causing great harm to the ecosystem. There are several reasons for this situation, such as:
1. In very suitable sea environments, starfish have a very strong reproductive capacity. The vast majority of starfish are dioecious. Adult females generally lay a very large number of eggs, up to 2.5 million at a time.
2. Starfish have a long life span. Most starfish live for about 10 years, with some species reaching more than 30 years. Among them, the time from juvenile development to sexual maturity is not long, usually less than 2 years to grow up. This undoubtedly increases the population size of starfish significantly.
3. Starfish have a very uncanny ability to regenerate. Even if the starfish suffered external damage, as long as it is not a too serious injury, can be a self-repairing organism.
For example, after a wrist is broken, it can grow back and function the same as before. Some species of starfish, even after cutting off the carapace, only the carapace with a part of the middle part of the basal disc, then will also redevelop into new starfish individuals.
4. Starfish "waste of food" phenomenon is serious. Due to the lack of space in the body of the starfish, its digestive system is not well developed. In particular, the intestinal tract is compressed to a very short point, and the ability to digest the food swallowed into the body is very poor. According to research, starfish eat 100 grams of food, at most can only digest 6 grams of it. The remaining part can only be excreted out of the body. To maintain energy intake needs, the starfish must eat a very large amount of food to do. Most of this food is "ineffective input", and the waste is very obvious.
Controlling the proliferation of starfish has attracted the attention of governments and experts, and it is urgent to reduce the economic loss to shellfish farming.
In Japan, millions of dollars are spent every year to control the harm of starfish, and oyster farms in the United States spend a lot of human and financial resources every year to deal with its harm. At the same time, the harm of starfish has attracted the high attention of governments at all levels.
Experts believe that many disruptions will disappear only when the ecosystem achieves a new balance, and the whole process requires the concerted efforts of multidisciplinary experts, as well as the effective integration of science and policy.
And systematically carrying out marine ecosystem restoration projects is already imminent, which must start with protecting the environment, restoring habitats, and conserving resources, to realize the self-replenishment of marine biological resources.
