What is a Starfish?
Starfish is a creature that has managed to attract the attention of many of us due to their visually pleasing and colorful appearance. They are usually used as ornaments when they are dry. Starfish are scientifically called Asterioda. The word meaning is “star-shaped” and was given by a French zoologist in 1830.
It is predicted that the first starfish runs in history dating back to almost 450 million years. This is an ancient history even compared to dinosaurs. For so long, starfish have managed to survive to this day with many shape changes based on evolution.
Where does Starfish Live?
Starfish are resistant to cold seawater due to which they can live even in places at a depth of 6000 meters above sea level and in many regions around the world, from the coldest polar sea waters to the warm tropical sea waters. In addition to being generally red and orange, there are also blue, brown, and gray ones. Starfish cannot live in freshwater. The most common types are observed in areas close to the coasts.
The sea stars we see in the seas in our country are usually orange or red and have 5 branches. However, it is known that there are more than 1,500 starfish in the world with more branches.
How is the Starfish Structure?
Starfish usually have 5 arms and hundreds of feet on each arm. Some of these feet act as suction cups, ensuring very good adhesion. Due to their structure, they can move in all directions. Many are not fast-moving. They can move up to 15 cm per minute. Only one type of starfish can travel 2.7 meters per minute.
Although starfish have no brain it has a very complex central nervous system. There are neural networks that extend around the mouth and arms. All neural networks and ends are sensitive to light and touch so they can perceive.
Thanks to their arms, they can reach their prey and perform the feeding cycle. The starfish, holding the mussels with suction cups on its feet, can open the mussel and eat the soft part inside the mussel. Many starfish eat algae, mussels, sea snails, and sponges.
How Long Are Starfish Lifes?
The life span of sea stars varies according to their types. Starfish reaching early adulthood will have a shorter life. For example, a species with an adult weight of 20 g reaches sexual maturity in 2 years and can last 10 years.
However, another species, which has a heavier adult weight and reaches up to 80 g, reaches sexual maturity at the end of 5 years and has been found to live up to 34 years.
Starfish Ecological Effect
Starfish have important features in ecological marine life and feeding cycle, but some changes cause them to harm ecology as well. Sea stars left in places where there are mussel species that threaten some biological diversity caused a decrease in mussels in three of them for a while and it has been observed to provide balance. However, it is also seen that starfish disrupt ecology. Migrant sea stars, in particular, seriously damage coral reefs. Starfish that feed on corals cause the reefs to disappear significantly. Due to the increasing trade in the world, creatures that will never reach can be transported to many different parts of the world with the ballast waters of the ships. A kind of starfish is thought to have been carried in this way, it covered most of the coral reefs in Polynesia within 3 years.
In addition, a starfish species that reached Tasmania by ships from another region caused endangered endangerment in the region. In that region, starfish are identified as dangerous species.
The vast majority of sea stars reproduce sexually, that is, the female and male sexes. But there are different types of reproductive conditions. It is indistinguishable whether they are male or female. There is a chance to be distinguished during the ovulation period.
Some sea stars can reproduce by dividing. They divide into two, and when they divide, new starfish form.
Some sea stars change gender. Starfish, who spent some of their lives as a male, may start to show female features. But the most interesting breeding type, starfish, are those that incubate. There are also sea stars waiting for incubation, lying on their eggs like chickens.
Threats to the Starfish
Starfish are usually a bait by some of their own species, crabs, seagulls, some fish, and sea otters. To protect these creatures, they have saponins in their bodies that give a bad taste. In some species, a slimy outer layer is secreted, others are covered with sharp spines. Get the chance to live this way
Legends and Culture
A legend told by Australian Aborigines tells how some animals need canoes to cross the ocean, and how the starfish, which refuses to lend its canoe, engage the starfish by telling tales, cleansing the whale’s parasites, and other animals steal the canoe. Understanding that the legend has been deceived, the whale beats the starfish and makes it cannibalism, which still has this shape today.
A common story tells about a man walking by the sea meets a young man who throws the starfish hitting the beach one by one. When asked why he did so, he states that the starfish, which are under the sun, will die with the withdrawal of water along with the young tide. When he asked the young man that there were miles of beaches and thousands of starfish and what this effort would make, the young man leaned over and threw another starfish into the sea and said, “He realized for this.” says.