Have you ever seen a creature that spits out its stomach and eats? Do you know where starfish's eyes are? After reading this article, you will have a certain understanding of starfish.
Starfish are strange and beautiful creatures in the ocean, they come in a variety of colors, shaped like stars in animation, the most common starfish have five arms, but some of these varieties can grow up to 40 arms.
In fact, this amazing marine creature belongs to the echinoderms, which move through the tubular foot, can regenerate after losing the arm, and can swallow food larger than itself.
Starfish are not fish
Although starfish live underwater and are often referred to as "starfish", they are really not real fish. They do not have gills, scales or fins like fish.
Starfish also move very differently than fish. As the fish push forward with their tails, starfish have tiny tubular feet to help them move forward.
Starfish are echinoderms
Starfish belong to the echinoderm phylum. This means that they belong to the same family as sea urchins, sea cucumbers and other animals.
In total, this phylum contains about 7,000 species. A large number of echinoderms exhibit radial symmetry, meaning that their body parts are arranged around a central axis.
As a result, many starfish have five-point radial symmetry because their bodies have five parts. This means that they have no distinct left and right halves, only the apical and undersides. Echinoderms usually have spines, which are less pronounced in starfish than sea urchins.
There are about 2,000 species of starfish in the world
There are about 2,000 species of starfish worldwide. Some live in the intertidal zone, while others live in the deep waters of the ocean. Most of these live in the tropics, but starfish can be found in cold regions and even in the polar regions.
Not all starfish are "five-pointed" stars
Multi-armed sun star
Although many people are most familiar with the five-armed species of starfish, not all starfish have only five arms. Some species have more arms, such as the Sun, which can have as many as 40 arms.
Starfish arms can regenerate
Surprisingly, starfish can regenerate lost arms, which is effective for starfish in dodging predators.
Most of starfish's vital organs are on the arm. This means that some starfish can regenerate a new starfish through one arm. But the process is slow, and it takes about a year for an arm to regenerate.
Starfish are protected by thick "armor"
Thorn-crowned starfish
Depending on the species, skin with starfish may feel like leather, or a little prickly. The upper side of the starfish has a hard covering, consisting of calcium carbonate plates with tiny spines on the surface.
Starfish's spines are used to protect themselves from predators, including birds, fish, and bird sea otters. A very spiny starfish is aptly named the thorn-crowned starfish.
Starfish have no blood
Starfish have no blood, and their fluid circulation system consists mainly of seawater.
Seawater is pumped through a sieve plate into the animal's water vessel system. This is a trapdoor called a sieve plate, and a light-colored spot can usually be seen on top of the starfish.
The seawater enters the feet of the starfish, causing the arms to stretch. The muscles within the tube foot are used to control the contracted limb.
Starfish move with tube feet
Starfish thin tube foot
Starfish uses hundreds of tube feet located on its underside to move. The foot of the tube is filled with seawater, which is brought in by starfish through a sieve plate at its top.
Starfish are moving faster than you think.
If you have the chance, go to the beach or the aquarium and take a moment to observe the movement of a starfish, which you will find is one of the most amazing sights in the ocean.
Tube feet can also help starfish catch prey, including clams and mussels.
What do starfish eat? How to eat?
Starfish prey on bivalves such as mussels, clams, and small fish, snails, and barnacles as food.
Starfish have a unique way of prying open shellfish shells.
The starfish's mouth is underneath it. When it grabs food, the starfish wraps its arms around the animal's shell and gently pulls it away. The next step would be startling— the starfish pushed its stomach out of its mouth into the bivalve's shell. It then digests the animal and slides its stomach back into its own body.
This unique feeding mechanism allows starfish to eat larger prey than it could have stuffed into its small mouth.
Starfish also have eyes
Starfish have eyes, growing at the ends of their arms, in the most unexpected places.
Starfish have an eye spot at the end of each arm. This means that a five-armed starfish has five eyes, while a forty-armed sun star has forty eyes.
Each starfish eye is simple and looks like a red dot. It can't see much detail, but it can sense light and darkness, which is enough for creatures living on the ocean floor.
Starfish breed in a special way
The genders of starfish are difficult to distinguish because they look exactly the same. While many animal species reproduce in only one way, starfish are a little different.
Starfish can reproduce sexually. They are put into water by releasing sperm and eggs (called gametes). Sperm fertilize gametes and produce swimming larvae that eventually settle on the ocean floor and grow into adult starfish.
Starfish can also reproduce asexually by regenerating, which is what happens when an animal loses an arm.
starfish... Can I eat it?
This is said directly to the practice
1. Steamed starfish
Directions: Buy fresh starfish, rinse it, put it in the steamer, steam it in water, steam it for about 15 minutes after the pot is opened, you can take it out and plate it; when you eat it, you need to take out the seeds inside the starfish, and then you can eat it directly.
2. Scrambled eggs with starfish leeks
Directions: First cook the starfish and remove the seeds inside, then mix well with the eggs, then wash the leeks and cut them into segments for later use; heat the oil in the frying pan, put the above three ingredients together into the pot, fry into a lump and add salt to taste.
3. Starfish lean broth
Method: First of all, prepare 4 to 5 starfish, 200 grams of lean meat, wash the lean meat and cut it into pieces, put it into the pot with the washed starfish, add the appropriate amount of ginger and green onion and dates, and then add enough water to cook together into the soup.