Starfishes or Sea Stars, as the marine scientists love to call these water critters, derive their star status from their unique anatomy. They are often confused as fish, whereas in reality, these aquatic creatures are very much unlike their other piscine mates. Sea stars are echinoderms, meaning "spiny-skinned." The spines are small and stubby - not as long and as loud as those on their cousins - the sea urchins. Though they basically inhabit the water regions, their characteristics predominantly differ from that of fish. Starfish are oft thought of as exotic tropical species, but they can be found in cooler regions too. A starfish indeed is a subject of great wonder. Apart from its curious anatomy, there are certain other interesting facets of this water denizen. For instance, it has a mouth, but no head. It can squeeze out its stomach to get a meal. And, it can sometimes grow a twin of itself, from one of its arms. If you wish to unearth more interesting facts and amazing information on this one-of-its-kind aquatic species, read on.
Facts About Starfish
Length: 12-24 cm
Weight: 5 kg
Lifespan: 35 years
Habitat: Shallow to deeper coastal waters
Interesting & Amazing Information On Starfish
- Did you know that the starfish is not a fish? To tell you the truth, unlike the regular fish, it does not have gills, scales or fins and uses its tiny, tube-like feet to swim, instead of tail and fins.
- Starfish are echinoderms, belonging to the class Asteroidea. What makes them a one-of-a-kind aquatic critter is their unique anatomy. A starfish’s body usually consists of five parts or multiples thereof, all symmetrically arranged around a central disk, that makes them look like a star. Hence, the famous name - Starfish or ‘Sea Stars’.
- There are about 2,000 species of sea stars to be found today, lodged all across deep-sea waters. They can be easily spotted in the intertidal zone and tropical areas. However, these sea critters never dwell in freshwater, though there are certain species that can be occasionally found in brackish water.
- One of the most striking characters of this water denizen is its hard, bony, leathery, and spiky skin that serves as protection against most predators. Starfish are usually bright colored, a trait that helps them to guise against possible life threats and even assists them in scaring off predators like birds, sea otters and other fish.
- Quite amazingly, starfish own the unique ability to regenerate lost limbs and at times, their entire body. Since most of their vital organs are located in their arms, they can easily regenerate their whole arm, and at times, create an entirely new sea star just from a severed arm.
- You will be surprised to know that sea stars do not have blood or even brains. In fact, their “blood” is nothing more than filtered seawater. They have a water vascular system, which helps them pump in seawater through madreporite into the tube feet.
- Another amazing fact about starfish is that it has two stomachs. What more, this aquatic creature devours its prey with stomach inside-out! The first stomach, known as the cardiac stomach helps take food outside its body. When the cardiac stomach comes back into the body, the food in it is transferred to the pyloric stomach, which assists in the digestion process.
- Believe it or not, starfish have eyes. Though they cannot see as acutely as humans can, they can at least manage to sense movement and differentiate light from dark. Sea stars have an eye spot at the end of each arm, which appears not more than just a tiny red spot.