The starfish with Its symmetrical appearance, s the common name given to the echinoderm marine Invertebrates belonging to class Asteroidea Its not hard to understand where the starfish gets Its name from. It has been a subject to many scientific researches as a living organism, played ItS part In literature, legend design and popular culture “lith its eye-catching beauty. and has also been collected as a curio There are seven living subcategories and two extinct subcategories of starfish which have about 1,500 living species all around the world, from tropical regions to frigid polar waters. Starfish can live from the intertidal zone down to abyssal depths, 6.000 meters below surface.
Starfish are star shaped with arms that radiate from a central disk. They typically have five arms, though some species can have a larger number of arms. So much so that some have up to fifty arms. The size of the central disk, number and length of the arms vary from species to species. The distance between the tips of two arms is usually abot 20 ern, however it‘s possible to find species with a 1 cm distance as well as more than 60 cm distance. Most starfish can regenerate broken or damaged arms and body parts, and shed their limbs as a means of defense. Some can regrow an entire new limb, whereas in some species a separated limb can regrow an entire new starfish.
Most starfish species are coloured in various shades of red and orange. While others are in different colours like blue, grey or brown. Just as the most of the echinoderms, the
starfish‘ mouth is at the lower surface, and the excretion hole is at the upper surface of the body. The underside of their arms are hollowed and covered with a great number of short and tapered tubings called tube feet. These tube feet allow the starfish to both move and hunt. Starfish feed on coral polyps, mussels, oysters, water algae, sponges and other small sea creatures. They dig at the soft parts at the bottom of the sea with their tube feet to reveal mussels and oysters. After enveloping the mussel or oyster with its arms, the starfish separates the two valves slightly, and inserts a small section of its stomach to eat the soft part inside the mussel, and digests the prey.