Sea stars, or popularly called starfish, are from the phylum Echinodermata and falls under the class Asteroidea. They have five arms and display a seemingly radial symmetry. Sea stars have a movable skeleton that aids them in moving and hunting for preys that include: oysters and clams. One major characteristic of sea star is that they can regenerate lost appendages. However, to produce a new sea star, the arm must be connected to any part of the central disk.
Currently, there are about 1,800 known species of sea star that inhabit all oceans. Majority of sea star species are found in the tropical-temperate waters around the Indo-Pacific regions. Other species live along the cold-temperate water of the North Pacific.
Below is a list of popular sea star species:
Blue Sea Star
It is the most common species amongst sea stars. They live in coral reefs along shallow waters of the Indo-Pacific Region and around the Northern part of Australia. They are blue in color but others bear red or purplish spots along each of its arms. Blue Sea Stars (Linckia laevigata) can reach 30 cm in diameter with 5 tubular arms that are stretched out and typically have short, and yellowish tube feet. Known for its amazing regenerative powers, these creatures can also reproduce asexually and are excellent nocturnal hunters.
Eleven-armed sea star
The Eleven-armed sea star (Coscinasterias calamaria), is widespread to New Zealand and the biggest sea star in southern Australia. They are found mostly hiding in rocks in search of algae during low tides. A beautiful sea star, it is normally blue in color and some individuals bear tints of orange, green, red, gray, cream and white. Although called the Eleven-armed sea star, it can have 7 to 14 arms that can reach up to 30 cm. in diameter. It can reproduce itself by self division– has the ability to generate even an arm into a new individual. Some Eleven-armed sea stars are known to own a set of arms at varying lengths that are capable to generate to its original length.
Spiny Cushion Star
The Spiny Cushion Star (Culcita schmideliana) is a large species of sea star that doesn’t have arms and are found mostly in Indian Ocean; from eastern Africa to Malaysia. It usually grows up to 10 inches in diameter and may come in different colors.
Next to the Giant Sun star, the Crown-of-Thorns starfish (Acanthaster planci) is the second largest species of sea star found mostly in the Great Barrier Reef of Australia, in the Pacific Ocean, Indian Ocean and in the Red Sea. They are solitary animals dwelling in coral reefs and seabed that feeds upon coral polyps using their tube feet. Normally, Crown-of-Thorns starfish have 12 to 19 arms and can grow up to 40 cm. across. Like other sea stars, it is capable of self- regeneration from a battered limb to full sized.
Common Sea Star
This species of sea star is widespread in on starfish in Arctic Norway, the north-east Atlantic and in southern Portugal. They inhibit in shell abundant gravel and rock. Common starfish (Asterias forbesi) colors include: orange, violet or pale brown. They have five arms and is normally 10-30cm (4-12in) across. Some species even grow up to can reach a length of up to 50cm (20in) in diameter.
Giant Sea Star
This species of sea star is commonly found living in rocky sea shores and in seabed along the western shore lines of North America from Southern California to British Columbia. Giant sea stars (Pisaster giganteus) are large species that can grow up to 60 cm. in diameter and come in different colors such as: red, brown or purple. They can live up to 20 years.
Bat Sea Star
Bat Sea Star (Asterina miniata)displays a webbed 5-sided radial symmetry and appears like a bat’s wing. They are found living among rocks and sand bottoms; in the low-tide line up to 290 meters. Bat sea star are abundant from Alaska to Baja California. They can have varying coloration from red, orange, yellow, brown, green, gray and purple. They can grow up to 8 inches in size.