Cryptasterina pentagona | |
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Scientific classification ![]() | |
Kingdom: | Animalia |
Phylum: | Echinodermata |
Class: | Asteroidea |
Order: | Valvatida |
Family: | Asterinidae |
Genus: | Cryptasterina |
Species: | C. pentagona |
Binomial name | |
Cryptasterina pentagona | |
Synonyms [1] | |
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Cryptasterina pentagona is a species of starfish in the family Asterinidae. It is found in shallow waters in north eastern Australia. Its life cycle includes the release of large-yolked eggs and the development of planktonic larvae which is in contrast to the very similar Cryptasterina hystera which is viviparous. The two appear to have diverged from a common ancestral line only a few thousand years ago. [2]
As its name suggests, Cryptasterina pentagona is pentagonal, with five short rays with rounded tips. The body is covered by an integument and the plates (ossicles) are arranged in a longitudinal series along the rays. There are papulae in a row along the edge of the rays and scattered over the aboral (upper) surface, which is covered by spiky granulations. There are no pedicellariae. The oral (lower) surface is flat while the aboral surface forms a low dome. [3]
Cryptasterina pentagona is native to the tropical Indo-Pacific regions of Indonesia, the Philippines, the Solomon Islands, Taiwan, Japan and the northeast coast of Queensland, Australia. It occurs in the littoral and shallow neritic zone. Its range in Australia extends from Mission Beach to Airlie Beach. It has been reported further south than Airlie Beach, but this may have been a misidentification where it was mistaken for its close relation Cryptasterina hystera. This, although morphologically very similar, has been shown to be a separate species by examination of molecular data. In Australia, Cryptasterina pentagona can be found on the shore of the upper intertidal zone under rocks. [4]
The sexes are separate in Cryptasterina pentagona, and it has the typical life cycle of a broadcast spawner. This involves the release by the female of buoyant, golden, yolky eggs, which are fertilised externally, and the development of brachiolaria larvae. At first these rise to the surface but as they further develop, they sink to the seabed. Here they explore the surface with their rays before deciding on a suitable spot for metamorphosis. Now about nine days old, they attach themselves to the substrate with an adhesive disc. After a complex rearrangement of tissues during metamorphosis, they detach themselves and crawl away as miniature, five-rayed starfish. These new juveniles have two pairs of tube feet on each ray and are an amber colour, indicating that they still have yolk reserves on which to feed. Their mouths do not open for a further three weeks and by that time they have used up the maternal food reserves and the colour has gone. [4]
Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea. Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish are also known as asteroids due to being in the class Asteroidea. About 1,900 species of starfish occur on the seabed in all the world's oceans, from warm, tropical zones to frigid, polar regions. They are found from the intertidal zone down to abyssal depths, at 6,000 m (20,000 ft) below the surface.
The Asterinidae are a large family of sea stars in the order Valvatida.
Leptasterias hexactis is a species of starfish in the family Asteriidae, commonly known as the six-rayed star. It is found in the intertidal zone of the western seaboard of the United States. It is a predator and is unusual among starfish in that it broods its eggs and young.
Acanthaster brevispinus, the short-spined crown-of-thorns starfish, is one of the two members of the starfish genus Acanthaster, along with the much better-known A. planci, the common crown-of-thorns starfish.
Asterias forbesi, commonly known as Forbes sea star, is a species of starfish in the family Asteriidae. It is found in shallow waters in the northwest Atlantic Ocean and the Caribbean Sea.
Anasterias rupicola is a species of starfish in the family Asteriidae. It is found in shallow waters in the Southern Ocean and sub-Antarctic Indian Ocean.
Labidiaster annulatus, the Antarctic Sun starfish or wolftrap starfish is a species of starfish in the family Heliasteridae. It is found in the cold waters around Antarctica and has a large number of slender, flexible rays.
Callopatiria is a genus of starfish of the family Asterinidae.
Ophidiaster granifer, the grained seastar, is a species of starfish in the family Ophidiasteridae. It is found in the Red Sea and the Indo-Pacific and is the only known species of starfish to reproduce by parthenogenesis.
Parvulastra parvivipara is a very small species of starfish in the family Asterinidae. It is a viviparous species and gives birth to live young. It lives in rock pools on intertidal granite rocks in a limited area of South Australia.
Cryptasterina hystera is a species of starfish. It is found in a limited region of the coast of Australia and is very similar in appearance to Cryptasterina pentagona. The two appear to have diverged from a common ancestral line a few thousand years ago.
Nepanthia belcheri is a species of starfish in the family Asterinidae. It is found in shallow water in Southeast Asia and northeastern Australia. It is an unusual species in that it can reproduce sexually or can split in two by fission to form two new individuals. As a result, it has varying numbers of arms, and Hubert Lyman Clark, writing in 1938, stated, "It is a literal truth that no two of the 56 specimens at hand, nearly all from Lord Howe Island, are exactly alike in number, size and form of arms".
Asterina gibbosa, commonly known as the starlet cushion star, is a species of starfish in the family Asterinidae. It is native to the northeastern Atlantic Ocean and the Mediterranean Sea.
Nepanthia is a genus of starfish of the family Asterinidae. Members of the genus have four to seven rays and are found in the eastern Pacific Ocean, ranging from Burma and Indonesia to Australia.
Paranepanthia is a genus of starfish of the family Asterinidae. Members of the genus have five rays and are found in the waters around Australia, Indonesia and Antarctic New Zealand.
Trophodiscus almus is a species of starfish in the family Astropectinidae. It is found in fairly deep waters in the Sea of Okhotsk, the Sea of Japan and around the Japanese island of Hokkaido. It is very unusual among starfish in that it broods its young on its upper surface. Its common name in Japanese is "Komochi-momiji".
Neoferdina cumingi, also known as Cuming's sea star, is a species of starfish in the family Goniasteridae. It is native to the tropical Indo-Pacific region.
Asterina pancerii, commonly known as the seagrass asterina, is a species of starfish in the family Asterinidae. It is native to shallow parts of the Mediterranean Sea where it is usually found in seagrass meadows.
Parvulastra is a genus of starfish belonging to the family Asterinidae. The species of this genus are found in Southern Hemisphere.
Cryptasterina is a genus of starfish belonging to the family Asterinidae. They occur in the Indian and Western Pacific Oceans.