valvatida

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Odontaster validus

…is a species of seastar that is native to the Southern Ocean and the waters around Antarctica. Like other seastars O.validus is a scavenger and will feed on anything it can find. The only thing that O.validus does not attack is members of its own species, this seems to be due to chemoreceptors. It is thought that this helps them congregate en mass to food sources as well. They are also very sensitive to water changes and as such they have undergone much research to help understanding global warming. 

Phylogeny

Animalia-Echinodermata-Asteroidea-Valvatida-Odontasteridae-Odontaster-O.validus

Image(s): Norbert Wu

Beautiful coloured Starfish | ©Lynne Tuller  (Mombasa, Kenya)

This starfish is Pentaceraster mammillatus, a species in the family Oreasteridae (order valvatida), characterized by having interadial spines green with orange tubercles [1].

Sometimes this sea star is called Common Knobbed Starfish. The specific name mammillatus refers to the rows of nipple-like protuberances that cover the surface of the animal and give it a studded or armored appearance.

The known distribution of this starfish covers the Indian Ocean and the Red Sea. In 2008 was documented its presence in Singapore waters [2].

Blue Sea Star by richard ling on Flickr.

Via Flickr:
A Blue Sea Star (Linckia laevigata) resting on hard Acropora coral. Lighthouse Bommie, Ribbon Reef #10, Great Barrier Reef

via scuba-padi.tumblr.com

Crown-of-thorns starfish / オニヒトデ

Acanthaster planci

Crown-of-thorns starfish
This crown-of-thorns starfish is still little. オニヒトデ
このオニヒトデはまだ小さいです。


Animalia Echinodermata Asteroidea Valvatida Acanthasteridae
動物界 棘皮動物門 ヒトデ綱 アカヒトデ目 オニヒトデ科

The picture was taken at Sumida Aquarium, Tokyo, Japan.

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Horned Sea Star (Protoreaster nodosus)

Also known as the Chocolate Chip or Knobbed Sea Star, the horned sea star is a species of oreasterid sea star that occurs in warm, shallow waters in the Indo-Pacific. Like many other sea stars P. nodosus is an opportunistic carnivore and will feeds mainly on sessile invertebrates and other slow moving invertebrates. The “horns” which give P. nodosus its common name are used mainly to deter potential predators by making it look less palatable.

Classification

Animalia-Echinodermata-Asteroidea-Valvatida-Oreasteridae-Protoreaster-P. nodosus

Images: Kareji and Marta Maria Rubio Texeria

2

“Blue Bat Star” (Patiria pectinifera)

…a species of asterinid sea star that occurs throughout the northern Pacific Ocean, along the coasts of Russia, China and Japan. P. pectinifera typically inhabits areas with coarse sediment and/or stony seabeds. Blue bat stars feed mainly on algae, detritus, sea grasses and occasionally small invertebrates.

Petiria pectinifera is commonly used as a model organism in developmental biology as they are easy to maintain and have large and transparent oocytes. Making them mainly used for studies of ooctye development.

Classification

Animalia-Echinodermata-Asteroidea-Valvatida-Leptognathina-Asterinindae-Patiria-P. pectinifera

Images: M.DOĞAN ÖZDEMIR ZAMAN

Biscuit Seastar - Tosia magnifica

Tosia magnifica (Valvatida - Goniasteridae) is a beautiful, large biscuit sea star with up to 16 cm. It is native to Australia, living on sub-tidal rocks and sediment, to depth of 200 m. It is rarely seen and little is known of its biology.

References: [1] - [2]

Photo credit: ©Saspotato (CC BY-NC-SA 2.0) | Locality: Flinders Pier, Victoria, Australia (2009)

Iconaster longimanus - The Icon Star

Also known as Double Sea star, and Iconic star, Iconaster longimanus (Valvatida - Goniasteridae) is one of the most beautiful starfish you can find in the west and central Indo-Pacific Ocean.

This strikingly patterned species has long, thin arms and a flat disk. Like other starfish in Goniasteridae family, Iconaster longimanus has a characteristic double range of marginal plates bordering the disk and arms, that protect the starfish and give it a rigid feel. The plates may be pale or dark and form unique patterns on each individual. 

The aboral surface of the central disk (body) has plates arranged in tessellated manner that form a five-pointed star, hence its common name, Double Sea Star.

References: [1] - [2] - [3]

Photo credit: ©Divaholic

Locality: unknown

Lanzarote - Echinoderm - Smooth Starfish Hacelia attenuata | ©Tony J. Gilbert

Common names: Smooth Starfish, Gladde, Zeester, Étoile de mer, Glatter Seestern, Stella arancio, Estrella de mar lisa.

Hacelia attenuata is a starfish known from the Mediterranean Sea and some localities in the Atlantic .

Animalia - Echinodermata - Asteroidea - Valvatida - Ophidiasteridae - Hacelia - H. attenuata

[Source]

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Cookie Star (Ceramaster patagonicus)

…a species of deep water sea star that is occurs throughout the Southern Ocean, the Strait of Magellan, Australian and New Zealand waters, and on the western coast of the Americas ranging from Cape Horn to Alaska. Like other sea stars the cookie star feeds mostly on sessile invertebrates like sponges. If assaulted by another predatory starfish (like S. dawsoni) the cookie star will not flee and let the star try to eat it, it will then be repelled by a toxic chemical that causes its attacker to retreat.

Classification

Animalia-Echinodermata-Asteroidea-Valvatida-Goniasteridae-Ceramaster-C. patagonicus

Images: NOAA/NMFS and Phil-Sellick

Mosaic Cushion Star - Halityle regularis

The Mosaic Cushion Star, Halityle regularis (Valvatida - Oreasteridae), is a species of sea star distributed in the Indo-West Pacific, characterized by having a pentagonal body with regular triangular papular areas arranged in hexagons, and the arms completely reduced in size. 

Sea stars are frequently inhabited by symbiotic animals of various taxonomic groups, ranging from protists to fish. Halityle regularis has symbiotic relationships with the Starfish Shrimp, Periclimenes soror, and with the polychaete Hololepidella millari.

References: [1] - [2] - [3]

Photo credit: ©Bernard Dupont (CC BY-NC-SA 2.0) | Locality: Tanjung Kubur, Lembeh Strait, Sulawesi, Indonesia (2009)

Vermilion Sea Star (Mediaster aequalis)

…a smaller (76-127 mm [3-5 in]) species of Goniasterid sea star which is widely distributed along the western seaboard of North America, where it ranges from parts of Alaska south to California. Vermilion sea stars are generally found during low/negative tides where they will feed on a wide range of organisms ranging from plant matter to a range of marine invertebrates. 

Classification

Animalia-Echinodermata-Asteroidea-Valvatida-Goniasteridae-Mediaster-M. aequalis

Image: Norwoodpaul

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Pin-Cushion Starfish (Culcita novaeguineae)

…is a species of cushion star found throughout the tropical Indo-Pacific. Like all cushion stars this species sports extremely short arms and an inflated body, so inflated that the arms are barley visible, which makes the echinoderm look similar to a cushion. Cushion stats can often be seen on the bottom where they feed on small invertebrates, corals and organic materials. Like several other starfish species the pin-cushion starfish has a commensal relationship with several species of arthropods which live on the star and clean it. A species of fish has also been recorded living inside the starfish using it as shelter,

Phylogeny

Animalia-Echinodermata-Asteroidea-Valvatida-Oreasteridae-Culcita-novaeguineae

Image Source(s)

Vermillion Biscuit Star - Pentagonaster duebeni

Also known as Australian Biscuit Star, Pentagonaster duebeni (Valvatida - Goniasteridae) is a colorful sea star native to Southern Australia (including Tasmania) which is rarely seen and little is known of its biology.

Reference: [1]

Photo credit: ©John Turnbull (CC BY-NC-SA 2.0)| Locality: The Monument, Kurnell, Inscription Point, Sydney, Australia  (2013)