The leather star (''Dermasterias imbricata'') is a sea star in the family Asteropseidae found at depths to off the western seaboard of North America. It was first described to science by Adolph Eduard Grube in 1857.

Description

The leather star has a broad central disc and five plump, short arms which taper broadly from the central disc. The arms have two rows of tube feet and no bordering marginal plates. The upper, aboral, surface is smooth and velvety, made more so by the absence of spines and a light layer of mucous. It is covered with a reticulated pattern in reddish-brown, often with patches of greyish-blue. No pedicellariae are present, but the madreporite can be seen. This starfish can grow to about in diameter and has a distinctive smell that resembles garlic and sulphur.Marine Biodiversity of British Columbia
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Distribution and habitat

The range of the leather star includes the western seaboard of North America from Cook Inlet, Alaska to northern Mexico. It occurs in Puget Sound. It lives in the

intertidal zone The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species o ...

and in deeper water down to depths of about . It is found on rocky bottoms and occasionally sandy seabeds.

Biology

Dermasterias imbricata (4628744017) (cropped)

The leather star feeds on

algae Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...

and a range of invertebrates, including other

asteroid An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...

s, bryozoans,

sea urchin Sea urchins () are spiny, globular echinoderms in the class Echinoidea. About 950 species of sea urchin live on the seabed of every ocean and inhabit every depth zone from the intertidal seashore down to . The spherical, hard shells (tests) of ...

s, sponges,

sea cucumber Sea cucumbers are echinoderms from the class Holothuroidea (). They are marine animals with a leathery skin and an elongated body containing a single, branched gonad. Sea cucumbers are found on the sea floor worldwide. The number of holothuria ...

s, hydroids, sea pens, and colonial tunicates. It is in turn preyed on by the

morning sun star ''Solaster dawsoni'', the morning sun star, is a species of starfish in the family Solasteridae. It is found on either side of the northern Pacific Ocean. It has two subspecies: *''S. d. arcticus'' Verrill, 1914 *''S. d. dawsoni'' Verrill, 1880 ...

(''Solaster dawsoni''). In its attempts to evade this voracious predator, it crawls away at a maximum speed of 15 cm/min, but this is too slow, and leather stars make up 50% of the diet of morning sun stars. Off the Washington coast, spawning is from April to August. The females release yellow eggs which are fertilized in the water column. The larvae then become part of the zooplankton. The leather star sometimes lives symbiotically with the scaleworm ''

Arctonoe vittata ''Arctonoe vittata'' is a species of scaled polychaete worms commonly known as a "scale worm". This species often lives as a commensal of another marine animal. Description At least thirty pairs of elytra, scale-like modifications to the dorsal ...

''. The worm also associates with various other marine invertebrates, but if separated from its host, will search out another member of the same species. The worm may nip off the heads of small tube-dwelling polychaetes as the starfish moves around, but is not harmed by its host.''Arctonoe vittata''
The parasitic barnacle genus '' Dendrogaster'' is sometimes an

endoparasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has c ...

of the leather star.

References

{{Taxonbar, from=Q2618140 leather star Western North American coastal fauna leather star leather star