Leather Star

Dermasterias imbricata

The leather star is a starfish in the family Asteropseidae found at depths to 100 m off the western seaboard of North America.
A Leather Star Sea Star (Dermasterias imbricata) When our children were much younger (and we were too) and we went to the beach to explore our guide book was “Exploring the Seashore, in British Columbia, Washington and Oregon” written by Gloria Snively. Our edition was printed in 1978 and was purchased in the gift shop on a B.C. ferry while on the way to the west coast of Vancouver Island. That was where we came across our first Leather Star. Ms. Snively says in her book, “It has a peculiar garlic smell.”. This smell is more evident if you scratch the ventral surface. Imagine being a child and finding a “scratch and sniff” sea star! 
By the way, our “Exploring the Seashore” is literally falling apart from use. It was really the only book of its nature giving both common and scientific knowledge... at the time. Canada,Dermasterias imbricata,Geotagged,Summer

Appearance

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 surface is smooth and velvety, 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 25 cm in diameter and has a distinctive smell that resembles garlic and sulphur.
Left High and Dry! These two Leather Stars are waiting for the tide to come up. In fact they may succumb to gravity and fall off this piling that is one of many holding up the Whaletown Dock. Perhaps they were too busy feasting on the barnacles to notice that the tide was falling. The evidence of their feasting is seen by the absence of barnacles in some areas. One of them also seems to be missing an “arm”. Canada,Dermasterias imbricata,Geotagged,Leather Star,Summer

Distribution

The range of the leather star includes the western seaboard of North America from central Alaska to northern Mexico. It lives in the littoral zone and at depths of about 100 m.
A Closeup of the Ventral Surface of Dermasterias imbricata, the Leather Star This closeup shows the madreporite which filters the sea water entering the body of the sea star. Canada,Dermasterias imbricata,Geotagged,Summer

Behavior

The leather star feeds on algae and a range of invertebrates, including other asteroids, bryozoans, sea urchins, sponges, sea cucumbers, hydroids, sea pens, and colonial tunicates. It is in turn preyed on by the morning sun star . 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''. 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.

The parasitic barnacle genus ''Dendrogaster'' is sometimes an endoparasite of the leather star.

References:

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Taxonomy
KingdomAnimalia
DivisionEchinodermata
ClassAsteroidea
OrderValvatida
FamilyAsteropseidae
GenusDermasterias
SpeciesD. imbricata
Photographed in
Canada