''Ceramaster patagonicus'', the cookie star, is a species of
sea star. It is bright orange or yellow in colour. Its arms are short and it has no spines. It is a deep water species and lives on rocky sea beds. Its diet includes sponges.
Subspecies
The World Register of Marine Species lists four subspecies:
[
*''Ceramaster patagonicus euryplax'' H.L. Clark, 1923
*''Ceramaster patagonicus fisheri'' Bernasconi, 1963
*''Ceramaster patagonicus patagonicus'' (Sladen, 1889)
*''Ceramaster patagonicus productus'' Djakonov, 1950
]
Description
The cookie star is roughly pentagonal in shape with a diameter of up to . It has a slightly inflated, broad central disc and five short rays. The aboral (upper) surface is covered with neatly arranged flat-topped scales, polygonal in the central area and hexagonal on the rays. Between the rays the scales are small and crowded together. There is a marginal row of distinctive larger scales forming a bevelled edge. Sometimes the disc and ray areas are swollen with sunken inter-radial areas between. This may happen when the starfish has recently fed or when its gonad
A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gonad, the testicle, produces sper ...
s are enlarged prior to spawning. The general colour is yellow, orange or pink.
Distribution
The cookie star is found in the Southern Ocean
The Southern Ocean, also known as the Antarctic Ocean, comprises the southernmost waters of the World Ocean, generally taken to be south of 60° S latitude and encircling Antarctica. With a size of , it is regarded as the second-small ...
, the Strait of Magellan
The Strait of Magellan (), also called the Straits of Magellan, is a navigable sea route in southern Chile separating mainland South America to the north and Tierra del Fuego to the south. The strait is considered the most important natural pass ...
and in Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
n and New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
waters.[ It is also found on the west coast of North and South America from ]Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...
southwards to Cape Horn
Cape Horn ( es, Cabo de Hornos, ) is the southernmost headland of the Tierra del Fuego archipelago of southern Chile, and is located on the small Hornos Island. Although not the most southerly point of South America (which are the Diego Ramírez ...
.[ It is a deep water species, in the Southern Ocean being found at depths varying between but is commonest at depths less than .][
]
Biology
The cookie star feeds on sponges
Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through ...
such as the cloud sponge ('' Aphrocallistes vastus '') and the chocolate puffball sponge ('' Latrunculia austini'').[ 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'') is a predatory starfish that feeds on other starfish. If approached by a morning sun star, a cookie star does not attempt to flee, although this would be a pointless strategy as the cookie star is a very slow crawler. The morning sun star climbs on top in its usual attacking position but soon gives up and looks very sick, apparently repelled by a toxic chemical substance. In an experiment, four cookie stars were kept in a tank with a number of hungry morning sun stars for a period of two months, but none were harmed.[
]
References
{{Taxonbar, from=Q1986879
Goniasteridae
Starfish described in 1889