''Eucidaris thouarsii'', the slate pencil urchin (named after
slate pencil
A slate is a thin piece of hard flat material, historically slate stone, which is used as a medium for writing on. Writing on a slate is impermanent and easily erased, and the same slate is then reused.
Usage
The writing slate consisted of a ...
), is a species of cidaroid
sea urchin
Sea urchins or urchins () are echinoderms in the class (biology), class Echinoidea. About 950 species live on the seabed, inhabiting all oceans and depth zones from the intertidal zone to deep seas of . They typically have a globular body cove ...
s that inhabits
littoral
The littoral zone, also called litoral or nearshore, is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely i ...
regions of the East
Pacific Ocean
The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...
.
Distribution and habitat

''Eucidaris thouarsii'' is found in the East Pacific at depths of , ranging from
Baja California
Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...
to
Panama
Panama, officially the Republic of Panama, is a country in Latin America at the southern end of Central America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and ...
, as well as
Cocos Island
Cocos Island () is a volcanic island in the Pacific Ocean administered by Costa Rica, approximately southwest of the Costa Rican mainland. It constitutes the 11th of the 15 districts of Puntarenas Canton of the Puntarenas Province, Province of ...
,
Clipperton Island
Clipperton Island ( ; ), also known as Clipperton Atoll and previously as Clipperton's Rock, is an uninhabited French coral atoll in the eastern Pacific Ocean. The only French territory in the North Pacific, Clipperton is from Paris, France ...
and the
Galápagos Islands
The Galápagos Islands () are an archipelago of volcanic islands in the Eastern Pacific, located around the equator, west of the mainland of South America. They form the Galápagos Province of the Republic of Ecuador, with a population of sli ...
. The Galápagos, Clipperton and Cocos populations are now often recognized as a separate species, ''
E. galapagensis'', instead of a
subspecies
In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...
of ''E. thouarsii''.
Diet
Like all urchins these are primarily herbivores, but feed on a wide range of invertebrates. This species has a high nutrient absorption efficiency when it comes to the coral
Pocillopora damicornis
''Pocillopora damicornis'', commonly known as the cauliflower coral or lace coral, is a species of stony coral in the family Pocilloporidae. It is native to tropical and subtropical parts of the Indian and Pacific Oceans.
Description
''P. damic ...
, but would require a large intake to make nutrient requirements. Due to its high intake of coral, it reduces reef growth.
References
External links
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Echinoderms described in 1846
thouarsii
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