''Stomopneustes variolaris'', the black sea urchin or long-spined sea urchin, is a species of
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 ...
, the only one in its genus ''Stomopneustes'' and only species still alive in its family
Stomopneustidae. It is found throughout the tropical Indo-Pacific, with a patchy distribution.
Description
It is a rather big and strong regular sea urchin. The spines are robust and sharp, black with sometimes a blue-greenish tinge (depending on the light). They can be recognized thanks to the 5 grey sutures on the upper face, exhibiting distinctive zig-zag pattern. The oral face is clearer. The juveniles are clearer too (they can be black but also pale brown), and often show strikingly asymmetrical spines, due to their habit to use them for digging hiding holes in soft rocks.
Réunion island
Réunion (; ; ; known as before 1848) is an island in the Indian Ocean that is an overseas department and region of France. Part of the Mascarene Islands, it is located approximately east of the island of Madagascar and southwest of the is ...
(along with some '' Echinometra mathaei'').
Image:Stomopneustes variolaris plage Jacques Tessier.jpg, ''idem''
Image:Stomopneustes variolaris Réunion loges.jpg, ''Stomopneustes variolaris'' burrowing in Réunion island
They can be confused with the
Diadematidae
The Diadematidae are a family of sea urchins. Their tests are either rigid or flexible and their spines are long and hollow.
* '' Astropyga'' Gray, 1825
**'' Astropyga radiata'' ( Leske, 1778), extant
**'' Astropyga pulvinata'' (Lamarck, 1816), ...
sea urchins which sho longer and more slender spines, with an anal papilla, or with ''
Echinometra mathaei'', which also digs holes but is smaller, with shorter spines and never truly black.
Habitat and distribution
This species shows a remarkably patchy distribution though it can be pretty abundant where they are found. They can be encountered from the east African coast to the Philippines, on rock and damaged reefs, most often in shallow waters but never too close to wave action.
They are particularly abundant in Sri Lanka.
See also
*
References
Stomopneustoida
Monotypic echinoderm genera
Echinoderms described in 1816
Taxa named by Jean-Baptiste Lamarck
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