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echinoids
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| Phylum Echinodermata > Class Echinodea > sea urchins |
| Long-spined
black sea urchin Diadema sp. Family Diadematidae updated Aug 10 Where seen? This large, very scary-looking sea urchin is among our most commonly encountered sea urchins in deeper waters. It is said to be found in large groups where there is a lot of dead coral. It is believed that these gather together in groups where there are insufficient hiding places from daytime predators. It is also sometimes encountered on the intertidal on our Northern and Southern shores, usually alone, wedged in coral rubble or near large boulders. On Cyrene Reef, they may also be found among seagrasses. Features: Body diameter 8-10cm. It has very long primary spines, up to 30cm long, with many shorter spines in between. The spines on the underside are much shorter. The urchin can rapidly point its long spines against any potential threat (which is quite a scary thing to observe). The spines may be all black, banded black-and-white or even all white. There is bulbous sac in the middle of the upperside. This is the anal cone. There is often an orange ring around this anal cone. In some, five bright white spots can be seen on the black body, with small bright blue dots forming V-shape lines from the white spots. The underside may be pale, dark or maroon or pink.
What does it eat? It feeds on seaweed, grazing these from dead corals or rubble areas. It may also trap tiny suspended food particles with its long spines, transferring these to the mouth with tube feet. Prickly home: The sea urchin is sometimes home to other animals such as cardinalfish (Family Apogonidae), razorfishes (Family Centriscidae) and shrimps (Saron marmoratus) and anemones (Coeloplana sp.). Small white parasitic snails are also said to be associated with it. Human uses: In some places, the roe of this sea urchin is eaten resulting in heavy harversting. May be confused with the Black sea urchin (Temnopleurus sp.) with much shorter spines is more commonly seen on our Northern shores, sometimes in large numbers. |
 Cyrene Reef, Jun 08  Bulbous anal sac, five white spots and blue dots in V-shape lines.  Sideview with shorter spines on the underside and longer spines on the upperside. |
 Underside may be dark, maroon or pale. |
 Short flat spines around the mouth. |
 Spines may be black, banded or even white. |
 Close-up of mouth on underside Beting Bronok, Jul 05 |
 Close-up of spine attachment to the body Pulau Hantu, Aug 04 |
 With white spines. Pulau Hantu, Jun 08 |
Common long-spined black sea urchins on Singapore shores
 Cyrene Reef, May 08 |
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 Underside. |
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 Cyrene Reef, Aug 11 |
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more photos of long-spined black sea urchins on Singapore shores
northern shores
southern shores part 1 | part 2 | part 3 | part 4
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