Like sea stars, sea cucumbers and brittle stars, sea urchins are part of the Echinoderms phylum. With their spherical body covered moveable spines, they are among the most iconic inhabitants of the sea.
More than 900 species of sea urchins (or Echinoidea) inhabit the world’s seas and oceans, with variable coloration and shape. They are easily found when snorkeling, moving slowly on the bottom using their tube feet.
Swimmers are often afraid of being stung by sea urchins, which can cause serious injuries when not treated.
Some tropical urchin species are also poisonous, like the fire urchins, collecting urchins, and the flower urchin, whose venom can cause serious reactions. Learn to identify it: its tube feet often cover its entire body, masking its spines.
Sea urchins are seen almost everywhere in snorkeling, including in tidal pools and at very shallow depths.
The red pencil urchin, with very thick and rounded spines, is very photogenic. It is found throughout the Indo-Pacific, where it is very common, especially on the reefs of Hawaii.
Long-spined sea urchin, with their very small body (or “test”) and their very long spines (which can reach almost 30cm) are easy to identify. There are 3 species of long-spined sea urchin distributed in the different tropical seas.
Collector sea urchins (genus Tripneustes) have the ability to cover themselves with coral or algae fragments to better hide. In the Mediterranean, purple and black sea urchins are easy to see in rocky areas.
Caribbean slate pencil urchin
Caribbean white sea urchin
Long spined urchin
Rock boring urchin
Inflated sea biscuit
Red pencil urchin
Double spined urchin
Indo-Pacific long-spined sea urchin
Stained collector urchin
Red Sea collector urchin
Tripneustes gratilla elatensis
Slate pencil urchin
Eastern Pacific white sea urchin
Galápagos green sea urchin
Needle sea urchin
Central American rock boring urchin
Rose flower urchin
Black sea urchin
Purple sea urchin
Violet sea urchin
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