Echinoidea (sea urchins)
- Black Sea Urchin (Echinothrix diadema)
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WARNING: has venomous spines - do not attempt to touch or handle this urchin species
Distribution:
Indo-Pacific, including the Eastern Pacific
Habitat :
In holes on the reef; depths of about 21 m
Max. size :
up to 15 cm diameter
Behavior and biology :
large urchins with long, slender, needle-like black spines; primary spines are shorter than the test diameter and banded light and dark green in young specimens; they have two distinct sizes of spines.
Gametes from males and females are simultaneously released into the water column, where fertilization takes place. The larvae may persist in the ocean for weeks to months, allowing for geographically wide dispersal.
It tends to live under ledges or in depressions, hiding in crevices or under rocks during the day. At night they are also active, coming out to graze on algae
- Rock-boring urchin (Echinometra mathaei)
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Indo-Pacific
Indo-Pacific
Habitat :
Rocks
Max. size :
5 cm
Behavior and biology :
Colour in life highly variable, spine mostly brown and greenish brown, tip of spines not white, basal ring of spine unclear. This specie has extensive morphological variations in the shape, spine colour design and ecological distribution.Urchins graze on sandstone and at the same time, they also produce sediments by discharging various intakes into the sea bottom of the coral reefs.
