Location: Maui, Hawaii
Florent's Guide To The Hawaiian, South Pacific and
Indo-Pacific Reefs
Blue-Black Urchin
Echinothrix diadema
Blue-Black Urchin
Category: Sea Urchins
Scientific Name: Echinothrix diadema
Size: 4 to 8 in. (10 to 20 cm)
Depth: 3-30 ft. (1-10 m)
Distribution: Indo-Pacific, Hawaii
Echinodermata (Phylum)
└Echinozoa (Subphylum)
└Echinoidea (Class)
└Euechinoidea (Subclass)
└Diadematoida (Order)
└Diadematidae (Family)
└Echinothrix (Genus)
└E. diadema (Species)
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© 2026 Florent Charpin