Diadema setosum

About this species

Diadema setosum is a species of long-spined sea urchin belonging to the family Diadematidae. It is a typical sea urchin, with extremely long, hollow spines that are mildly venomous. D. setosum differs from other Diadema with five, characteristic white dots that can be found on its body. The species can be found throughout the Indo-Pacific region, from Australia and Africa to Japan and the Red Sea. Despite being capable of causing painful stings when stepped upon, the urchin is only slightly venomous and does not pose a serious threat to humans.

Text from the Wikipedia article “Diadema setosum”, licensed CC BY-SA 4.0. Read the article

Where and when

Where it has been recorded

Worldwide

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Best months

Worldwide (open data)

January: 178 records
February: 179 records
March: 234 records
April: 320 records
May: 347 records
June: 306 records
July: 468 records
August: 373 records
September: 362 records
October: 280 records
November: 239 records
December: 202 records

Depth and water temperature

Depth

Mostly recorded at 2–27 m · Deepest record: 428 m

0–10 m: 58 records
10–20 m: 25 records
20–30 m: 2 records
30–40 m: 0 records
40–50 m: 0 records
50–60 m: 8 records
60–70 m: 0 records
70–80 m: 0 records
80–90 m: 0 records
90–100 m: 0 records
100–110 m: 0 records
110+ m: 1 records

Water temperature

Recorded in surface water of 21–30 °C

20–22 °C: 2 records
22–24 °C: 32 records
24–26 °C: 23 records
26–28 °C: 23 records
28–30 °C: 39 records

Photos

(c) portioid, some rights reserved (CC BY) · CC BY · iNaturalist
(c) Matt Muir, some rights reserved (CC BY) · CC BY · iNaturalist
(c) Ewout Knoester, some rights reserved (CC BY-SA) · CC BY-SA · iNaturalist
(c) Kane Sandoval, some rights reserved (CC BY) · CC BY · iNaturalist
(c) nebrooks, some rights reserved (CC BY) · CC BY · iNaturalist
(c) luluchouette, some rights reserved (CC BY) · CC BY · iNaturalist
(c) Debra Baker, some rights reserved (CC BY) · CC BY · iNaturalist

Names and classification

Names in 1 more languages

Japanese: ガンガゼ

Other scientific names: Calmarius annellata, Centrechinus (Diadema) setosus, Centrechinus setosus, Centrostephanus setosum, Centrostephanus setosus, Cidaris (Diadema) tenuispina, Cidarites diadema, Diadema lamarcki, Diadema nudum, Diadema saxatile, Diadema setosa, Diadema turcarum, Echinometra setosa, Echinus saxatilis, Echinus ſaxatilis

Similar species

Savigny's Longspine Sea Urchin
Diadema savignyi
Blue-spotted Urchin
Astropyga radiata
Banded sea urchin
Echinothrix calamaris
Blue-black urchin
Echinothrix diadema
Chaetodiadema granulatum
Eremopyga debilis

Sources and credits

Names and taxonomy: WoRMS (CC BY 4.0) and the GBIF Backbone (CC BY 4.0). Photos: iNaturalist observers, each under the licence shown (CC0, CC BY or CC BY-SA).

Depth, temperature, months and maps: records from OBIS and GBIF under CC0 or CC BY.
Descriptions: Wikipedia, licensed CC BY-SA, each linked to its article.
Conservation status as published by GBIF (IUCN Red List).
2,733 open-data records from 1758 to 2022.
Species data updated October 26, 2026.