Fire Urchin

About this species

Asthenosoma varium is a sea urchin. Growing up to 25 cm (10 in) in diameter, it lives on sand and rubble sea bottoms in the Indo-Pacific, from the Red Sea to Australia and Southern Japan. Its venom tipped spines, with distinctive globular swellings below the tip, can inflict a painful sting if handled; this pain lasts as long as several hours. This capacity, perhaps coupled with its reddish-brown colour, has given it the common name fire urchin; other commonly used names are Pacific fire urchin, elusive sea urchin, variable fire urchin, and electric sea urchin.

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

Where and when

Where it has been recorded

Worldwide

Loading the map

Best months

Worldwide (open data)

January: 19 records
February: 42 records
March: 27 records
April: 39 records
May: 33 records
June: 19 records
July: 17 records
August: 24 records
September: 19 records
October: 24 records
November: 33 records
December: 22 records

Depth and water temperature

Depth

Mostly recorded at 18–107 m · Deepest record: 243.5 m

0–10 m: 3 records
10–20 m: 3 records
20–30 m: 1 records
30–40 m: 27 records
40–50 m: 5 records
50–60 m: 5 records
60–70 m: 3 records
70–80 m: 1 records
80–90 m: 0 records
90–100 m: 0 records
100–110 m: 3 records
110+ m: 5 records

Water temperature

Recorded in surface water of 21–30 °C

20–22 °C: 1 records
22–24 °C: 0 records
24–26 °C: 19 records
26–28 °C: 1 records
28–30 °C: 40 records

Photos

(c) Georgina Jones, some rights reserved (CC BY-SA) · CC BY-SA · iNaturalist
(c) Armin G. Fabritzek, some rights reserved (CC BY) · CC BY · iNaturalist
(c) Pierre Pericard, some rights reserved (CC BY) · CC BY · iNaturalist
(c) Pauline Walsh Jacobson, some rights reserved (CC BY) · CC BY · iNaturalist
(c) Gregor Bailar, some rights reserved (CC BY) · CC BY · iNaturalist
(c) Gregor Bailar, some rights reserved (CC BY) · CC BY · iNaturalist
(c) Bernie Wong, some rights reserved (CC BY) · CC BY · iNaturalist

Names and classification

English: Fire Urchin

Names in 1 more languages

French: Oursin de feu du Pacifique, Oursin de feu, Oursin-cuir venimeux

Other scientific names: Asthenosoma grubei, Asthenosoma heteractis, Asthenosoma urens, Cyanosoma urens

Similar species

Magnificent Fire Urchin
Asthenosoma ijimai
Araeosoma tessellatum
Hygrosoma hoplacantha
Hygrosoma luculentum

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).
99 open-data records from 1908 to 2018.
Species data updated October 26, 2026.