One-horned Spider Crab

Menaethius monoceros

Crustaceans
IUCN: Not evaluated

Usual depth1–58 m
Water temperature16–30 °C
Best monthsMay and December
How commonOccasional

All species

Photo credit: (c) Srichakra Pranav Tamarapalli, some rights reserved (CC BY-SA) · CC BY-SA · iNaturalist

Where and when

Where it has been recorded

Worldwide

Loading the map

Best months

Worldwide (open data)

January: 17 records
February: 12 records
March: 24 records
April: 24 records
May: 64 records
June: 22 records
July: 19 records
August: 26 records
September: 8 records
October: 19 records
November: 11 records
December: 50 records

Depth and water temperature

Depth

Mostly recorded at 1–58 m · Deepest record: 58 m

0–10 m: 3 records
10–20 m: 0 records
20–30 m: 1 records
30–40 m: 0 records
40–50 m: 0 records
50–60 m: 1 records

Water temperature

Recorded in surface water of 16–30 °C

14–16 °C: 1 records
16–18 °C: 0 records
18–20 °C: 6 records
20–22 °C: 63 records
22–24 °C: 14 records
24–26 °C: 48 records
26–28 °C: 42 records
28–30 °C: 57 records

Photos

(c) Cricket Raspet, some rights reserved (CC BY) · CC BY · iNaturalist
(c) Srichakra Pranav Tamarapalli, some rights reserved (CC BY-SA) · CC BY-SA · iNaturalist
no rights reserved · CC0 1.0 · iNaturalist
(c) Daniel Eisenhauer, some rights reserved (CC BY) · CC BY · iNaturalist
(c) 呂一起(Lyu yi-chi), some rights reserved (CC BY) · CC BY · iNaturalist
(c) Jay Paroline, some rights reserved (CC BY) · CC BY · iNaturalist
(c) Daniel Eisenhauer, some rights reserved (CC BY) · CC BY · iNaturalist

Names and classification

English: One-horned Spider Crab

Names in 2 more languages

Japanese: イッカクガニ
Simplified Chinese: 單刺單角蟹

Other scientific names: Inachus arabicus, Menaethiops monoceros, Menaethius angustus, Menaethius areolatus, Menaethius dentatus, Menaethius depressus, Menaethius inornatus, Menaethius porcellus, Menaethius rugosus, Menaethius subserratus, Menaethius tuberculatus, Pisa monoceros

Similar species

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.
Conservation status as published by GBIF (IUCN Red List).
592 open-data records from 1825 to 2023.
Species data updated November 4, 2026.

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