Red rock worm

Marphysa sanguinea

Other invertebrates
IUCN: Not evaluated

Usual depth0–35 m
Water temperature10–29 °C
Best monthsJune, July, and August
How commonOccasional

All species

Where and when

Where it has been recorded

Worldwide

Loading the map

Best months

Worldwide (open data)

January: 24 records
February: 66 records
March: 91 records
April: 120 records
May: 100 records
June: 223 records
July: 157 records
August: 168 records
September: 115 records
October: 49 records
November: 33 records
December: 15 records

Depth and water temperature

Depth

Mostly recorded at 0–35 m · Deepest record: 500 m

0–10 m: 456 records
10–20 m: 170 records
20–30 m: 93 records
30–40 m: 73 records
40–50 m: 24 records
50–60 m: 12 records
60–70 m: 5 records
70–80 m: 2 records
80–90 m: 0 records
90–100 m: 0 records
100–110 m: 2 records
110+ m: 10 records

Water temperature

Recorded in surface water of 10–29 °C

8–10 °C: 4 records
10–12 °C: 25 records
12–14 °C: 459 records
14–16 °C: 22 records
16–18 °C: 52 records
18–20 °C: 38 records
20–22 °C: 4 records
22–24 °C: 29 records
24–26 °C: 48 records
26–28 °C: 15 records
28–30 °C: 8 records

Names and classification

English: Red rock worm, Red-gilled marphysa, Rock worm, red-gilled marphysa, red rock worm, rock worm

Names in 2 more languages

German: Blutkieferwurm
Japanese: イワムシ

Other scientific names: Eunice sanguinea, Leodice opalina, Marphysa iwamushi, Marphysa iwamusi, Nereis sanguinea

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).
1,536 open-data records from 1813 to 2023.
Species data updated November 4, 2026.

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