Portunus segnis
- Usual depth3.5 m
- Water temperature25–29 °C
- Best monthsApril, August, and October
- How commonRare
Photo credit: (c) Dr. Nasser Halaweh, some rights reserved (CC BY), uploaded by Dr. Nasser Halaweh · CC BY · iNaturalist
About this species
Portunus segnis, the African blue swimming crab, is a species of crustacean, a swimming crab belonging to the family Portunidae. While native to the western Indian Ocean, it is also invasive in the Mediterranean. It is thought to have come through the Suez Canal from the Red Sea but it may have been transported by ships.
Text from the Wikipedia article “Portunus segnis”, 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: 10 records
- February: 7 records
- March: 7 records
- April: 19 records
- May: 15 records
- June: 14 records
- July: 16 records
- August: 19 records
- September: 16 records
- October: 26 records
- November: 18 records
- December: 17 records
Depth and water temperature
Depth
Mostly recorded at 3.5 m · Deepest record: 3.5 m
Water temperature
Recorded in surface water of 25–29 °C
Photos
(c) Ben Jobson, some rights reserved (CC BY) · CC BY · iNaturalist 
no rights reserved · CC0 1.0 · iNaturalist 
(c) Shaunak Modi, some rights reserved (CC BY) · CC BY · iNaturalist 
(c) Felicia Seichter, some rights reserved (CC BY) · CC BY · iNaturalist 
no rights reserved · CC0 1.0 · iNaturalist 
no rights reserved · CC0 1.0 · iNaturalist 
(c) Julien Renoult, some rights reserved (CC BY) · CC BY · iNaturalist
Names and classification
Other scientific names: Cancer segnis, Portunus (Portunus) mauricianus, Portunus (Portunus) segnis, Portunus mauritianus
Similar species
Blue swimming crabPortunus pelagicus
Blood-spotted swimming crabPortunus sanguinolentus
Gazami crabPortunus trituberculatus
- hairy swimming crab
Portunus pubescens
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).
- 176 open-data records from 2017 to 2022.
- Species data updated November 6, 2026.
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