Glaucilla marginata
- Usual depth0 m
- Water temperature20–27 °C
- Best monthsDecember
- How commonRare
Photo credit: (c) Glaucus_atlanticus_1.jpg, some rights reserved (CC BY) · CC BY · iNaturalist
About this species
Glaucus marginatus is a species of small, floating, blue sea slug; a pelagic (open-ocean) aeolid nudibranch; a marine opisthobranch gastropod mollusc in the family Glaucidae. This species is closely related to Glaucus atlanticus, and is part of a species complex along with Glaucus bennettae, Glaucus thompsoni, and Glaucus mcfarlanei. Like Glaucus atlanticus, it is commonly known as a blue dragon.
Text from the Wikipedia article “Glaucus marginatus”, 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: 4 records
- February: 7 records
- March: 5 records
- April: 8 records
- May: 5 records
- June: 3 records
- July: 3 records
- August: 4 records
- September: 5 records
- October: 2 records
- November: 5 records
- December: 17 records
Depth and water temperature
Depth
Mostly recorded at 0 m · Deepest record: 0 m
Water temperature
Recorded in surface water of 20–27 °C
Photos
(c) Srichakra Pranav Tamarapalli, some rights reserved (CC BY-SA) · CC BY-SA · iNaturalist
Names and classification
Other scientific names: Glaucilla briareus, Glaucus marginatus
Similar species
Atlantic Sea SwallowGlaucus atlanticus
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.
- 29 open-data records from 1976 to 2025.
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