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.[1][2] This species is closely related to Glaucus atlanticus, and is part of a species complex (Informal clade Marginatus) along with Glaucus bennettae, Glaucus thompsoni, and Glaucus mcfarlanei.[3] Like Glaucus atlanticus, it is commonly known as a blue dragon.[4]
Glaucus marginatus | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Gastropoda |
Subclass: | Heterobranchia |
Order: | Nudibranchia |
Suborder: | Cladobranchia |
Family: | Glaucidae |
Genus: | Glaucus |
Species: | G. marginatus
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Binomial name | |
Glaucus marginatus | |
Synonyms[1] | |
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This nudibranch is dark blue, and in many ways it resembles a smaller version of Glaucus atlanticus. However, in this species the cerata are arranged in a single row in each arch.[citation needed]
While G. atlanticus is up to 3 centimetres (1.2 in) long, G. marginate is only about 1.3 centimetres (0.51 in) long, and its tail is shorter than its cousin. The species has a light and dark blue foot.[4]
This species is pelagic, and can be found in the Pacific Ocean.[citation needed]
While they do not usually inhabit coastal regions, hundreds of the creatures were observed washing up on one of the Sydney North Shore beaches, near Long Reef, in February 2021.[4]
These small nudibranches float upside down on the surface tension in temperate and tropical seas. They eat colonial cnidarians such as the Portuguese man o' war[2] (a.k.a. bluebottle, or Physalia utriculus), blue buttons (Porpita porpita), and the by-the-wind sailor (Velella velella).[4]