Blue glaucus

Glaucus atlanticus

Size: 2–4 cm · 0.1–3 g
Diet: Carnivore
Activity: Cathemeral
Sociality: Solitary
Lifespan: up to 1 year

The blue glaucus is a tiny nudibranch that floats near the sea surface with blue, winglike lobes. It eats stinging animals and stores their defenses in its own body.

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Key facts

Blue glaucus (Glaucus atlanticus) is a carnivore animal classified as Invertebrate · Nudibranchia · Glaucidae.
Primary habitats are open ocean · coast, with a range across Atlantic Ocean · Pacific Ocean · Indian Ocean.
Activity is cathemeral, sociality is solitary, and conservation status is LC (Least Concern).
The blue glaucus is a tiny nudibranch that floats near the sea surface with blue, winglike lobes.
It drifts in warm surface waters of the Atlantic, Pacific, and Indian oceans, both offshore and near coasts.
Typical lifespan: up to 1 year

Sources

wikidata.org

Range

Habitat range map

Native rangeOccasional / Transient

Map: Ecoregions 2017 © RESOLVE (CC BY 4.0) · Natural Earth (PD)

Details

Habitat

It drifts in warm surface waters of the Atlantic, Pacific, and Indian oceans, both offshore and near coasts. Winds and currents sometimes strand it on beaches.

Appearance

Length 2-4 cm; weight 0.1-3 g. A deep blue underside and silvery back provide countershading at the surface. Fingerlike cerata spread from the sides, giving it a starry outline.

Behavior

Cathemeral and solitary, it floats upside down by holding air in the body. Waves and surface currents carry it between patches of prey.

Feeding

A carnivore, it feeds on floating cnidarians such as Portuguese man-of-war. Stinging cells from prey are stored in the cerata and reused for defense.

Reproduction

Individuals are hermaphrodites and lay strings of eggs after mating. Eggs may be attached to floating material or prey remains, and larvae drift in the plankton.

Notes

It is listed as Least Concern, but it can still sting through stored nematocysts. Stranded animals should not be handled bare-handed.