[2] These sea slugs live in the pelagic zone (open ocean), where they float upside-down by using the surface tension of the water to stay afloat.

[11][12][13] The radula of this species bears serrated teeth,[14] which paired with a strong jaw and denticles, allows it to grasp and "chip down" parts of its prey.

[3] Observations in 2015 and 2016 suggested that the G. atlanticus species' geographical range had increased northward by 150 km in the Gulf of California compared with previous sightings.

This is in line with the known habitat characteristics of the species; they thrive in warm, temperate climates in the Southern Pacific, and in circumtropical and Lusitanian environments.

Before finding G. atlanticus off Andhra Pradesh, these nudibranchs were documented as having been seen in the Bay of Bengal and off the coast of Tamil Nadu, India, over 677 km apart.

[17] G. atlanticus was also recently found off Bermuda in January 2016,[18] and uncommonly washes ashore on east coast beaches at Barbados, Lesser Antilles.

The sea slugs can move toward prey or mates by using their cerata, the thin feather-like "fingers" on its body, to make slow swimming movements.

[24] Like almost all heterobranchs, blue dragons are hermaphrodites and their male reproductive organs have evolved to be especially large and hooked to avoid their partner's venomous cerata.

Gene flow among Afro-Eurasian and American populations is thus hindered by physical obstructions and water temperatures in the Arctic and Southern Oceans.

[26] The symptoms that may appear after being stung are nausea, pain, vomiting, acute allergic contact dermatitis, erythema, urticarial papules, potential vesicle formation and postinflammatory hyperpigmentation.

[13] In 2023, Julian Obayd, a TikTok user whose videos focus on marine life, went viral after going to the hospital for several Blue Dragon stings.