It is a colony made up of numerous small connected individuals, each with a specific function, such as feeding, attack and defense. Its body is whitish and transparent. Praya dubia attracts its prey by blue bioluminescent light. The sting may cause paralysis or death.
When raised to the surface these animals burst, as they have a hydrostatic skeleton that normally experiences an average pressure of above 0.47 tons/cm2 (460 bars). Praya dubia has been known since the nineteenth century, but its length was discovered by the Monterey Bay Aquarium Research Institute.