Praya dubia zooids arrange themselves in a long stalk—usually whitish and transparent (though other colours have been seen)—known as a
physonect colony. Next to it are the nectophores, powerful
medusae which pulsate in rhythmic coordination which propel
Praya dubia through ocean waters. Together, the array is known as the
nectosome. Beneath the nectosome is the
siphosome which extends to the far end of
Praya dubia, containing several types of specialized zooids in repeating patterns. Transparent bracts (also called
hydrophyllia), are leaf-shaped organs generally thought to be another type of zooid which covers and forces other zooids to contract in times of danger. Pneumatophores, which have gas to provide flotability, next are the nectophores, these structures that, by expelling water to propel the colony, are little motors. Gastrozooids, which are the mouth and stomach of the colony, and Dactylozooids, which are like tentacles equipped for defense and hunting with stinging cells. Due to their
hydrostatic skeleton being held together by water pressure above , these animals burst when brought to the surface. The remains of
Praya dubia dredged up in fishing nets resemble a blob of gelatin, which prevented their identification as a unique creature until the 19th century. In 1987,
Monterey Bay Aquarium Research Institute observed living
Praya dubia during a systematic study of a
water column, the animal's natural
habitat, in
Monterey Bay. == Behavior ==