A Journey With the By-The-Wind Sailor

Introducing the coolest relative of a jellyfish, the By-the-wind Sailor (Velella velella). The deep blue body of the creature rests on the top of the ocean with its tentacles hanging down below to catch its plankton prey. On top is the Sailor’s characteristic stiff sail which behaves much the way a sail of the ship does!

Each Velella is a hydroid colony, and most are less than about 7 cm long. What exactly is a hyroid colony you ask? Well, simply put it is a colony of tiny predatory creatures called polyps that feed on ocean plankton and are connected by a canal system that enables the colony to share whatever food is ingested by individual polyps with the rest of the group.

Like many Hydrozoa, Velella velella has a bipartite life cycle, with a sort of alternation of generations. Read up on the wikipedia article here for a more detailed description if you’d like!

It is lucky that the By-the-wind Sailor is equipped with its own personal sail. However, having no means of locomotion, V. velella are at the mercy of prevailing winds for moving around the seas, and are thereby also subject to mass-strandings on beaches throughout the world. Offshore boaters are sometimes treated to seeing thousands of V. velella at a time on the water surface.

Creatures that live partly in and partly out of the water like this are known as “pleuston.”

Hope you enjoyed this interesting species! 🙂