Invertebrates
Stalked Jellyfish
Stauromedusae · also called stauromedusae
Anchored to seaweed or rock by a stalk for its entire adult life, a stalked jellyfish never drifts freely through open water the way most jellyfish do, instead trapping passing prey with a ring of branching, tentacle-tipped arms around its trumpet-shaped body.
Overview
The stalked jellyfish, order Stauromedusae, is a sessile cnidarian native to coastal ocean habitat recorded across temperate and polar waters worldwide. Its lifelong attachment to a fixed surface, distinctive trumpet-shaped body, and skipped free-swimming life stage make it one of the more unusual members of the jellyfish group found anywhere along cold and temperate coastlines.
A jellyfish that never learned to swim
While the free-swimming bell is the defining image most people associate with jellyfish, the stalked jellyfish never develops one at all, spending its entire life anchored in place and relying on passing currents to bring food within reach of its waiting tentacles.
Status
Not Evaluated, though some species are considered locally uncommon due to habitat loss affecting the seaweed and eelgrass beds they depend on.
Stalked Jellyfish: common questions
Does the stalked jellyfish ever swim freely like other jellyfish?
No, this order spends its entire adult life attached to seaweed, rock, or other hard surfaces by a stalk, unlike most true jellyfish, which drift freely through open water during at least part of their life cycle.
Can a stalked jellyfish move at all?
To a limited degree, this order can detach from its surface and slowly somersault or crawl to a new location, an unusual form of limited mobility for an animal that otherwise remains fixed in place.
How is the stalked jellyfish's life cycle different from other jellyfish?
This order skips the free-swimming medusa stage found in the life cycle of most true jellyfish, remaining in a stalked, attached form throughout its entire adult life rather than transforming into a drifting bell shape.
Where is the stalked jellyfish usually found?
This order is most commonly found in cold and temperate coastal waters, often attached to eelgrass, kelp, or rocky surfaces in shallow water rather than in the open ocean.