Invertebrates
Cannonball Jellyfish
Stomolophus meleagris · also called cabbagehead jellyfish
A leatherback sea turtle glides through a swarm of cannonball jellyfish, snapping up one smooth, round bell after another, entirely unbothered by a sting so mild it barely registers against the turtle’s own tough mouth and throat.
Overview
The cannonball jellyfish, Stomolophus meleagris, is a smooth, round-belled jellyfish native to coastal waters along the Atlantic and Gulf coasts of North America. Its unusually mild sting, short stubby oral arms, and significant role both as commercial harvest and leatherback turtle prey make it one of the more economically and ecologically important jellyfish species in its range.
A jellyfish valued from two very different directions
Few animals end up simultaneously important to a commercial seafood industry and to the survival of an endangered sea turtle, but the cannonball jellyfish fills both roles at once, valued by people and predators for entirely different reasons.
Status
Least Concern — widespread and abundant across suitable coastal habitat along the Atlantic and Gulf coasts, despite substantial commercial harvest.
Cannonball Jellyfish: common questions
Is the cannonball jellyfish dangerous to swimmers?
Not especially — the cannonball jellyfish delivers a comparatively mild sting, generally far less painful than the sting of many other common jellyfish species, making it one of the less concerning jellyfish for swimmers to encounter even though contact can still cause some mild irritation.
Why is the cannonball jellyfish harvested commercially?
Cannonball jellyfish are harvested commercially in substantial quantities, particularly for export to food markets in parts of Asia where jellyfish is a traditional ingredient, and the species is also researched for potential uses in collagen-based products given the composition of its body tissue.
What eats the cannonball jellyfish?
The cannonball jellyfish serves as an important food source for leatherback sea turtles, which rely heavily on jellyfish as a major part of their diet, making the abundance of cannonball jellyfish populations directly relevant to the health of leatherback foraging areas.
How is the cannonball jellyfish different from jellyfish with long tentacles?
A cannonball jellyfish has short, stubby oral arms rather than the long trailing tentacles found on many other jellyfish species, paired with a smooth, round, dome-shaped bell, a body plan that gives it both its common name and its comparatively mild sting.