A flower hat jelly can coil its colorful tentacles close to its bell, then extend them to capture prey. The result looks floral, but the animal is a hunter.
Often called Olindias formosus and also listed as Olindias formosa in older aquarium sources, it belongs to the hydrozoans.
A jelly with a different family tree
The Monterey Bay Aquarium flower-hat-jelly account distinguishes it from the group commonly called true jellyfish.
Both are cnidarians, but that shared relationship does not make them members of the same class. Common names can hide those differences.
Its patterned bell and bright tentacle tips make it especially memorable in aquarium displays.
A hunter near the bottom
Flower hat jellies can rest near the seabed rather than spend all their time drifting through open water.
Their tentacles capture prey, including small fishes. Stinging cells help secure food.
Beauty should not be mistaken for an invitation to touch. Watching the tentacles from a distance is enough to appreciate their detail.
What aquarium lighting changes
Several photographs here were taken under aquarium illumination, including blacklight. The lighting can strongly affect the colors a camera records.
A brightly illuminated aquarium scene therefore looks different from a jelly resting in coastal water. Color alone does not tell us whether an animal is producing its own light.
Let curiosity reach beyond color
The flower hat jelly is associated with coastal waters, including Japan. Its feeding habits and resting behavior are as interesting as its appearance.
A colorful portrait starts the story. Understanding the animal behind it reveals something richer: a small coastal predator with a very different way of meeting the world.
Photo credits
Featured image: Flower Hat Jelly Aquarium of the Pacific 2015.jpg — Patrick Pelletier; CC BY-SA 4.0.
Body image 1: Flower hat jelly.jpg — Dennis Mojado; CC BY 2.0.
Body image 2: Olindias formosus at Monterey Bay Aquarium.jpg — Bill Abbott; CC BY-SA 2.0.
Images supplied at web display size where available.