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Glowing blue midwater jellyfish with long trailing tentacles against black background

Midwater jelly

Colobonema sericeum

Not on exhibit
Animal type
Invertebrates
Ecosystem
Deep sea
Relatives
Other hydromedusae; Family: Rhopalonematidae
Diet
Small crustaceans
Range
Midwater (2,297–3,281 feet, or 700–1,000 m)
Size
Up to 1 inch (2.5 cm) in diameter

Meet the midwater jelly

Colobonema is found in many regions of the world. Compared to a lot of jellies, it's a strong swimmer. It's equipped with 32 tentacles. When disturbed, its tentacles can drop off, confusing a would-be predator. Scientists suspect that Colobonema can re-grow the dropped tentacles, since they often observe this jelly with tentacles of different lengths.

Conservation

Anything that finds its way into the ocean—whether it's tossed away as trash or washed off a beach or boat—may eventually make its way to the deep sea. It's important to realize that the deep sea is not so far away that it's beyond the reach of human activities. Living creatures in the deep are affected by what we do at the surface.

Cool facts

  • Colobonema is a carnivorous ambush predator that drifts motionless with its tentacles outspread, waiting for unsuspecting prey.

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