Atlantic Sea Nettle

Northern Sea Nettle

Chrysaora melanaster

DID YOU KNOW?

This jelly’s tentacles can grow to a length of 10 feet.

Exhibit Name and Location:
Baltimore - Jellies Invasion: Oceans Out of Balance

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Atlantic Sea Nettle Atlantic Sea Nettle Atlantic Sea Nettle

Northern Sea Nettle

This jelly's bell can be white to dark purple/red, with dark lines radiating from the top of the bell. The species derives its name from the Greek words melas and aster, which translates to "black star" in reference to the pattern on its bell.

Although not very venomous, their sting can cause an allergic reaction in some people. Their nematocysts (i.e., stinging cells) are powerful, capable of causing serious skin irritation and burning sensations.

Diet

Zooplankton, including small crustaceans and other jellies

Size

Bell can be up to 12 inches wide; tentacles can extend as long as 10 feet on giant specimens

Range

Pacific Ocean, from Japan north to the Bering Sea

Population Status

In the past, jelly populations were kept in check by predators like sea turtles and jelly-eating fish. Due to the reduction of these predators, jelly populations are growing at alarming rates. There are some concerns that this species is beginning to expand its range farther north, and will out-compete commercially important fish species, such as herring and juvenile salmon, for the tiny food they both consume.

Predators

Sea turtles and other jelly-eating animals such as tuna, sunfish, butterfish and spiny dogfish keep the jelly populations in balance. All seven species of sea turtles include them in their diets. The largest sea turtle species, the leatherback, depends on jellies for food. Because jellies are more than 90 percent water and an adult leatherback can weigh more than 2,000 pounds, one turtle can consume a lot of jellies.

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A Note From the Caretaker

Ninja toxin! It has been reported that the ancient ninja warriors of Japan used to scatter dried venom from this species into the wind to irritate the nose and eyes of their enemies during battle. Fortunately for our aquarists, the sting of this species is rated moderate to severe, and is only fatal to small sea creatures.