The sea blubber jellyfish (also known as the lion mane jellyfish) can have a bell that reaches up to a meter or more in size and its tentacles can be up to 9 meters long. You can find them from Alaska to California, and they can be seen in all parts of the Pacific Northwest, they prefer inshore coastal waters.
They can be red-brown, yellow, rose, violet, or white with numerous long tentacles, you will find small fish inhabiting the underside of large bells. You must be very careful around these jellyfish as contact with the tentacles can cause severe burning and blisters that are very painful.
On the Atlantic side of Canada, there have been sightings of sea blubber jellyfish that reach up to 2.5 meters across the bell and tentacles of 20 meters.
These jellyfish are very beautiful to watch as they seem to pulsate through the tidal zones looking for a meal. The one in this video was about half a meter across, it was quite fascinating to watch it move about.
They feed on plankton, small fish, other jellyfish, and small shrimp are the staple diet of the sea blubber jellyfish. It is an opportunistic carnivore and, to catch its prey, it entangles them with the powerful stings on its netted tentacles. Large Lion’s Mane Jellyfish have few natural predators, due to their size and the abundance of stinging tentacles they possess. However, the smaller ones may be preyed upon by large fish, seabirds, and sea turtles, the Leatherback sea turtle feeds on jellyfish.
The sea blubber jellyfish can be found in the deeper coastal waters and oceans of North America. The cold waters of the Arctic, Northern Atlantic, and Northern Pacific Oceans prove ideal for them. Watching them swim is almost hypnotic.