What is the world's largest species of jellyfish?

The world's largest species of jellyfish is the lion's mane jellyfish (Cyanea capillata). It can have a bell diameter of up to 7 feet (2.1 meters) and tentacles that can stretch up to 120 feet (36.6 meters) long.

These massive creatures are found in the northern hemisphere, including the Arctic and northern Atlantic oceans, and can be recognized by their red, yellow, or brownish bell with long, slender tentacles. Their diet mainly consists of small fish, zooplankton, and other jellyfish.

While the lion's mane jellyfish is the largest species, it is not the most venomous. Its sting can be painful but is not usually life-threatening, unless an individual has an allergic reaction. It is still important to give them a wide berth if you see one in the water.