How Big Do Jellyfish Get? (10 Biggest and 10 Smallest)

With their translucent, globular bodies and delicate-looking but sometimes deadly tentacles, it’s fair to say that jellyfish are one of the strangest creatures on earth. On top of their alien appearance, they also come in various shapes and sizes – sizes so huge, in fact, that it’s a little hard to believe!

Jellyfish can grow to be between just a millimeter and as big as 7 feet wide. The jellyfish species with the largest head or ‘bell’ is the Lion’s Mane Jellyfish in the Arctic and Northern Pacific. This species is also the world’s longest, measuring 120 feet (36.5 meters) from the top of its head to the tip of its tentacles.

If jellies weren’t fascinating enough, they also come in unexpected bodily shapes and colors. From the world’s tiniest jellyfish to those longer than a blue whale, here are the top 10 biggest (and smallest) jellyfish in the world!

Top 10 Biggest Jellyfish

1. Barrel Jellyfish

Also known as the ‘frilly-mouthed jellyfish’ the Barrel jelly can be white, brown, blue, or green and is commonly found in the warm coastal waters of Britain, but has also been spotted in the Mediterranean and South Africa. They’re typically 1.4 ft wide with 8 inch tentacles and weigh around 55 to 77 lbs.

2. Lion’s Mane

Weighing up to 200 lbs, the colossal Lion’s Mane jelly is named for its dense, hairy tentacles and lives in the Atlantic and Pacific ocean. It ranges in color from tan/orange to red or purple depending on size and the largest kind has a 7 ft wide bell with almost 120 ft-long tentacles.

3. Pink Meanie

First found off the Gulf of Mexico in 2000, the relatively new Pink Meanie jellyfish species has a 3 ft-wide bell and 70 ft-long tentacles, which are all different lengths like a sheer pink curtain. The Pink Meanie jelly can weigh up to 50 lbs.

4. Box Jellyfish

This blue Australian species is the most deadly jellyfish in the world, with 79 deaths recorded since records began. They weigh 41½ lbs; have a bell measuring 1.5 ft in diameter, and one sting from their 10 foot-long tentacles (which contain 500 stinging cells each) can cause cardiac arrest, paralysis, and even death in under 3 minutes.

5. Stygiomedusa Gigantea

This unusual jelly is also known as the ‘Phantom jellyfish’ and can be found in the Pacific Ocean and has a 3 ft-wide head but no tentacles – instead it has four flat strap-like ‘arms’ reaching 32 feet long, which it uses to grab and trap prey instead of sting them. It weighs up to 90 lbs.

6. Nomura’s Jellyfish

Weighing a colossal 440 lbs, the Nomura’s jellyfish is almost the size of an adult man, with a bell diameter and tentacles both measuring 6 ft in width and length. These are native to the Yellow Sea and the East China Sea and have golden-yellow tentacles.

7. Black Sea Nettle

This rarely-seen jelly was first discovered in 1997 and has a deep maroon color. Black Sea Nettles can be found in the Pacific swimming alongside Butterfish. These jellies have a 3 ft-wide bell and 25 ft-long tentacles, but their weight is currently unknown.

8. Tiburonia Granrojo

Also known as the ‘Big Red jellyfish’, this species is found off the coast of North America, Hawaii, and Japan and has a bell measuring 2 ft 6 inches across. Instead of tentacles, it has 4 to 7 short, stubby arms covered in stingers and it is not known how much it weighs.

9. Purple Striped Jelly

Often spotted in Monterey Bay in California, this pretty-patterned jelly has purple vertical stripes on its 2.3 ft wide bell and tentacles measuring 1 foot in length. It has an odd mix of arms and long white tentacles. Its weight is not currently known.

10. Venus’ Girdle

This astonishing rare jellyfish resembles more of a purple translucent eel than a jelly as we know it! Venus’ Girdle is a ‘comb jelly’ (an invertebrate with comb-like organelles) and is found in the Mediterranean. Its flat ribbon-like body is 1 meter long and 2 inches wide.

Top 10 Smallest Jellyfish

1. Crystal Jellyfish

The beautiful Crystal jellyfish is colorless and found off the west coast of North America. Their bell can be as small as just under 10 inches across and their 150 tentacles measure around 8 inches long.

2. Moon Jellyfish

At their smallest size, Moon jellyfish are only 5cm wide or the size of a small dinner plate at their largest. They have purple, translucent bodies and reside along the coast of Atlantic North America and Europe. The biggest moon jellies weigh just over 3 grams!

3. Malo Bella

Malo Bella jellyfish belong to the Irukandji (mini box jellyfish) species and measure no more than a 2 cent piece and weigh considerably less! This miniature jelly can be found in the tropical waters of Western Australia.

4. Bloodybelly Comb Jellyfish

This comb jellyfish has a very odd appearance – it has tiny hair-like projections instead of tentacles which help push its irregular-shaped crimson body through the water. Bloodybelly jellies reside in the depths of the Pacific and are only 6 inches long.

5. Jelly Blubber

Found in Queensland and New South Wales, Jelly Blubbers have a creamy-white or bright blue color and are between 4 to 13 inches wide. This species has 8 short, feathery tentacles and will change color depending on the waters they’re in.

6. White-spotted Jellyfish

This pretty species has a bell dome measuring 15 inches across and they can be found in the Gulf of California and Mexico and around the Hawaiian islands. White-spotted jellies weigh up to 25 lbs and are considered invasive due to their huge appetite.

7. Flower Hat Jelly

This quirky-looking jellyfish species has a clear pinstriped bell measuring 6 inches across and has many short and multi-colored feeding tentacles that look like mini flower buds. They’re found in the coastal waters of Brazil, Japan, and Argentina.

8. Atolla Jellyfish

Atolla jellyfish resemble an alien spaceship with tentacles attached! Their tentacles range from 1.5 inches to 1 ft long and their bell measures 6 inches across. Atollas are found all over the world in the ocean depths, where their bodies flash red like a warning siren.

9. Bluebottle Jellyfish

These fairly small blue jellies are often found on the eastern coast of Australia and measure between 0.7 and 6 inches in bell size. They have a clear, blue-tinged body with a stegosaurus-like shape and have long tentacles stretching to 160 feet!

10. Immortal Jellyfish

The incredible Immortal Jellyfish measure just 4.5mm across (no bigger than a pink fingernail) and they can actually revert back to a younger state indefinitely! They have a bright center in their transparent bell, have up to 90 tentacles. They’re found in the Caribbean Sea.