The Largest Invertebrates in the World

Ever wonder what the largest invertebrates in the world are? Well, if you haven’t, then I’d say it’s time you begun!

The Largest Insect

This one is hard, because some insects are heavier, but shorter than others. The longest insect today is the giant stick insect of Southeast Asia, the longest of which was nearly 22 inches. The most massive insect is the South American longhorn beetle, the largest of which was 6.5 inches long. The heaviest insect was a pregnant giant weta of New Zealand, weighing in at almost two ounces.

The Largest Spider

The largest spider in the world is the goliath birdeater tarantula of South America. This inhabitant of the rain forest can grow up to a foot in length and sport inch-long fangs. Though it is harmless to humans, it can kill mice and birds for food.

The Largest Centipede

The title of largest centipede belongs to the Amazonian giant centipede, which can reach lengths of twelve inches. It is known to hunt bats as well as mice.

The Largest Millipede

The African giant black millipede is the largest in the world, reaching a length of up to eleven inches. The oldest known land-dwelling organism was a centimeter-long millipede.

The Largest Scorpion

The largest scorpion in the world is the emperor scorpion of West Africa, reaching a length of nearly eight inches. Despite its size, it is not highly venomous.

The Largest Slug

Europe boasts the largest slugs in the world. The Limax cinereoniger slug can reach a length of twelve inches. This slug is gray in color and lives in wet, cool environments such as under rotted logs.

The Largest Snail

The largest land-dwelling snail is the giant African snail, reaching lengths of up to twelve inches. The largest aquatic snail is the Syrinx aruanus, which can grow up to a meter in length and weigh in at a whopping forty pounds!

The Largest Clam

The giant clam, which inhabits the Great Barrier Reef, can reach enormous proportions. The largest are nearly five feet across and weigh four hundred pounds.

The Largest Squid

The giant squid used to be the largest known squid in the world, although it has since been outclassed. The colossal squid of Antarctica can grow even longer than the eighteen-meter long giant squid.

The Largest Jellyfish

Japan plays host to the largest jellyfish in the world, the giant Nomura. These titanic invertebrates can reach six-and-a-half feet wide and can weigh up to 450 pounds!

The Largest Earthworm

The largest earthworm puts any nightcrawler you’ve seen to shame. Earthworms of South African can grow to be twenty-two feet long. Try fishing with that.

The Largest Tapeworm

The beef tapeworm, one that has been known to live inside the small intestines of human beings can reach a staggering length of forty feet.

The Largest Sea Urchin

The Red Sea is the den for the largest sea urchin in the world. The Red Sea urchin can have a test (exoskeleton) as wide as seven inches in diameter.

The Largest Starfish

Midgardia xandros of the Gulf of Mexico has the longest arm reach of any living starfish, up to 4.5 feet. The Thromidia catalai of New Caledonia is the heaviest at nearly thirteen pounds.

The Largest Crab

The largest crab in the world is the Japanese spider crab. Though its body only measures about fifteen inches in diameter, it can have an arm span of nearly twelve feet and weigh fifty pounds.

Well, there you have it, the biggest invertebrates in the world today. Yikes.