Invertebrate
Octopus
The shape-shifting genius of the sea
Invertebrates
The guide features 46 species in the invertebrate class. Each profile answers the most-searched questions first.
What are invertebrates?
Invertebrates are animals without a backbone — a vast group that accounts for around 97% of all animal species. It includes spiders, molluscs, crustaceans, corals, jellyfish, and worms. Lacking an internal skeleton, many rely on hard outer shells, hydrostatic pressure, or exoskeletons for support, and they live in virtually every habitat from the deep sea to the soil beneath our feet.
Invertebrate
Black Widow
Venomous cobweb spider with a red hourglass
Invertebrate
Jellyfish
The ancient, brainless drifter of the seas
Invertebrate
Tarantula
The large, hairy spider with a gentle reputation
Invertebrate
Brown Recluse Spider
The violin-marked spider of the American South
Invertebrate
Blacklegged Tick
The Lyme disease vector of eastern forests
Invertebrate
Coconut Crab
The world's largest land arthropod and tree-climbing island giant
Invertebrate
Giant House Spider
Britain's large but harmless funnel-weaving house spider
Invertebrate
Red Abalone
Critically Endangered nacre snail of Pacific kelp
Invertebrate
Sea Cucumber
Soft recycler of tropical reef sediments
Invertebrate
Sand Dollar
Buried flower of Atlantic sand flats
Invertebrate
Gumboot Chiton
Leathery giant of Pacific tidepools
Invertebrate
Feather Star
Filter-feeding crinoid that walks on cirri
Invertebrate
Brittle Star
Arm-dropping filter feeder of Atlantic gravel
Invertebrate
Box Jellyfish
Cube-shaped killer of Australian shallows
Invertebrate
Moon Jellyfish
Glass-disc drifter of harbours worldwide
Invertebrate
Pistol Shrimp
Cavitation snapper of reef burrows
Invertebrate
Japanese Spider Crab
Record-span scavenger of Pacific depths
Invertebrate
Chambered Nautilus
Vulnerable coiled survivor of deep reefs
Invertebrate
Vampire Squid
Detritus-eating cape of the oxygen minimum zone
Invertebrate
Dumbo Octopus
Fin-flapping octopus of the abyssal plain
Invertebrate
Giant Pacific Octopus
Largest octopus of the North Pacific
Invertebrate
Water Bear
Near-indestructible moss dweller under the microscope
Invertebrate
Velvet Worm
Slime-shooting living fossil of leaf litter
Invertebrate
Sea Angel
Shell-less winged hunter of polar seas
Invertebrate
Crown-of-thorns Starfish
Spiny coral scourge of Indo-Pacific reefs
Invertebrate
Sea Bunny
The tiny nudibranch that went viral for looking like a miniature rabbit
Invertebrate
Cuttlefish
The color-changing master of camouflage
Invertebrate
Black Widow Spider
The glossy black spider with the red hourglass
Invertebrate
Starfish
The five-armed drifter that regrows its limbs
Invertebrate
Blue Crab
The swift swimming crab of Atlantic estuaries
Invertebrate
Peacock Mantis Shrimp
The reef brawler with the fastest punch in nature
Invertebrate
Coral
The tiny reef-building animals of tropical seas
Invertebrate
Atlantic Horseshoe Crab
The ancient living fossil with blue blood
Invertebrate
Jumping Spider
The big-eyed spider that pounces on its prey
Invertebrate
Giant Squid
The elusive deep-sea giant with enormous eyes
Invertebrate
Chambered Nautilus
The living-fossil cephalopod in a spiral shell
Invertebrate
Centipede
The fast, venomous predator with many legs
Invertebrate
American Lobster
The long-lived clawed crustacean of cold seas
Invertebrate
Millipede
The slow, many-legged recycler of the forest floor
Invertebrate
Emperor Scorpion
The large, glowing arachnid with a stinging tail
Invertebrate
Hermit Crab
The crustacean that wears borrowed shells
Invertebrate
Garden Snail
The slow, shell-carrying garden mollusk
Invertebrate
Sea Urchin
The spiny ball that grazes the seabed
Invertebrate
Earthworm
The soil engineer that enriches the earth
Invertebrate
Giant Clam
The reef-dwelling giant of the mollusks
Frequently asked questions
What are invertebrates?
Invertebrates are animals without a backbone — a vast group that accounts for around 97% of all animal species. It includes spiders, molluscs, crustaceans, corals, jellyfish, and worms. Lacking an internal skeleton, many rely on hard outer shells, hydrostatic pressure, or exoskeletons for support, and they live in virtually every habitat from the deep sea to the soil beneath our feet.
How many invertebrates are in the Global Animal Guide?
The Global Animal Guide currently features 46 invertebrates with full, answer-first profiles covering diet, habitat, size, and conservation status.