invertebrates
Animals without backbones
Invertebrates are animals without a backbone—the vast majority of animal species, including insects, worms, mollusks, crustaceans, and jellyfish.
The term defines by absence: vertebrates have spinal columns, invertebrates don't.
The tide pool was full of invertebrates.
In casual use, the word sometimes appears as a mild insult suggesting spinelessness.
External skeletal structure
- segmentationDivision into sections
- moltingPeriodic shedding of covering
- metamorphosisProfound biological restructuring
- larvaeImmature metamorphosing creatures
pupae · chitin · ganglia · spiracles · antennae · compound eyes · thorax · abdomen
Drifting marine stinger
- octopusEight-limbed sea mollusk
- squidTen-armed marine mollusk
- crabPincer-bearing shellfish
- lobsterLarge marine shellfish
shrimp · clam · mussel · oyster · sea urchin · starfish · coral · anemone
Shelled, slow-moving mollusk
- slugNaked terrestrial mollusk
- clamSand-dwelling hinged shellfish
- oysterPearl-bearing edible mollusk
- musselEdible two-shelled mollusk
scallop · squid · octopus · nautilus · conch · shell · mantle · tentacles
Web-spinning arachnid
- scorpionStinging arachnid with pincers
- tickParasitic eight-legged pest
- miteMinuscule arachnid parasite
- tarantulaLarge hairy spider
black widow · harvestman · web · venom · fangs · silk · exoskeleton · molting
exoskeleton
External skeletal structure
- segmentationDivision into sections
- moltingPeriodic shedding of covering
- metamorphosisProfound biological restructuring
larvae · pupae · chitin · ganglia · spiracles · antennae · compound eyes · thorax · abdomen · appendages
jellyfish
Drifting marine stinger
lobster · shrimp · clam · mussel · oyster · sea urchin · starfish · coral · anemone · nautilus
snail
Shelled, slow-moving mollusk
mussel · scallop · squid · octopus · nautilus · conch · shell · mantle · tentacles · bivalve
spider
Web-spinning arachnid
- scorpionStinging arachnid with pincers
- tickParasitic eight-legged pest
- miteMinuscule arachnid parasite
tarantula · black widow · harvestman · web · venom · fangs · silk · exoskeleton · molting · cephalothorax
earthworm
Segmented soil-dwelling invertebrate
- leechBlood-feeding aquatic worm
- tapewormSegmented intestinal parasite
- roundwormParasitic cylindrical worm
flatworm · hookworm · ringworm · silkworm · nematode · annelid · segmented · parasitic · compost · soil
beetle
Hard-winged insect
butterfly · moth · fly · mosquito · dragonfly · grasshopper · cricket · cockroach · termite · ladybug