Who's Who
An animal without a backbone, such as an insect
Invertebrate
Mollusk
Metamorphosis
The four main groups of worms are:
Ribbonworms, flatworms, segmented worms, and roundworms
Animals with spiny skin, sucker feet, and a five-rayed body
Echinoderms
A small sea animal that catches food with stinging tentacles; many life in colonies on coral reefs
Coral
Bivalve
The central body part of an arthropod (between the abdomen and the head)
Thorax
animals that are worm-like and have segmented bodies (example earthworms)
Annelids
Animals with soft bodies; most have shells
Mollusks
A sea animal with an internal skeleton and a body divided into five equal parts, such as a starfish
Echinoderm
An invertebrate with jointed legs and two pairs of antennae, such as a crab
Crustacean
a hard, outer skeleton that surrounds an animal's body
Exoskeleton
Animals that are worm-like and have flat, unsegmented bodies (example: flatworms)
Flatworms (Platyhelminthes)
Animals that have perforated interior walls; most feed on bacteria
Porifera
The umbrella-shaped, swimming stage in the life cycle of jellyfish and other cnidarians.
Medusa
A young animal that develops into an adult by a complete change in body shape
Larva
Long sensory organs on an arthropod's head
Antennae
Animals that have round worm-like bodies with no segments (example roundworms)
Nematodes
animals that have segmented bodies, jointed legs; most have a hard exoskelton
Arthropods
A small sea animal with a hollow cylindrical body and a ring of tentacles around it's mouth; one of the two stages in the life cycle of cnidarians
Polyp
Nymph
The pattern of changes that occur in each generation of a species
life cycle
Animals that live in water and have sack-like bodies with a single opening
Cnidarians
animals whose bodies are supported by a stiff road called a notochord
Chordates