Major Animal Phyla

A chordate ( KOR-dayt) is a bilaterian animal belonging to the phylum Chordata ( kor-DAY-tə).

Arthropods ( AR-thrə-pod) are invertebrates in the phylum Arthropoda.

Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks ().

Cnidaria ( nih-DAIR-ee-ə, ny-) is a phylum of animals containing over 11,000 species of aquatic invertebrates found both in freshwater and marine environments (predominantly the latter), including jellyfish, hydroids, sea anemones, corals and some of the smallest marine parasites.

An echinoderm () is any animal of the phylum Echinodermata (), which includes starfish, brittle stars, sea urchins, sand dollars and sea cucumbers, as well as the sessile sea lilies or "stone lilies". While bilaterally symmetrical as larvae, as adults echinoderms are recognisable by their usually five-pointed radial

Annelids (), also known as segmented worms, are animals that comprise the phylum Annelida (; from Latin anellus 'little ring').

Platyhelminthes (from Ancient Greek πλατύ (platy) 'flat' and ἕλμινς (helmins) 'parasitic worm') is a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrates commonly called flatworms or flat worms.

The nematodes ( NEM-ə-tohdz, NEE-mə-), roundworms or eelworms constitute the phylum Nematoda (Ancient Greek: Νηματώδη; Latin: Nematoda).

Sponges or sea sponges are primarily marine invertebrates of the animal phylum Porifera (; meaning 'pore bearer').