| Phylum/Class | General Character | Level of Organisation | Symmetry | Coelom | Segmentation | Development (Direct/Indirect) | Organ Systems | Fertilisation (Internal/External) | Oviparous/Viviparous | Examples |
|---|---|---|---|---|---|---|---|---|---|---|
| Porifera | Primitive multicellular animals with cellular level of organisation; asymmetrical; water transport system; reproduction by fragmentation and gametes | Cellular | Asymmetrical | Acoelomate | Absent | Indirect | Digestive, Respiratory, Reproductive | Internal | Hermaphrodite | Sycon (Sponge), Spongilla (Freshwater sponge), Euspongia (Bath sponge) |
| Coelenterata (Cnidaria) | Radially symmetrical animals with tissue level of organisation; diploblastic; central gastro-vascular cavity; alternation of polyp and medusa forms | Tissue | Radial | Coelenteron | Absent | Indirect | Digestive, Respiratory, Reproductive | External | Dioecious | Physalia (Portuguese man-of-war), Adamsia (Sea anemone), Pennatula (Sea-pen) |
| Ctenophora | Exclusively marine, radially symmetrical, diploblastic organisms with tissue level of organisation; locomotion aided by eight external rows of ciliated comb plates; bioluminescence well-marked | Tissue | Radial | Absent | Absent | Indirect | Digestive, Respiratory | External | Dioecious | Pleurobrachia (Sea walnut), Ctenoplana |
| Platyhelminthes | Dorso-ventrally flattened body; mostly endoparasites found in animals including humans; bilaterally symmetrical, triploblastic, acoelomate animals with organ level of organisation | Organ | Bilateral | Acoelomate | Absent | Indirect | Digestive, Excretory, Reproductive | Internal | Hermaphrodite | Taenia (Tapeworm), Fasciola (Liver fluke) |
| Aschelminthes | Roundworms with cylindrical body and complete digestive system; bilateral symmetry, triploblastic, pseudocoelomate organisms with organ level of organisation | Organ | Bilateral | Pseudocoelomate | Absent | Indirect | Digestive, Excretory, Reproductive | Internal | Dioecious | Ascaris (Roundworm), Wuchereria (Filarial worm), Enterobius (Pinworm) |
| Annelida | Metamerically segmented worms with bilaterally symmetrical, triploblastic, coelomate bodies; true segmentation; well-developed organ systems | Organ | Bilateral | Coelomate | Present | Direct | Digestive, Excretory, Reproductive | External | Dioecious | Pheretima (Earthworm), Hirudinaria (Blood-sucker), Nereis (Sandworm) |
| Arthropoda | Largest phylum with jointed appendages; bilaterally symmetrical, triploblastic, coelomate organisms; body with head, thorax, and abdomen; exoskeleton of chitin; open circulatory system | Organ | Bilateral | Coelomate | Present | Indirect | Digestive, Respiratory, Circulatory, Excretory, Nervous, Reproductive | External | Oviparous | Periplaneta (Cockroach), Anopheles (Mosquito), Scorpion, Prawn, Spider |
| Mollusca | Soft-bodied animals with a muscular foot, mantle, and visceral mass; bilaterally symmetrical, triploblastic, coelomate organisms; mantle secretes calcium carbonate shell | Organ | Bilateral | Coelomate | Present | Indirect | Digestive, Respiratory, Circulatory, Excretory, Nervous, Reproductive | External | Oviparous/Viviparous | Pila (Apple snail), Octopus, Pinctada (Pearl oyster), Unio (Freshwater mussel), Dentalium (Tusk shell) |
| Echinodermata | Marine animals with spiny skin and a unique water vascular system (WVS); pentamerous radial symmetry in adults; bilateral symmetry in larvae; endoskeleton of calcium carbonate plates | Organ | Radial/Bilateral | Coelomate | Pseudocoelomate | Indirect | Digestive, Respiratory, Circulatory, Excretory, Nervous, Reproductive | External | Dioecious | Asterias (Starfish), Antedon (Sea lily), Ophiura (Brittle star), Echinus (Sea urchin) |
| Chordata | Animals possessing a notochord, dorsal hollow nerve cord, pharyngeal gill slits, and post-anal tail at least during embryonic development; triploblastic, coelomate organisms | Organ | Bilateral | Coelomate | Present | Indirect | Digestive, Respiratory, Circulatory, Excretory, Nervous, Reproductive | Internal | Oviparous/Viviparous | Vertebrata (Vertebrates) – Amphibia (Frogs, Toads), Reptilia (Lizards, Snakes, Crocodiles), Aves (Birds), Mammalia (Humans, Dogs, Whales) |
| Amphibia | Moist, glandular skin, capable of respiration through skin; eggs laid in water; undergo metamorphosis from aquatic larva to terrestrial adult; three-chambered heart; ectothermic | Organ | Bilateral | Coelomate | Present | Indirect | Digestive, Respiratory, Circulatory, Excretory, Nervous, Reproductive | External | Oviparous | Rana (Frog), Bufo (Toad), Hyla (Tree frog), Salamandra (Salamander) |
| Reptilia | Scaly skin, terrestrial; respiration through lungs; eggs with leathery shell laid on land; three-chambered heart (except birds and crocodiles which have a four-chambered heart); ectothermic | Organ | Bilateral | Coelomate | Present | Direct | Digestive, Respiratory, Circulatory, Excretory, Nervous, Reproductive | Internal | Oviparous | Varanus (Monitor lizard), Naja (Cobra), Chelone (Turtle), Crocodylus (Crocodile), Hemidactylus (House gecko) |
| Aves | Feathered body; forelimbs modified into wings; beak without teeth; endothermic; four-chambered heart; respiration through lungs; eggs with hard calcareous shell | Organ | Bilateral | Coelomate | Present | Direct | Digestive, Respiratory, Circulatory, Excretory, Nervous, Reproductive | Internal | Oviparous | Pavo (Peacock), Columba (Pigeon), Passer (Sparrow), Gallus (Chicken), Struthio (Ostrich) |
| Mammalia | Warm-blooded animals with mammary glands for milk production; body covered with hair; typically viviparous with internal fertilisation; four-chambered heart; highly developed brain | Organ | Bilateral | Coelomate | Present | Direct | Digestive, Respiratory, Circulatory, Excretory, Nervous, Reproductive | Internal | Viviparous | Homo (Human), Canis (Dog), Felis (Cat), Equus (Horse), Mus (Mouse), Delphinus (Dolphin) |
| Phylum | Class | Subphylum | Superclass | Class | Subclass | General Character | Level of Organization | Symmetry | Coelom | Segmentation | Development (Direct/Indirect) | Organ Systems | Respiratory System and Speciality | Circulatory System and Speciality | Nervous System and Speciality | Skeletal System and Speciality | Excretory System and Speciality | Reproductive System and Speciality | Fertilisation | Sex | Viviparous/Oviparous | Examples (Common Name in Bracket) | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Porifera | Marine, mostly asymmetrical, primitive multicellular, cellular level of organization. Water transport or canal system. Choanocytes line the spongocoel and canals. Intracellular digestion. Supported by a skeleton of spicules or spongin fibers. Hermaphrodite reproduction (asexually by fragmentation, sexually by formation of gametes). Indirect development with a distinct larval stage. | Cellular | Asymmetrical | Acoelomate | None | Indirect | Not elaborated | Internal | Hermaphrodite | Both | Sycon (Scypha), Spongilla (Freshwater sponge), Euspongia (Bath sponge) | ||||||||||||
| Cnidaria | Mostly marine, radial or biradial symmetry. Diploblastic, tissue level of organization. Polyps or medusae body forms. Tentacles with cnidocytes for prey capture and defense. Gastrovascular cavity for digestion and circulation. Nerve net and simple sensory structures. Some species exhibit alternation of generations. Both sexual and asexual reproduction. | Tissue | Radial or Biradial | Coelenteron (gastrovascular cavity) | None | Indirect (with medusa and polyp stages) | Not elaborated | Diffusion (through body surface) | Diffusion (through gastrovascular cavity) | Nerve net and simple sensory structures | Hydrostatic skeleton | Diffusion (through body surface) | Sexual and Asexual (budding) | External | Hermaphrodite | Both | Hydra (Freshwater polyp), Aurelia (Moon jelly), Physalia (Portuguese man o’ war), Gorgonia (Sea fan) | ||||||
| Platyhelminthes | Turbellaria | Marine, freshwater, and damp habitats. Flatworms with bilateral symmetry, triploblastic, organ level of organization. Acoelomate, dorsoventrally flattened body. Incomplete digestive system. Protonephridia for excretion. Nerve ladder and simple cerebral ganglia. Hermaphrodite or monoecious, cross-fertilization. Some species exhibit regeneration. | Organ | Bilateral | Acoelomate | None | Direct | Not elaborated | Diffusion (through body surface) | None (diffusion) | Nerve ladder and simple cerebral ganglia | None | Protonephridia | Sexual and Asexual (regeneration) | Internal | Hermaphrodite | Both | Dugesia (Planaria), Fasciola (Liver fluke), Taenia (Tapeworm) | |||||
| Nematoda | Free-living in soil, freshwater, marine, and parasitic forms. Cylindrical body with tapered ends, bilateral symmetry, triploblastic, organ level of organization. Pseudocoelomate, complete digestive system with a straight tube. Longitudinal muscles only. Dioecious, sexual reproduction, and indirect development with larvae. | Organ | Bilateral | Pseudocoelomate | None | Indirect | Not elaborated | Diffusion (through body surface) | None (pseudocoelom acts as hydrostatic skeleton) | Nerve ring with ventral nerve cord | None | Protonephridia | Sexual | Internal | Dioecious | Both | Ascaris (Roundworm), Wuchereria (Filarial worm), Trichinella (Trichina worm) | ||||||
| Annelida | Polychaeta | Marine, freshwater, and terrestrial habitats. Metamerically segmented body, bilateral symmetry, triploblastic, organ level of organization. Coelomate, complete digestive system with regional specializations. Closed circulatory system with segmental hearts. Well-developed nervous system with ventral nerve cord and cerebral ganglia. Dioecious, sexual reproduction, and indirect development with trochophore larva. | Organ | Bilateral | Coelomate | Metameric | Indirect | Complete | Gills (aquatic), Skin (terrestrial) | Closed (segmental hearts) | Ventral nerve cord and cerebral ganglia | Hydrostatic skeleton | Nephridia | Sexual | Internal | Dioecious | Both | Nereis (Ragworm), Aphrodite (Earthworm), Hirudinaria (Leech) | |||||
| Mollusca | Gastropoda | Marine, freshwater, and terrestrial habitats. Soft-bodied animals often with a hard shell, bilateral symmetry, triploblastic, organ level of organization. Coelomate, complete digestive system with regional specializations. Open circulatory system with a heart and blood vessels. Well-developed nervous system with cerebral ganglia. Dioecious, sexual reproduction, and direct development or with a trochophore larva. | Organ | Bilateral | Coelomate | None | Direct or with trochophore larva | Complete | Gills (aquatic), Skin (terrestrial) | Open (heart and blood vessels) | Cerebral ganglia | Exoskeleton or reduced shell | Nephridia | Sexual | Internal | Dioecious | Both | Patella (Limpet), Helix (Garden snail), Aplysia (Sea hare) | |||||
| Mollusca | Bivalvia | Mostly marine, some freshwater and terrestrial species. Laterally compressed body enclosed in a hinged shell, bilateral symmetry, triploblastic, organ level of organization. Coelomate, complete digestive system with regional specializations. Open circulatory system with a heart and blood vessels. Reduced nervous system. Dioecious, sexual reproduction, and indirect development with a trochophore and veliger larva. | Organ | Bilateral | Coelomate | None | Indirect (with trochophore and veliger larva) | Complete | Gills (aquatic), None (terrestrial) | Open (heart and blood vessels) | Reduced | Exoskeleton or reduced shell | Nephridia | Sexual | Internal | Dioecious | Both | Mytilus (Mussel), Pinctada (Pearl oyster), Arca (Ark shell) | |||||
| Mollusca | Cephalopoda | Marine habitat, active predators with a head surrounded by tentacles, bilateral symmetry, triploblastic, organ level of organization. Coelomate, complete digestive system with regional specializations. Closed circulatory system with a heart and blood vessels. Well-developed nervous system with large brain and eyes. Dioecious, sexual reproduction, and direct development. | Organ | Bilateral | Coelomate | None | Direct | Complete | Gills | Closed (heart and blood vessels) | Well-developed nervous system with large brain and eyes | Exoskeleton or reduced shell | Nephridia | Sexual | Internal | Dioecious | Both | Octopus, Loligo (Squid), Sepia (Cuttlefish) | |||||
| Arthropoda | Arachnida | Terrestrial, marine, and freshwater habitats. Body divided into cephalothorax and abdomen, bilateral symmetry, triploblastic, organ level of organization. Coelomate, complete digestive system with regional specializations. Open circulatory system with a heart and arteries. Well-developed nervous system with cerebral ganglia. Dioecious, sexual reproduction, and indirect development with larval stages. | Organ | Bilateral | Coelomate | Metamerism present | Indirect (with larval stages) | Complete | Book lungs (terrestrial), Gills (aquatic) | Open (heart and arteries) | Cerebral ganglia | Exoskeleton (chitinous) | Malpighian tubules | Sexual | Internal | Dioecious | Both | Latrodectus (Black widow), Tegenaria (House spider), Araneus (Garden spider) | |||||
| Arthropoda | Insecta | Terrestrial, freshwater, and aerial habitats. Three distinct body regions: head, thorax, and abdomen, bilateral symmetry, triploblastic, organ level of organization. Coelomate, complete digestive system with regional specializations. Open circulatory system with a heart and arteries. Well-developed nervous system with cerebral ganglia. Dioecious, sexual reproduction, and indirect development with larval stages. | Organ | Bilateral | Coelomate | Metamerism present | Indirect (with larval stages) | Complete | Tracheae (terrestrial), Spiracles (aquatic) | Open (heart and arteries) | Cerebral ganglia | Exoskeleton (chitinous) | Malpighian tubules | Sexual | Internal | Dioecious | Both | Drosophila (Fruit fly), Apis (Honey bee), Bombyx (Silkworm) | |||||
| Arthropoda | Crustacea | Mostly aquatic, some terrestrial species. Body divided into cephalothorax and abdomen, bilateral symmetry, triploblastic, organ level of organization. Coelomate, complete digestive system with regional specializations. Open circulatory system with a heart and arteries. Well-developed nervous system with cerebral ganglia. Dioecious, sexual reproduction, and direct or indirect development with larval stages. | Organ | Bilateral | Coelomate | Metamerism present | Direct or indirect (with larval stages) | Complete | Gills | Open (heart and arteries) | Cerebral ganglia | Exoskeleton (chitinous) | Green gland | Sexual | Internal | Dioecious | Both | Homarus (Lobster), Carcinus (Crab), Artemia (Brine shrimp) | |||||
| Echinodermata | Asteroidea | Starfish or Sea stars | Pentaradial symmetry | Calcium carbonate ossicles | Marine habitat, mostly benthic | Water vascular system, tube feet | Organ | Pentaradial | Coelomate | Metamerism absent | Indirect (bipinnaria larva) | Complete | Respiratory trees | Open (water vascular system) | Nerve ring | Endoskeleton (ossicles) | None | Sexual | External | Dioecious | Both | Asterias (Common starfish), Pisaster (Ochre star) | |
| Echinodermata | Ophiuroidea | Brittle stars | Pentaradial symmetry | Calcium carbonate ossicles | Marine habitat, mostly benthic | Water vascular system, tube feet | Organ | Pentaradial | Coelomate | Metamerism absent | Indirect (ophiopluteus larva) | Complete | Respiratory trees | Open (water vascular system) | Nerve ring | Endoskeleton (ossicles) | None | Sexual | External | Dioecious | Both | Ophiocoma (Brittle star), Ophiothrix (Serpent star) | |
| Echinodermata | Echinoidea | Sea urchins, sand dollars, heart urchins | Pentaradial symmetry | Calcium carbonate ossicles (tests) | Marine habitat, mostly benthic | Water vascular system, tube feet | Organ | Pentaradial | Coelomate | Metamerism absent | Indirect (echinopluteus larva) | Complete | Respiratory trees | Open (water vascular system) | Nerve ring | Endoskeleton (tests) | Aristotle’s lantern | Sexual | External | Dioecious | Both | Strongylocentrotus (Sea urchin), Echinocardium (Heart urchin) | |
| Echinodermata | Crinoidea | Sea lilies, feather stars | Pentaradial symmetry | Calcium carbonate ossicles | Marine habitat, mostly sessile | Water vascular system, tube feet | Organ | Pentaradial | Coelomate | Metamerism absent | Indirect (pluteus larva) | Complete | Respiratory trees | Open (water vascular system) | Nerve ring | Endoskeleton (ossicles) | None | Sexual | External | Dioecious | Both | Antedon (Sea lily), Comanthus (Feather star) |
| Phylum | Common Name | Level of Organisation | Symmetry | Diploblastic/Triploblastic | Coelom | Coelom Type | Segmentation | Notochord | Body Cavity | Digestive System | Circulatory System | Respiratory System | Excretory System | Reproductive System | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Porifera | Sponges | Cellular | Asymmetrical | N/A | Acoelomate | N/A | N/A | Absent | None | Incomplete | None | None | None | None | |
| Cnidaria | Jellyfish, Coral | Tissue level | Radial | Diploblastic | Coelomate | Enterocoelous | N/A | Absent | Gastrovascular | Incomplete | Open | Diffusion | Diffusion | Both sexual and asexual | |
| Platyhelminthes | Flatworms | Organ level | Bilateral | Triploblastic | Acoelomate | N/A | N/A | Absent | None | Incomplete | N/A | N/A | N/A | Complex | |
| Nematoda | Roundworms | Organ level | Bilateral | Triploblastic | Pseudocoelomate | Surrounded by mesoderm | N/A | Absent | Pseudocoelom | Complete | N/A | N/A | None | Dioecious | |
| Annelida | Segmented Worms | Organ system level | Bilateral | Triploblastic | Coelomate | Schizocoelous | Present | Absent | Coelom | Complete | Closed | Diffusion | Metanephridia | Dioecious | |
| Arthropoda | Arthropods | Organ system level | Bilateral | Triploblastic | Coelomate | Schizocoelous | Present | Exoskeleton | Coelom | Complete | Open | Tracheal system | Malpighian tubules | Dioecious | |
| Mollusca | Molluscs | Organ system level | Bilateral | Triploblastic | Coelomate | Schizocoelous | Present | Present | Coelom | Complete | Open | Gills | Nephridia | Dioecious | |
| Echinodermata | Starfish, Sea Urchin | Organ system level | Pentaradial | Triploblastic | Coelomate | Enterocoelous | Present | Present | Coelom | Complete | Open | Tube feet | Madreporite | Dioecious | |
| Chordata | Vertebrates | Organ system level | Bilateral | Triploblastic | Coelomate | Schizocoelous | Present | Present | Coelom | Complete | Closed | Lungs/gills | Kidneys | Dioecious | Chordata | Urochordata (Tunicates) | Organ system level | Bilateral | Triploblastic | Coelomate | Schizocoelous | N/A | Present | Coelom | Complete | Closed | N/A | N/A | N/A |
| Cephalochordata (Lancelets) | Amphioxus | Organ system level | Bilateral | Triploblastic | Coelomate | Schizocoelous | N/A | Present | Coelom | Complete | Closed | N/A | N/A | N/A | |
| Myxini (Hagfish) | Hagfish | Organ system level | Bilateral | Triploblastic | Coelomate | Schizocoelous | Present | Present | Coelom | Complete | Closed | N/A | N/A | N/A | |
| Petromyzontida (Lampreys) | Lampreys | Organ system level | Bilateral | Triploblastic | Coelomate | Schizocoelous | Present | Present | Coelom | Complete | Closed | N/A | N/A | N/A | |
| Gnathostomata (Jawed vertebrates) | Fish, Amphibians, Reptiles, Birds, Mammals | Organ system level | Bilateral | Triploblastic | Coelomate | Schizocoelous | Present | Present | Coelom | Complete | Closed | Gills or Lungs | Kidneys | Dioecious | |
| Ostracodermi | Ostracoderms | Organ system level | Bilateral | Triploblastic | Coelomate | Schizocoelous | Present | Present | Coelom | Complete | Closed | N/A | N/A | N/A | |
| Gnathostomata (Jawed vertebrates) | Fish, Amphibians, Reptiles, Birds, Mammals | Organ system level | Bilateral | Triploblastic | Coelomate | Schizocoelous | Present | Present | Coelom | Complete | Closed | Gills or Lungs | Kidneys | Dioecious | |
| Osteichthyes | Bony Fishes | Organ system level | Bilateral | Triploblastic | Coelomate | Schizocoelous | Present | Present | Coelom | Complete | Closed | N/A | N/A | N/A | |
| Amphibia | Amphibians | Organ system level | Bilateral | Triploblastic | Coelomate | Schizocoelous | Present | Present | Coelom | Complete | Closed | Through skin and lungs | N/A | N/A | |
| Reptilia | Reptiles | Organ system level | Bilateral | Triploblastic | Coelomate | Schizocoelous | Present | Present | Coelom | Complete | Closed | Lungs | N/A | N/A | |
| Aves | Birds | Organ system level | Bilateral | Triploblastic | Coelomate | Schizocoelous | Present | Present | Coelom | Complete | Closed | Lungs | N/A | N/A | |
| Mammalia | Mammals | Organ system level | Bilateral | Triploblastic | Coelomate | Schizocoelous | Present | Present | Coelom | Complete | Closed | Lungs | Kidneys | Dioecious |