Major Animal Phyla

Biology 103 Animal Lab

Phylum Porifera

• Sponges• Asymmetrical or

Radial symmetry• No organs• Most are Marine• Sessile filter-feeders• Asexual Reproduction

– Fragmentation

• Sexual Reproduction– Hermaphrodites

Phylum Cnidaria

• Cnidarians• Ex. Hydra, Jellyfish,

corals, sea anemone• Radial symmetry• Mostly Marine• Have Nerve Cells• Nematocysts – stinging

tentacles• 2 Body Forms:

– Polyp– Medusa

Polyp

Medusa

Phylum Platyhelminthes

• Flatworms• Bilateral Symmetry• Definite Head• Thin, solid body• Excretory and Digestive

System• Oxygen by diffusion• Hermaphrodites• Ex. Planaria, flukes,

tapeworms

Phylum Nemotoda

• Roundworms• Bilateral symmetry• Tough outer covering• 2 openings• Tube-like digestive

system• Separate sexes• Ex. Nematodes,

hookworms, pinworms

Phylum Mollusca

• Bilateral symmetry• Mostly Marine• 3 body parts: foot, visceral

mass, mantle• Have: heart; digestive,

excretory, and open circulatory systems; gills

• Mostly separate sexes• Ex. Snails(gastropods),

slugs, squid(cephalopods), octopus, clams(bivalves), oysters

Phylum Annelida

• Segmented worms• Aquatic and terrestrial• 2 body openings• Have nervous,

digestive, excretory, and closed circulatory systems; head, nephridia

• Ex. Earthworms, leeches, nereis

Phylum Arthropoda

• Jointed appendages

• Bilateral symmetry

• Exoskeleton

• Separate sexes – internal fertilization in most

• Most diverse phyla

• 4 classes (next 4 slides)

Arachnids

• 2 body sections• 2 pairs of mouth parts

(chelicerae)• 8 legs• Ex. Spiders, ticks,

mites, scorpions

Crustaceans

• 2 pair of antennae

• Aquatic except for pill bug

• Ex. Crabs, lobster, barnacles, shrimp

Myriapods

• Many legs

• Ex. Millipedes & Centipedes

Insects

• 6 legs

• 3 body sections

• Ex. Grasshopper, bee, butterfly

Phylum Echinodermata

• Spiny skin• Bilateral symmetry

as larvae• Radial Symmetry as

adult• Separate sexes• Endoskeleton• Marine• Ex. Starfish, sea

urchins, sand dollars

Phylum Chordata (vertebrates)

• Notochord (nerve cord)

• No vertebrae• Gill slits• Ex. Sea

squirts, lancelets

Phylum Chordata (Vertebrates)

• Have backbone (vertebrae)

• Dorsal nerve cord

• Bilateral symmetry

• Closed circulatory system

• Brain

• 7 classes (next 5 slides)

Fish

• Class Agnatha – Jawless fish

• Class Chondrichthyes – Cartilaginous fish (sharks, rays)

• Class Osteichthyes – Bony fish

Class Amphibia

• Amphibians• Must return to

water to reproduce• Aquatic larvae• Semi-terrestrial

adult• Moist habitat• Ex. Frogs,

salamanders

Class Reptilia

• Reptiles• Dry, scaly skin• 3-chambered heart• Lays amniotic egg

on land• Ectotherms (body

temp. depends on environment

• Ex. Lizards, snakes, turtles

Class Aves

• Birds

• Endotherms (Internal body heat)

• Feathers

• Hollow bones

• 4-chambered heart

Class Mammalia• Mammals• Endotherms• Hair• Milk produced in

mammary glands• Nurse young• 4-chambered heart• Live birth for most

mammals• Highly developed brains• Ex. Mice, Whales,

Humans