Biology: Life on Earth, 5th Edition Teresa and Gerald Audesirk

Comparison of the Major Animal PhylaComparison of the Major Animal PhylaComparison of the Major Animal PhylaComparison of the Major Animal Phyla

Common NameCommon NameCommon NameCommon Name (Phylum)

SpongesSpongesSpongesSponges (Porifera)

Hydra, Anemones, JellyfishHydra, Anemones, JellyfishHydra, Anemones, JellyfishHydra, Anemones, Jellyfish (Cnidaria)

FlatwormsFlatwormsFlatwormsFlatworms (Platyhelminthes)

RoundwormsRoundwormsRoundwormsRoundworms (Nematoda)

Segmented WormSegmented WormSegmented WormSegmented Wormssss (Annelida)

Level of Level of Level of Level of oooorganizationrganizationrganizationrganization

Cellular – lack tissues and organs

Tissue – lack organs Organ system Organ System Organ system

Germ layersGerm layersGerm layersGerm layers Absent Two Three Three Three

SymmetrySymmetrySymmetrySymmetry Absent Radial Bilateral Bilateral Bilateral

CephalizationCephalizationCephalizationCephalization Absent Absent Present Present Present

Body cavityBody cavityBody cavityBody cavity Absent Absent Absent Pseudoceol Coelom

SegmentationSegmentationSegmentationSegmentation Absent Absent Absent Absent Present

Digestive SystemDigestive SystemDigestive SystemDigestive System Intracellular Gastrovascular cavity; some intracellular

Gastrovascular cavity

Separate mouth and anus

Separate mouth and anus

Circulatory Circulatory Circulatory Circulatory SystemSystemSystemSystem

Absent Absent Absent Absent Closed

ReReReRespiratory spiratory spiratory spiratory SystemSystemSystemSystem

Absent Absent Absent Absent Absent

Excretory System Excretory System Excretory System Excretory System (fluid regulation)(fluid regulation)(fluid regulation)(fluid regulation)

Absent Absent Canals with ciliated cells

Excretory gland cells

Nephridia

Nervous systemNervous systemNervous systemNervous system Absent Nerve net Head ganglia with longitudinal nerve

cords

Head ganglia with dorsal and ventral nerve

cords

Head ganglia with paired ventral cords; ganglia in each segment

ReproductionReproductionReproductionReproduction Sexual; asexual (budding)

Sexual; asexual (budding) Sexual (some hermaphroditic);

asexual (body splits)

Sexual (some hermaphroditic)

Sexual (some hermaphroditic)

Body PlanBody PlanBody PlanBody Plan

Internal Internal Internal Internal SystemsSystemsSystemsSystems

SupportSupportSupportSupport Endoskeleton of spicules

Hydrostatic skeleton Absent Hydrostatic skeleton

Hydrostatic skeleton

Biology: Life on Earth, 5th Edition Teresa and Gerald Audesirk

Comparison of the Major Animal PhylaComparison of the Major Animal PhylaComparison of the Major Animal PhylaComparison of the Major Animal Phyla

Common NameCommon NameCommon NameCommon Name (Phylum)

Snails, Clams, SquidSnails, Clams, SquidSnails, Clams, SquidSnails, Clams, Squid (Mollusca)

Insects, Arachnids, CrustaceansInsects, Arachnids, CrustaceansInsects, Arachnids, CrustaceansInsects, Arachnids, Crustaceans (Arthropoda)

Sea Stars, Sea UrchinsSea Stars, Sea UrchinsSea Stars, Sea UrchinsSea Stars, Sea Urchins (Echinodermata)

VertebratesVertebratesVertebratesVertebrates (Chordata)

Level of Level of Level of Level of organizationorganizationorganizationorganization

Organ system Organ system Organ system Organ system

Germ layersGerm layersGerm layersGerm layers Three Three Three Three

SymmetrySymmetrySymmetrySymmetry Bilateral Bilateral Bilateral larvae, radial adults

Bilateral

CepCepCepCephalizationhalizationhalizationhalization Present Present Absent Present

Body cavityBody cavityBody cavityBody cavity Coelom Coelom Coelom Coelom

SegmentationSegmentationSegmentationSegmentation Absent Present Absent Present (but reduced)

Digestive SystemDigestive SystemDigestive SystemDigestive System Separate mouth and anus Separate mouth and anus Separate mouth and anus (normally)

Separate mouth and anus

Circulatory Circulatory Circulatory Circulatory SystemSystemSystemSystem

Open Open Absent Closed

Respiratory Respiratory Respiratory Respiratory SystemSystemSystemSystem

Gills, lungs Tracheae, gills, or book lungs Tube feet, skin gills, respiratory tree

Gills, lungs

Excretory System Excretory System Excretory System Excretory System (fluid regulation)(fluid regulation)(fluid regulation)(fluid regulation)

Nephridia Excretory glands resembling nephridia

Absent Kidneys

Nervous systemNervous systemNervous systemNervous system Well-developed brain in some cephalopods;

several paired ganglia, most in the head; nerve

network in body wall

Head ganglia with paired ventral nerve cords; ganglia in some

segments, some fused

Head ganglia absent; nerve ring and radial

nerves; nerve network in skin

Well-developed brain; dorsal nerve cord

Body PlanBody PlanBody PlanBody Plan

Internal Internal Internal Internal SystemsSystemsSystemsSystems

ReproductionReproductionReproductionReproduction Sexual (some hermaphroditic)

Normally sexual Sexual (some hermaphroditic); asexual by regeneration (rare)

Sexual