Kingdom Animalia

Kingdom AnimaliaGeneral CharacteristicsMulticellularNo cell walls (bodies are held together by proteins such as collagen).Often contain specialized tissue such as nervous and muscle tissue.All are heterotrophicOften motile

Animal BodiesThe bodies of most animals (all except sponges) are made up of cells organized into tissues.Each tissue is specialized to perform specific functions.In most animals, tissues are organized into even more specialized organs.

Radial vs. Bilateral symmetryRadialCan be divided into similar halves by more than two planes passing through it.Usually sessile, free-floating, or weakly swimmingPrimitive animalsCnidariansEchinodermsBilateralHave a left and right sidewell-suited for directional movementMost animals

CephalizationBilateral Symmetry usually has led to cephalizationthe process by which sensory organs and appendages became localized in the head end of animals.

3 Major Bilateral Body PlansAcoelomatesPseudocoelomatesCoelomates

Each plan consists of 3 cell layers:EndodermMesoderm Ectoderm

AcoelomatesThese animals have no other cavity than the gut.They are often called the solid worms.

PseudocoelomatesThese animals have a body cavity (the pseudocoelom) which is not completely lined with mesoderm.The tube within a tube body plan.This category is also composed of mostly worms.

CoelomatesThese animals have a true coelom lined with mesodermal peritoneum.Most animals are coelomate.

Early development

Protostomes vs. Deuterostomes

Animal NumbersIt is estimated that somewhere around 9 or 10 million species of animals inhabit the earth. About 800,000 species have been identified.These have been grouped into 36 separate phyla in the animal kingdom.Porifera

Cnidaria

Platyhelminthes

Nematoda

Mollusca: Gastropoda

Mollusca: Pelycopoda

Mollusca: Cephalopoda

Annelida: Polychaeta

Annelida: Oligochaeta

Annelida: Hiridinea

Arthropoda: Crustacea

Arthropoda: Arachnida

Arthropoda: Chilopoda

Arthropoda: Diplopoda

Arthropoda: Insecta

Echinodermata: Crinoidea

Echinodermata: Astroidea

Echinodermata: Echinoidea

Echinodermata: Holothuroidea

Chordata: Subphylum Urochordata

Chordata: Subphylum Cephalochordata

Chordata: Subphylum Vertabrata Have a backboneMajor classes:AgnathaChondrichthyesOsteichthyesAmphibiaReptiliaAvesMamaliaAgnatha

Chondrichthyes

Osteichthyes

Amphibia

Reptilia

Aves

Mammalia

Chart29000005000020000120001200011000900060006000

Sheet1Arthropoda900000Mollusca50000Chordata20000Cnidaria12000Platyhelminthes12000Nematoda11000Annelida9000Porifera6000Echinodermata6000

Sheet1000000000

Sheet2

Sheet3