Animal Kingdom-phylums Of Animal Kingdom-class Ix

Symmet Body Special Features Phylums of Animal Kingdom ry Cavity

Characteristics Groups

Body Design

Level of organis ation

Porifera

Acoelomat e

Cellular Level

Coelenterata

Acoelomat eDiploblas tic

Tissue Level

Platyhelmint hes flat worms Nematoda

acoeloma teTriplobl astic

Partiall y organ level

Triploblas tic

Examples

Radially symmetrica l or asymmetric al Radially symmetrica l or biradially symmetrica l Bilaterally symmetrica l

Absent

Non-motile animals attached to some solid support. Pores all over the body, canal system circulates water to bring oxygen and food, outer cover(skeleton) very hard, mostly marine animals.Nervous system absent.

Euplectella, Sycon, Spogilla.

True body cavity absent

Gastrovascular cavity (coelenteron) has a single exterior opening that serves as both mouth and anus. Body made of two layers of cells. Some members colonial (corals) & some solitary(Hydra)

Hydra , Jelly Fish, Sea Anemone

True body cavity absent

Some forms are free living but many are parasitic. Planarians are free living. Tape worm and Liverfluke are parasitic. Body is flattened dorsiventrally ie. From top to bottom, that is why they are called flatworms.

Planaria, Liverfluke, Tapeworm.

Tissue Level

Bilaterally symmetrica l

Cylinderical body. Many nematodes are free living .Some nematodes are parasitic eg. common roundworms, which probably infest more than half the world's humans; hookworms; and filarial worms(Wuchereria), that causes filariasis (elephantiasis)

Ascaris, Wuchereria

Triploblas tic

Organ Level

Bilaterally symmetrica l

False body cavity (Pseudoco elom) Present True Body cavityCOELOMA TE

Nereis, Earthworm, Leech

Triploblas tic

Organ Level

Mollusca

Triploblas tic

Organ Level

Bilaterally symmetrica l AND SEGMENTE D Bilaterally symmetrica l

All members of the group are to some extent segmented, in other words, made up of segments . Segmentation is also called metamerism. Segments each contain elements of such body systems as circulatory, nervous, and excretory tracts. Open Circulatory system- blood does not flow in well defined blood vessels. Coelomic cavity is blood filled and is called HEMOCOEL.

Pila, Octopus, Unio, Chiton

Echinoderm ata

Triploblas tic

Organ Level

Reduced Coelomic cavity, little segmentation, Open circulatory system, Kidney like organs for excretion. Body usually divided into head, dorsal visceral mass and foot. Foot is used for movement. Echinos (greek)=hedgehog, derma=skin; so thses animals are called spiny skinned animals, free living and marine, They have a peculiar water driven tube system used for moving in water(Water vascular system). Hard skeleton of CaCO3

Protochordat a Chordata

Triploblas tic

Organ Level

Bilaterally symmetrica l

True Body cavity COELOMA TE

Notochord present at some stage of life. Mostly marine animals

Balanogloss us, Herdemania

Triploblas tic

Organ Level

Bilaterally symmetrica l

True Body cavity COELOMA

Presence of notochord, single, dorsal, hollow nerve cord,paired gill pouches, post anal tail at some stage of life. ventral heart,

Fish, Man, Birds etc.

(Cnidaria)

cylinderical worms

Annelida segmented worms

Arthropoda (ARTHRO means joints & PODA means legs)

Radial in adults and bilateral at larval stage

True Body cavity COELOMA TE True Body cavity COELOMA TE True Body cavity COELOMA TE

Echinos (greek)=hedgehog

Butterfly, Housefly, Prawn, Scorpion

Antedon, Holothuria, Echinus, Aeterias (Starfish)