Classification of Classification of AnimalsAnimals

By Uma RaikwarBy Uma Raikwar

Why classify?Why classify?

Think of three examples where we Think of three examples where we group things.group things.

Why do we group these things?Why do we group these things?

TaxonomyTaxonomy

Animals are classified in different Animals are classified in different groups according to their groups according to their similaritiessimilarities and and differencesdifferences..

This is called “taxonomy”.This is called “taxonomy”.

Classifying Living ThingsClassifying Living Things

We put livings things into two large We put livings things into two large groups:groups:

Plants Plants

Animals Animals

AnimalsAnimals

Animals are spilt into two major Animals are spilt into two major groups:groups:

InvertebratesInvertebrates

Vertebrates Vertebrates

InvertebratesInvertebrates

These are animals without a backboneThese are animals without a backbone There are eight groups of invertebratesThere are eight groups of invertebrates

Porifera Porifera Coelentrata Coelentrata PlatyhelminthesPlatyhelminthes NemathelminthesNemathelminthes AnnelidaAnnelida ArthropodaArthropoda molluscamollusca EchinodermataEchinodermata

Porifera-SpongesPorifera-Sponges

Have bodies Have bodies made of loosely made of loosely joined cellsjoined cells

PoriferaPorifera

Latin; Porous – a pore , ferre – to bearLatin; Porous – a pore , ferre – to bear Body has numerous pores called Body has numerous pores called ostiaostia and and

single large pore called single large pore called osculumosculum.. Aquatic, mostly marine, few in fresh water.Aquatic, mostly marine, few in fresh water. Mostly asymmetrical.Mostly asymmetrical. Attached to the substratum, hence Attached to the substratum, hence sessilesessile..

CoelentrataCoelentrata

Have thin sack Have thin sack like bodieslike bodies

Have tentaclesHave tentacles

Coelentrata (Cnidaria)Coelentrata (Cnidaria)

Greek: Greek: Koilas- hollow + intestine Koilas- hollow + intestine

Cnidaria – stinging cellsCnidaria – stinging cells Cylindrical – Polyp or umbrella like - medusa.Cylindrical – Polyp or umbrella like - medusa. Mostly marine some are found in fresh water.Mostly marine some are found in fresh water. Solitary or colonial animals.Solitary or colonial animals. Radially symmetrical and diploblastic.Radially symmetrical and diploblastic. Mouth surrounded by tentacles having stinging Mouth surrounded by tentacles having stinging

cells.cells.

PlatyhelminthesPlatyhelminthes

Have flat worm Have flat worm like bodieslike bodies

PlanariaPlanaria

PlatyhelminthesPlatyhelminthes

Greek: Greek: PlatysPlatys – flat + – flat + helmintheshelminthes – worm. – worm. Dorsoventrally flattened body.Dorsoventrally flattened body. Endoparasites, whereas few are free living.Endoparasites, whereas few are free living. Triploblastic- ectoderm, mesoderm and Triploblastic- ectoderm, mesoderm and

endoderm.endoderm. Hermophrodite- male and female gonads Hermophrodite- male and female gonads

in same animal.in same animal.

NematodaNematodaHave long thin Have long thin

round worm like round worm like bodiesbodies

Have bodies with Have bodies with no segmentsno segments

Nemathelminthes (Nematoda)Nemathelminthes (Nematoda)

Greek: nema- thread + helminthes – Greek: nema- thread + helminthes – wormworm

Long, slender & cylindrical.Long, slender & cylindrical.Free living or endoparasitic.Free living or endoparasitic.Triploblastic, body covered with Triploblastic, body covered with

cuticle.cuticle.Unisexual.Unisexual.

AnnelidaAnnelidaHave elongated Have elongated

bodies divided into bodies divided into segments segments

AnnelidaAnnelida

Latin: Annulus- a little ringLatin: Annulus- a little ring Elongated, cylindrical, segmented.Elongated, cylindrical, segmented. Mostly free living, some are ectoparasites.Mostly free living, some are ectoparasites. Triploblastic, bilaterally symmetrical, coelomates.Triploblastic, bilaterally symmetrical, coelomates. Setae (microscopic) for locomotion.Setae (microscopic) for locomotion. Hermaphrodites, sometimes separate sexes.Hermaphrodites, sometimes separate sexes.

ArthropodaArthropoda

Have lots of legs and segmented Have lots of legs and segmented bodies.bodies.

There are four group of arthropods:There are four group of arthropods:

ArachnidsArachnidsMyriapoda-Centipedes & MillipedesMyriapoda-Centipedes & MillipedesCrustaceansCrustaceansInsectsInsects

Arthropods - ArachnidArthropods - ArachnidHave four pairs of Have four pairs of

legs.legs.Have bodies Have bodies

divided into two divided into two sectionssections

Arthropods – Centipedes Arthropods – Centipedes & Millipedes& Millipedes

Have long thin Have long thin bodies and pairs of bodies and pairs of legs on each of legs on each of their many body their many body sectionssections

Arthropods - CrustaceanArthropods - CrustaceanHave five-seven Have five-seven

pairs of legspairs of legsFirst pair often First pair often

used as pincersused as pincersBodies covered Bodies covered

in shellin shell

Arthropods - InsectsArthropods - InsectsHave three pairs of Have three pairs of

legslegsBodies divided into Bodies divided into

three sectionsthree sectionsOften have wingsOften have wings

MolluscaMollusca

Crawl on a single Crawl on a single fleshy pad.fleshy pad.

Can have a shellCan have a shell

Mollusca Mollusca

Latin: mollis: softLatin: mollis: soft Aquatic or terrestrial.Aquatic or terrestrial. Triploblastic, coelomate.Triploblastic, coelomate. Unsegmented & soft body.Unsegmented & soft body. Bilateral symmetryBilateral symmetry Large muscular foot for locomotion.Large muscular foot for locomotion. Body covered with thick mantle which Body covered with thick mantle which

secretes calcareous shell.secretes calcareous shell. Sexes are separate.Sexes are separate.

EchinodermsEchinoderms

Have bodies divided Have bodies divided into five partsinto five parts

Have spiny outer Have spiny outer coveringcovering

EchinodermataEchinodermata

Greek: Echinos – spines + derma- Greek: Echinos – spines + derma- skinskin

Marine dwelling.Marine dwelling.Triploblastic, radial symmetry in Triploblastic, radial symmetry in

adults.adults.Spines for defence and locomotion.Spines for defence and locomotion.Sexes are separate.Sexes are separate.

ProtochordataProtochordata

ProtochordataProtochordata

Half chordatesHalf chordatesBody is divisible into three regions:Body is divisible into three regions:Proboscis, collar and trunkProboscis, collar and trunkOne to many gill-cleftsOne to many gill-cleftsSexes are separate or may be Sexes are separate or may be

hermaphrodites.hermaphrodites.

VertebratesVertebrates

These are animals with a backbone.These are animals with a backbone.There are six groups of vertebrates:There are six groups of vertebrates:

CyclostomataCyclostomataPiscesPiscesAmphibiaAmphibiaReptiliaReptiliaAvesAvesMammaliaMammalia

CyclostomataCyclostomata

CyclostomataCyclostomata

Suctorial mouth without jaws.Suctorial mouth without jaws.Skin is soft without scales.Skin is soft without scales.Paired appendages – absentPaired appendages – absentCartileginous endoskeleton.Cartileginous endoskeleton.Mostly ectoparasites.Mostly ectoparasites.

PiscesPisces

Have wet Have wet scalesscales

Lays eggs in Lays eggs in waterwater

Lives in waterLives in water

Marine biologists conserving sharks along the Gujarat Marine biologists conserving sharks along the Gujarat coastcoast

PiscesPisces

Cold blooded, aquatic- marine or fresh Cold blooded, aquatic- marine or fresh waterwater

Body is streamlined and boat shaped.Body is streamlined and boat shaped. Paired or unpaired fins present.Paired or unpaired fins present. Tail fin used as rudder.Tail fin used as rudder. Endoskeleton – cartilaginous / bony.Endoskeleton – cartilaginous / bony. Exoskeleton in the form of scales.Exoskeleton in the form of scales. Respiration by gills, eyes without eyelids.Respiration by gills, eyes without eyelids.

AmphibiaAmphibia

Have moist skinHave moist skin Lay jelly coated Lay jelly coated

eggs in watereggs in water Lives on land and Lives on land and

waterwater

AmphibiaAmphibia

Cold blooded freshwater and terrestrial Cold blooded freshwater and terrestrial forms.forms.

Larva- in water and adult on land.Larva- in water and adult on land. Two pairs of limbs and clawless digits.Two pairs of limbs and clawless digits. Skin is moist- mucus glands.Skin is moist- mucus glands. External ear absent, eardrum present.External ear absent, eardrum present. Protruding eyes with eyelids.Protruding eyes with eyelids.

ReptiliaReptilia

Have dry scalesHave dry scalesLay leathery Lay leathery

shelled eggsshelled eggsCold bloodedCold blooded

Sea snakeSea snake

ReptiliaReptilia

Completely terrestrial.Completely terrestrial. Cold blooded. Cold blooded. Underdeveloped limbs, hence crawl.Underdeveloped limbs, hence crawl. Skin is dry and bear bony scales or plates.Skin is dry and bear bony scales or plates. Digits are clawed.Digits are clawed.

AvesAvesHave feathers and Have feathers and

hollow boneshollow bonesLay hard shelled Lay hard shelled

eggseggsWarm bloodedWarm blooded

AvesAves

Aerial mode of life.Aerial mode of life. Warm blooded.Warm blooded. Body is streamlined and spindle shaped.Body is streamlined and spindle shaped. Forelimbs- modified into wingsForelimbs- modified into wings Digits are clawed & covered with scales.Digits are clawed & covered with scales. Endoskeleton made of bones which are Endoskeleton made of bones which are

hollow.hollow. Exoskeleton- of feathers, beak prominent.Exoskeleton- of feathers, beak prominent.

MammaliaMammalia

Have hair and Have hair and produce milkproduce milk

Give birth to live Give birth to live offspring (no eggs)offspring (no eggs)

Warm bloodedWarm blooded

MammaliaMammalia

Presence of mammary glands.Presence of mammary glands.Warm blooded animalsWarm blooded animalsBody divisible into head, neck trunk and Body divisible into head, neck trunk and

tailtailDigits are provided with nails, claws, or Digits are provided with nails, claws, or

hooveshoovesEndoskeleton is bonyEndoskeleton is bonyExoskeleton – hairs or furExoskeleton – hairs or furExternal ear presentExternal ear present

Summary of vertebrataSummary of vertebrata

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