Coelenterata (Cnidaria)	Platyhelminthes	Nematoda	Annelida	Mollusca	Arthropoda	Echinodermata
Marine or freshwater	Free-living forms inhabit water or moist soil, parasites inside the host body	Found in soil, water and as parasites.	Found in marine, freshwater or on/in soil	Mostly marine or freshwater,  Some terrestrial	Terrestrial or aquatic	Exclusively marine
Radial symmetry	Bilateral symmetry					Adults: penta radial symmetry Larvae :bilateral symmetry
Diploblastic	Triploblastic
Mesoglea present between two germ layers	No body cavity	Pseudocoelom present	Well developed coelom	Haemocoel (Coelom reduced)	Haemocoel (Coelom greatly reduced )	Large coelom. A part is developed as water vascular system with associated tube feet
Two types of body form-tube like polyp, umbrella like medusa No segmentation	Dorsoventrally flattened body. No segmentation	Slender,cylindrical tapered end body. No segmentation	Cylindrical worm like body internal and external segmentation	A little trace of segmentation Different types of body forms	Externally segmented body. Each segment typically bears a pair of  jointed appendages.	Cylindrical or star or flower like form.  No segmentation
Cephalization absent	Shows some degree of cephalization	Shows some degree of cephalization	Shows cephalization	Clear cephalization. Body is divided into head, muscular  foot, visceral mass	Distinct cephalization, parts of body; generally divided into head, thorax & abdomen	No cephalization Body is arranged in oral aboral axis
Nematocysts present in cell layer. No cuticle	Epidermis soft and ciliated or covered by cuticle and with external suckers or hooks or both	Tough cuticle is present	Definite cuticle and chetae of chitin Body  covering  is soft and it forms a mantle		Exoskeleton of chitin secreted by epidermis	Body covered by delicate epidermis often with spines
Corals posses limy or horny Exoskeleton	No skeleton	Hydrostatic skeleton of pseudocoelomic fluid	Hydrostatic skeleton of coelomic fluid	Many have Exoskeleton, In some endoskeleton	exoskeleton	endoskeleton
		Lacks cilia at any stage			Lacks cilia at any stage
Gastro vascular cavity	Incomplete alimentary canal. Only mouth no anus	Complete Alimentary canal having mouth & anus				Complete alimentary tract in some. Some lack anus
				Radulla present in some	Mouth parts present
No circulatory system			Closed circulatory system with lateral hearts	Open circulatory system with dorsal heart		Reduced circulatory system
No respiratory organs			Some have external gills	Gills or ctenidia in the mantle cavity for respiration. Land forms respire through mantle	Gills or book lungs or trachea as respiratory structures	Gills or papillae or tube feet or cloacal respiratory tree as respiratory structure
No excretory system	Simple excretory system with flame cells & ducts	Simple excretory system with longitudinal canals	Excretory structures: nephridia		Green gland or malphigian tubules	No excretory system
Nerve net	A pair of anterior ganglia or a nerve ring with  longitudinal nerve cords (1-3)	Nerve ring with longitudinal nerve cords	One pair of cerebral ganglia & double, solid, mid ventral nerve cord	Nerve ring with  pairs of ganglia & 2 pairs of nerve cords	Paired dorsal cerebral ganglia & double ventral solid nerve cord	Nervous system with nerve rings  and radial  nerves
Some with eyespots and/or statocysts as sensory structures	Free living forms have eyespots & chemoreceptors	Mainly papillae	Simple eyes. tentacles and palps in some	Sensory Organs Tentacles, Some have eyes,eyespots and statocysts	Antennae, statocysts sensory hairs simple and compound eyes	Most do not have sensory organs. Some have  tactile tube feet  eye spots & sensitive  tentacles
Simple gonads without ducts	Gonads, gonadal ducts, accessory organs present	Gonads with ducts	Gonads and ducts	Gonads & ducts	Gonads & ducts	Large gonads with ducts
Asexual reproduction by budding or regeneration	Asexual reproduction in some forms by fragmentation	No asexual reproduction or regeneration	In some by budding or regeneration		In some regeneration	In some regeneration
Unisexual/ bisexual	Usually bisexual	Unisexual	Unisexual or bisexual	Usually unisexual	Unisexual  By parthen ogenesis in some insects and crustaceans	Unisexual
External fertilization	Internal fertilization	Internal fertilization	External  or internal fertilization	External or internal	Mostly internal	External fertilization
Planula larva	Many larval Stages in parasites.Free living forms have no larval stages	Larval Stage in some	Trochophore larva	Trochophore or veliger larva	One or more larval stages	Bipinnaria or dipleurula larva

Hydrozoa	Scyphozoa	Anthozoa
Dominant stage- polyp which is solitary or colonial, medusa is small & free swimming	Dominant stage-medusa which is umbrella shaped & free swimming, polyp stage is minute or lacking	Polyp stage only ,which is solitary or colonial , No medusa stage
A circle of tentacles around mouth	Four oral arms around mouth , Tentacles on the edge	Many tentacles around mouth in many circles
E.g., Hydra , Obelia	E.g., Aurelia  (jelly fish)	E.g.,Sea anemone ,  Corals

Turbellaria	Trematoda	Cestoda
Free living	Endoparasitic  or ectoparasitic	Endoparasitic
Leaf like body.Eye spots  present	Leaf like body, No eyespots in adults	Slender, elongated,flat  body divided into scolex and proglottids, no eye spots
Ventral mouth with protrudable pharynx, No suckers	Ventral sucker or suckers  on ventral side and oral sucker surrounds mouth	Suckers and hooks on scolex. No mouth
Ciliated epithelium with mucus glands	Cuticle with spines	Cuticle with microvilli
E.g.,  Planaria ,Bipalium	E.g., Fasciola (liver fluke)	E.g., Taenia (tape worm)

Polychaeta	Oligochaeta	Hirudinea
Distinct head with eyes and tentacles	No distinct head	No distinct head, having anterior and posterior suckers
Presence of parapodia	No parapodia	No parapodia
Numerous setae	Fewer number of setae	No setae
No clitellum	Clitellium present	No clitellum
E.g. Nereis	E.g. Earth worm	E.g. Leech

Polyplacophora	Bivalvia	Gastropoda	Cephalopoda
Dorsal shell  formed by 8 over – lapping plates	Shell of two lateral valves	Univalved shell usually coiled,In  some shells are reduced or absent	Shell external, internal or none
Radula present	No radula	Radula present	Radula present
Large, flat foot	Hatchet shaped foot	Largely developed foot	Foot is modified into arms, tentacles  and siphon
Head is present, without eyes or Tentacles. In some eye spots present	No head  No eyes No tentacles	Head is present with tentacles and eyes  Eyes on one pair of tentacles	Head is present with conspicuous eyes and 8-10 arms
E.g.,Chiton	E.g.,Mussels , Oyster	E.g.,Snail , Slug	E.g.,Squid , Octopus

Crustacea	Insecta	Chilopoda	Diplopoda	Arachnida
Body is divided into cephalothorax and abdomen	Head, thorax and abdomen distinct	Head followed by numerous segments of body	Head, short thorax  abdomen	(prosoma) cephalo – thorax and abdomen (opisthosoma)(except in ticks)
One pair of appendages per somite	3 pairs of legs on thorax one/two pairs of wings.Some without wings	One pair of legs per somite of the body. Poison claws present	Two pairs of legs per somite in the abdomen	4 pairs of legs on cephalothorax (prosoma)
Two pairs of antennae	One pair of antennae	One pair of long  antenna	One pair of short antenna	No antennae
E.g. prawn , crab	E.g. cockroach  (any insect)	E.g. Centipede	E.g. Millipede	E.g. Scorpion , Spider , Tick , Mite

Asteroidea	Ophiuroidea	Echinoidea	Holothuroidea	Crinoidea
Consists of a central disc and five tapering arms,each with a longitudinal central groove (ambulacral groove)	Small rounded disc with five distinct arms which are long,slender  fragile & jointed,closed ambulacaral groove	No arms:  Rounded  or flat body	Elongated cylindrical slender body	Body is a small cup shaped calyx of limy (calcified)plates to which five flexible arms (each with a longitudinal ambulacral groove) are attached.  Some have stalks
On the upper surface there are many blunt calcareous spines and pedicellaria,Many gills present	No pedicellaria Spines in lateral side of arm	Movable spines and pedicellaria. Ten gills around mouth	No spines or pedicellaria	Bearing many slender lateral pinnules.  No spines
Mouth is in the lower(oral) surface & anus is in the upper(aboral) surface	Mouth is centered & no anus	Mouth oral (ventral surface) & anus aboral(dorsal surface)	Mouth anterior. Anus posterior	Mouth and anus on oral (upper) surface
Tube feet with suckers are present in the oral surface	Tube feet with no suckers in  two rows	Slender tube feet with suckers	Tube feet usually present with suckers	Tentacle like tube feet
E.g., Star fish	E.g., Brittle star	E.g., Sea urchin , Sand dollar	E.g., Sea cucumber	E.g., Sea lily

Chondrichthyes	Osteichthyes	Amphibia	Reptilia	Aves	Mammalia
Spindle shaped body divided into head , trunk and tail.	Spindle shaped body divided into head ,trunk and  tail.	Body comprises head and trunk Some have a tail	Head, neck, trunk and tail,	Stream lined body divided into head, neck, trunk,  tail	Body with head, neck, trunk & tail. Differ in forms
Skin with placoid scales	Skin with placoid scales	Soft skin with glands	Skin dry with horny scales or horny plates,No skin glands	Skin bears feathers ;legs have scales	Skin bears hairs and glands
Paired pectoral  & pelvic fins		Paired pentadactyl limbs		Paired pentadactyl limbs; front pair form wings	Paired pentadactyl limbs; front pair form wings
Heterocercal caudal fin	Homocercal  caudal fin	Some adults have tail . All larval forms have tails	Post anal tail covered with scales	Short tail bears long tail feathers	Tails are of diverse forms.Some have tails only in embryo
Ventral mouth with enamel capped teeth	Usually terminal mouth with teeth which are bony	Ventral mouth. If teeth are present they are fastened to the surface of bones	Wide mouth margined with teeth, in some teeth in sockets	Mouth is extended as beak;. no teeth	Ventral mouth with teeth in sockets

 

 

 

 

 

Chondrichthyes	Osteichthyes	Amphibia	Reptilia	Aves	Mammalia
Inner ear only;  no middle or external ear	Inner ear  only;no middle or external ear	Inner and middle ear only;  no external ear	Inner ,middle and  external ear	Inner ,middle and  external ear	External, middle and inner ear. Pinna present
Cartilaginous skeleton.	Bony skeleton Largely bony skeleton	Largely bony skeleton	Completely ossified skeleton	Skeleton light, strong, fully ossified with air cavities	Skeleton largely of bony with cartilage articulating over surfaces
Eyes usually well developed without lids,lateral line present	Eyes usually well  developed without lids. lateral line present	Eyes often with movable lids.  Nictitating membrane present. Lateral line in larvae	Large  lateral eyes with eye lids and nictitating membrane	Large and lateral eyes with eye lids and nictitating membrane	Eyes with movable lids some have nictitating membrane. In some it is vestigial
Two chambered heart	Two chambered heart	Three chambered heart	Three chambered heart	Four chambered heart	Four chambered heart
Respiration by gills ,several gill openings.No operculum	Respirtion by gills, pair of gill openings.Gill covered by operculum	Respiration by gills, lungs, skin or Buccal cavity lining	Respiration by lungs
Excreation by kidney,major nitrogenous waste is urea	Excreation by kidney, major nitrogenous waste is urea-for marne forms, NH3 for fresh water forms	Excreation by kidney, major nitrogenous waste is urea for adults, NH3 for larvalforms	Excreation by kidney, major nitrogenous waste is uric acid		Excreation by kidney, major nitrogenous waste is urea
Poikilothermic				Homoeothermic
Ten pairs of cranial nerves			Twelve  pairs of cranial nerves

 

 

 

 

 

Chondrichthyes	Osteichthyes	Amphibia	Reptilia	Aves	Mammalia
No larval stage; oviparous or ovoviviparous;	Larval stage may be present; usually oviparous;	Larval stage usually present. Oviparous	No larval stage.  Oviparous  or ovoviviparous ; yolky eggs in shells	No larval stage. Yolky eggs in calcareous shells; oviparous.	No larval stage. Embryo develop within mother. Viviparous , some are oviparous . young feed on milk produced by the mammary glands of mother
Internal fertilization	External fertilization	External or internal fertilization	Internal fertilization	Internal fertilization	Internal fertilization
E.g.: shark , skate	E.g.: mullet , Tuna , Carangids ,Tilapia	E.g.: toad , frog , salamander , Ichthyophis	E.g.: lizard , Cobra , crocodile , turtle  ,tortoise	E.g.: parrot , crow , Ostrich  (Any bird)	E.g.: rat , man , whale , sea lion , platypus , bat  (Any animal that feeds on mother’s milk)