KINGDOM ANIMALIA

Animalia kingdom includes all the animals. The name animalia is derived from Latin anima = breath,
soul.
Kingdom Animalia consists of all animals which are multicellular, diploid eukaryotic, ingestive
heterotrophs and develop from two dissimilar haploid gametes, a large egg and a smaller sperm.
Animals are diverse in structure. They range from microscopic worms to blue whales whose weight
is upto 150 tons.
EVOLUTION OF ANIMALS
Animals are believed to have evolved from aquatic protozoan-type ancestors 600 million
years ago or earlier.
Virtually all biologists agree that animals evolved from protoctists; however, which protoctists, when, and in what sort
of environments, are questions that are still actively debated.

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TERMS DESCRIPTION
Protozoa Unicellular animal-like protists
Metazoa Multicellular animals (Kingdom Animalia)
Parazoa Multicellular but lack tissue organization e.g. Phylum Porifera
(sponges)
Eumetazoa Multicellular with tissue organization
Symmetry Arrangement of body organs around central axis
OR
A plane passing through central axis divides body into two equal
halves which are real image to each other
Radial Symmetry Arrangement of body organs around central axis equally
OR
More than one plane passing through central axis divides body into
two equal halves which are real image to each other e.g. Phylum
Cnidaria/Coelenterata
Radial symmetry is adaptation for a sessile life

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Bilateral symmetry Arrangement of body organs around central axis laterally
OR

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A single plane passing through central axis divides body into two
equal halves which are real image to each other
Diploblastic The animals which are composed of two germinal layers i.e. ectoderm
(outer) and endoderm (inner); jelly-like non-cellular mesoglea

Triploblastic
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between ectoderm and Endoderm
The animals which are composed of three germinal layers i.e.
ectoderm (outer), mesoderm (middle) and endoderm (inner)
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Derivatives of germinal layers Ectoderm: integumentary system, nervous system
Mesoderm: muscular system, skeletal system, reproductive system,
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circulatory system, excretory system
Endoderm: gut lining, glands of digestive system (pancreas & liver)
Coelom/Body cavity A fluid filled space between outer body wall and digestive tube
Acoelomates Animals which lack body cavity
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Mesoderm pack solidly between ectoderm and endoderm in the form

of mesenchyme or parenchyme cells e.g. Phylum platyhelminthes
Pseudocoelomates Animals with false body cavity; body cavity is only outer side lined
with mesoderm. So, body cavity is between mesoderm and endoderm
It is developed from blastocoel (an early stage in embryological
of

development).
There is no mesoderm in the gut lining e.g. Phylum aschelminthes
Coelomates Animals with true body cavity; body cavity is lined by mesoderm on
Pr

both outer and inner side.

There is mesoderm also in gut lining along with endoderm e.g.
animals from annelids to chordates

Acoelomate Pattern Pseudocoelomate Pattern Coelomate Pattern

Protostomes During development process the mouth in these animals arises from
the blastopore or from its anterior margin.
Cleavage or division of the zygote is spiral and determinate.
Coelom or the true body cavity is formed due to splitting of
mesoderm (Shizocoelous).
This series proterostomia includes animals belonging to phyla
aschelminthes (nematoda), annelida, mollusca and arthropoda.
Deuterostomes During embryonic development mouth is formed at some distance
anterior to the blastopore and blastopore forms the anus.
Cleavage is radial and indeterminate
Coelom is developed as an out pouching of archenterons
(Enterocoelus)
This series includes animals belonging to phyla Echinodermata,
Hemichordata and Chordata.
Spiral/Determinate Cleavage Cleavage in which the lines or planes of cleavage are not symmetrical
between poles instead these are diagonal to the polar axis and produce
unequal cells around the axis of polarity

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The fate of each blastomere is foretold e.g. Protostomes
Cleavage in which the planes of cleavage are symmetrical to the polar axis

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Radial/Indeterminate Cleavage
and produce tiers of cells on top of each other.
The fate of each blastomere is not pre-determined e.g. Deuterostomes

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Acrania Group of Chordata without cranium or braincase e.g. Subphylum

Urochordata & Cephalochordata
Craniata/Vertebrata Group of Chordata with cranium or braincase; also called vertebrata due to
presence of vertebral column
Agnatha Group of vertebrata which lack jaws and paired appendages e.g. Class
Myxini & Cepalospidomorphi
Gnathostomata Group of vertebrata with jaws and paired appendages
Anamniota The vertebrates which do not have an extra-embryonic membrane
“amnion” are said to be anmniotes and placed in group anamniota
e.g. Fishes & Amphibians
Amniota The vertebrates which have an extra-embryonic membrane
“amnion” are said to be amniotes and placed in group amniota e.g.
Reptiles, Birds & Mammals

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Phylum POREFERA CNIDERIA PLATYHELMINTHES
Naming Porus=Pore; ferra=to bear For Cnidocytes (cells which form Platyhelminthes = flatworm
nematocytes)
Diversity 5000 species (150freshwater)
Body Plan Assymetrical, No tissue and organ Diploblastic; with tissue grade Triploblastic, acoelomates,
level of organization. Outer Layer organization. bilateral symmetry unsegmented
= Pinacoderm Ectoderm: forms outer cover body. Third layer mesoderm
Inner layer =Choanoderm, Middle Endoderm: Internal lining between ectoderm and endoderm
Layer =Gilatenous mesenchyme, Mesenchyme between two layers.
with amoeboid cells+spicules or Arrangement of body parts in
spongin fibers. relationship to centralized axis
(Radial symmetry)
Size Few mm to more than 1m (e.g. Microscopic (hydra) to Few mm (Planaria) – several
Scolymastra joubini) macroscopic (Brancheoceranthus) meters (tapeworm)
Body Cavity Spongocoel; water enters through Single cavity (Gastro-vescular Acoelomates – No body cavity
“ostia” and leaves through cavity or Enteron) with one
“osculum” opening.
Nutrition and Food (20% Zoo- & Phyto- Sac-like digestive system. One Branching, sac-like digestive
Digestion plankton and 80% detrital organic opening mouth surrounded by system. Poorly developed in

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matter); Choanocytes ingest food. tentacles. Stinging cells the parasitic forms or even absent.
nematocysts. Food is immobilized

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and taken into digestive cavity
where it is digested and diffused.
Respiration No system No system No system
Excretion No system No system Branching tubules ending in bulb-
like flame cells.
Circulation
Nervous system
No system
No definite system. Neuro-
sensory or Neurons present to
regulate water flow.
H No special system
Neuron cells forming an irregular
plexus in body wall. No central
nervous system.
No system
Developed CNS; either simple
nerve network or ganglia. Sense
organs are present on anterior
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end.
Locomotion and Sessile; larvae motile. Spicules Mostly sessile, other free living. Free living motile with cilia.
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Skeleton (calcareous or sliacious) Bath Mostly solitary, many colonial Movement restricted in parasites.
sponge has sponging fibers. (aggregations of functionally
different individuals called
zooids.
Many such as corals form
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calcareous exoskeleton.
Reproduction Asexual: Through budding Asexual: by budding (hydra), Asexual: Fission
Sexual: Harmaphrodite Some colonial forms have both Sexual: Hermaphrodite
Protandrous. Fertilization internal sexual zooid ‘medusae’
(developed from blastostyle by
asexual reproduction)
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Alternation of generation with a

diploid asexual attached
generation and a diploid sexual
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free living form.

Development Embryo development includes Larval forms sometime present.
blastula stages
Special features Used for washing & bathing, in Two basic forms: i) Cylindrical Parasitic adaptations: i) No
surgery as water absorbent and sessile “polyp” – gastrozoid,. ii) epidermis ii) Adhesive organs iii)
sound absorption in building. “Medusa” the umbrella like Degenerated nervous and
motile. muscular system iv) Digestion
Polymorphism; occurance of simplified or absent v)
structurally and functionally more complicated reproduction vi)
than two different zooids. More than one host; Infestation &
Disinfestation.
Examples Sycon: marine sponge Hydra: freshwater only polyp. Dugesia (Planaria), Fasciola
Obelia: marine colony
Leucoselenia: erest tubes Aurelia: medusa dominant hepatica (Liver fluke) in bile
Euplectella: venus flower basket Actinia: sea anemone duct, Taenia (tape worm)
Spongilla: freshwater Madrepora: with calcariuos
skeleton – the corels.
Phylum NEMATODA ANNELIDA ARTHROPODA
Naming Nematoda = pointed ends Latin word for “little ring” Arthron=jointed+poda=feet
Diversity Largest phylum
Body Plan Elongated worm-like body. Metamerically segmented. Worm Segmented body; each segment is
Triploblastic, Pseudocoelomates, like body. Segments internally attached to its neighbor by
Head not clearly marked. No divided by septa. Triploblastic flexible cuticle. Rsembling
special sense organs. Bilaterally coelomates with bilateral annelids in having segmented
symmetrical, unsegmented. symmetry. Organ systems re well body, appendages and cuticle.
developed. Exploited every habitat.
Size Microscopic to one meter.
Body Cavity Pseudocoelome derived from True Coelom divided into parietal Coelome is reduced to
Blastocoel (not from Mesoderm). and visceral layer filled with Haemocoel which communicates
Consists of vaculated cells filled coelomic fluid. Divided into the circulatory system.
with protein-rich fluid. segments by septa. Systems such
as gut, blood vessels and nerve
cord are continuous throughout
the length of body.
Nutrition and Alimentary canal with two Alimentary canal with distinct Alimentary canal with mouth and

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Digestion openings; mouth and anus; parts for specific functions having anus. Differentiated for different
simple; Tube within tube. mouth and anus. Mouth overhung functions. Food comprises small
by a lobbed structure

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plants and animals.
“prostomium”
Respiration Gaseous exchange through Through skin, kept moist by Tracheal system with air tubules
general body surface, no specific mucus and coelomic fluid and Trachea opening externally
system. large number of capillaries. through spiracles. Gills and book
lungs in aquatic forms.
Excretion

Circulation
Two longitudinal excretory canals
unite forming a single tube with
anterior opening.
No System H Nephridia – the ciliated organs
present in each segment.

Closed circulatory system. Blood

Malpighian tubules: excretion in
the form of solid uric acid.

Open circulatory system;

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flows in vessels transporting primitive heart and main blood
gases and nutrients. vessel present dorsally. Blood
colorless.
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Nervous system Nerve ring around pharynx giving Well-developed CNS. Solid brain Developed nervous system with
dorsal, ventral and lateral nerve with solid double, longitudinal, paired ganglia connected to
cords. Sensory Papillae on the lip ventral nerve cord with nerves in double ventral nerve cord.
at anterior end. each segment. Ganglion in each segment give
off nerves..
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Locomotion and Undulating waves of contraction Circular and longitudinal muscles Skeleton is external cuticle
Skeleton and relaxation. Four bands of with hydrostatic skeleton. containing light weight chitin
muscles; dorso-lateral and ventro- Circular muscles elongate the attached with muscles and help in
lateral. body longitudinal muscles widen locomotion. Swift movement.
it. Locomotion by Chitinous
chaetae or setae embedded in sacs Fly, swim or crawl. Paired jointed
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or Parapodia. Chaetae are absent appendages and some time wings.

in Leech.
Reproduction Sexes are separate; female Commonly sexual; most are Sexes are separate with ovaries
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gonades are overies and male hermaphrodites. In some (Nereis) and testes.
gonads are testes. sexes are separate.
Development Larval stages presen inlife cycle. Fertilization external and a free Metamorphosis: Complete or
swimming Trochophore larva is incomplete.
produced.
Special features Parasitic mode of life Earthworm is termed as natural Chitin, moulting or ecdysis,
plough. resemblance with Annelids.
Examples Ascaris lumbricoides (intestinal Class Polychaeta: Nereis, Class Crutacea: Daphnia,
parasite). Chaetopterus. Cyclops, Lobster, Prawn, wood
Rhabditis (in soil, organic matter, Class Oligochaeta: Lumbricus louse etc.
water and feces), Enterobius terrestris, Pheretima posthuma Class insecta: Dragonfly,
vermicularis (pin worm) cause
itching of anus and inflammation Class Hirudinea: Hirudo butterfly, moths, wasps etc.
of colon and appendix resulting in medicinalis Class Arachnida: Scorpion,
insomnia and loss of appetite. spiders, mites and ticks etc.
Ancyclostoma duodenale (hook Class Myriapoda: Centipedes,
worm) in small intestine cause Millipedes.
bleeding of villi.
Phylum MOLLUSCA ECHINODERMATA HEMICHORDATA
Naming L. Molluscus=soft Echino+derm =Spinyskinned Hemi = half, also called pre-
chordates
Diversity 50,000 living species, 2nd largest 5000 known species. Exclusively
phylum. Cephalopods are marine organisms living at
exclusively aquatic, terrestrial bottom.
(e.g. land snail) live in moist Mostly free swimming, some
places. attached with substratum.
Body Plan Triploblastic, Coelomate, Triploblastic, coelomates radial Deutrostomes. Sof worm-like
Bilateral Symmetry. Body symmetry in adults but larval body divided into proboscis,
covered by glandular epithelial forms are bilateral, Delicate collar and trunk.
envelop “mantle” that secretes epidermis, mesodermal Unicellular epidermis with
shell. Gills present in cavity endoskeleton with spines. Central mucous secreting cells.
between mantle and shell. Un- disc from which arms radiate. Low level body organization.
segmented body divided into
head, foot and visceral mass.
Size Giant squid is the largest
invertebrate

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Body Cavity Coelom is divided into sinuses for Coelomic cavities correspond to
open blood circulatory system (in three body regions.

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groups other than cephalopods)
Nutrition and Mouth cavity contains rasping Digestive tract straight and may
tongue-like Radula. Gut with two
Digestion openings mouth and anus. show variations.
Respiration Gills in mantle cavity. In some No specialized organs. Gill slits forming dorsal row

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cases (as snails) the mantle cavity behind collar.
is converted into lungs.
Excretion Paired Nephridia No specialized organs. Single glomerulus.
Circulation Except cephalopods, circulatory Water vascular system with tubes Circulatory system with median
system is open. Heart pumps and spaces surrounding the mouth dorsal and median ventral vessels.
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and passing into arms and tube
blood in sinuses. Blue pigment feet. Water enters through
heamocyanin in blood. Madreporite.
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Nervous system Three pairs of interconnected Poorly developed with no brain, Sub-epidermal plexus of cells and
ganglia in head, foot and visceral nerve ring around pharyngeal fibers.
regions. region.
Locomotion and Protective calcareous shell Sac-like tube feet present on the
secreted by mantle; reduced shell edge of grooves in arms.
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Skeleton in active mollusks. A muscular Firm calcareous mesodermal

foot for a slow movement. endoskeleton.
Reproduction Sexes are separate. Sexes are separate with external
fertilization.
Development Trochophore larva (ciliated free Bipinnaria and Brachiolaria
of

swimming) larvae, bilateral symmetry

resembling chordates.
Special features Economic importance: Regeneration is common.
Harmful: Slugs destroy roots, Resemblance to chordates:
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i) radial cleavage ii) anus from

stem and leaves. Shipworms blastopore iii) many common
damage ships. biochemicals e.g. phosphocreatin.
Useful: as food source, in button Afinities to Hemichordata: i)
industry and making roads, Coelom formation, ii) blastopore
making ornaments and getting froms anus(deuterostomous), iii)
pearls. mesoderm by blastopore lip, iv)
mesodermal exoskeleton and
ectodermal exoskeleton.
Examples Gastropoda : (single shell, gills or Asterias (starfish) Balanoglossus
lungs) Helix aspersa (snail) Sea urchin Saccoglossus
Limax sp. (slug)
Bivalvia: (two piece shell, plate Sea cucumber
like gills) Mytilus, Anodonta, Cake urchin
Ostea. Brittle star
Cephalopoda: (Shell reduced &
internal or absent)
Loligo (squid) Sepia (cuttlefish),
Octopus.
 PHYLUM CHORDATA
Notochord:
 This great phylum derives its name from its characteristic feature – the notochord.
 This structure is possessed by all members of the phylum either in the larval or embryonic stages or throughout
life.
 The notochord is a rod-like semi rigid body of vacuolated cells which are filled with proteinaceous material which
extends in most cases the length of the body between enteric canal and the dorsal hollow central nervous system.
Importance of Notochord:
Its primary purpose is to support and to stiffen the body that is to act as skeletal axis.
It seems that the endoskeleton is the chief basic factor in the development and specialization of higher animals.
Examples:
The animals most familiar to us belong to the chordates including man himself.
Basic Characters:
The chordates show great variety and inhabit all kinds of habitat. All chordates possess three basic characters
which are as follows:
1. All possess the notochord.
2. All chordates have central nervous system that is dorsal in position and is hollow.

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3. All chordates develop paired gill openings in embryonic stage. In some these are non-functional, while in other
are functional for some period in their life history e.g. frogs etc. in still others these are functional throughout life

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e.g. Amphioxus, and fishes etc.
4. All chordates have a post anal tail.
Classification
Chordates have been divided into lower chordates e.g. Amphioxus etc. and higher chordates which are the


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vertebrates in which the notochord is replaced by the vertebral column and a bony brain case is also formed due to which
they are also called craniates.
Phylum Chordata have been sub-divided as follows:
Protochordata (Acrania)
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 Sub-phylum Urochordata (1250 species) : Notochord and nerve cord occur only in the free-swimming larvae.
Adults are sessile and enclosed in a covering called tunica. Therefore they are also called tunicates e.g. Molgula.
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 Sub-phylum Cephalochordata (23 species): Notochord and nerve cord extend along the entire length of the body
and persist through out life e.g. Amphioxus (Branchiostoma).
 Sub-Phylum Vertebrata (Craniata)
It includes animals which have cranium in which the brain is enclosed. It includes animals with vertebral
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column that means that all chordates in this group are under subphylum vertebrata. Their number is 43,700 species.

SUPERCLASSES OF VERTEBRATA
1. Pisces (Fishes) which includes class cyclostomata, class chondrichthyes, and class osteichthyes.
2. Tetrapods (Four footed) which includes the classes’ amphibia, reptilia, aves and mammalia.
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SUPERCLASSES OF VERTEBRATA
1. Pisces (Fishes) which includes class cyclostomata, class chondrichthyes, class osteichthyes.
2. Tetrapods (Four footed) which includes the classes amphibia, reptilia, aves and mammalia.
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The former is made up of strictly aqutic forms and the latter of the land dwelling animals. Anmniota and
Amniota:
 The vertbrates which do not have an extra foetal membrane “amnion” are said to be amniotes and placed in
group anamniota.
 The vertbrates which have an extra foetal membrane “amnion” are said to be amniotes and placed in group
amniota.
 SUB-PHYLUM VERTEBRATA
SUPERCLASS AGNATHA SUPERCLASS GNATHOSTOMATA

CLASS MYXINI CLASS CHONDRICHTHYES CLASS OSTEICHTHYES

CEPHALOSPIDOMORPHI
Class Myxini (Hagfishes) and Cartilaginous fishes Bony fishes
Introduction Cephalospidomorphi (Lampreys)
General Lack Jaws and Paired appendages Mouth ventral, olfactory sac not
characteristics connected to mouth cavity
Body, Body wall Long eel-like body Fusiform body  Fins (Median-single or paired)
and locomotion Scales Absent Placoid scales on body  Fin rays of cartilage or bone
In Myxinin: No appendages & No Caudal fin heterocercal  Dermal scales (gnoid, cycloid, or
dorsal fin ctenoid)
In Cephalospidomorphi: No paired  No placoid scales
appendages & one or two median
 Caudal fin homocercal
fins
Cartilaginous Cartilaginous skeleton  Bony skeleton
Skeleton Notochord persistent  Notochord in parts
Ventral sectorial mouth J-shaped stomach  Mouth terminal

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Two rows of eversible teeth in  Jaws with or without teeth
Feeding and Hagfishes
Sucker like oral disc and tongue

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Digestive
system with well-developed teeth in
lampreys
Digestive system lack stomach
Five to sixteen gills in hagfishes 5-7 pairs of gills  Gills supported by gill arches with
Seven pairs of gills each with Swim bladder absent
Respiratory
system

Circulatory
Heart with one auricle H
external gill opening in lampreys

Two chambered heart

5-7 pairs of aortic arches
operculum
Larva (gills)
Adult (lungs an skin)
 Two chambered heart
 Oval & Nucleated RBCs
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system
 Four pairs of aortic arches
Excretory
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system
Sensory organs Dorsal nerve cord with 10 pairs of cranial nerves
and nervous differentiated brain
system
Separate sexes Separate sexes 
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Sexes separate
 Hag fishes (hermaphrodite) Paired gonads  Paired gonads
 External fertilization Internal fertilization
Oviparous or viviparous  Mostly External fertilization
Reproduction Long larval period in lampreys  Most oviparous
 Some viviparous and
ovoviviparous
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Hagfishes  Sharks  Perch

Lampreys  Skates  Trout
Examples  Rays  Plaice
Pr

 Electric ray  Rohu (Labeo rohita)

 Sting ray
 CLASS AMPHIBIA CLASS REPTILIA CLASS AVES
Introduction  Ancestors Dipnoi Adapted to live solely on land Archepteryx (earliest known fossils)

General  At border line between aquatic Embryonic layers (Amnion,  skull large sockets
characteristics and true terrestrial animals Chorion, Allantois)  horny beak, teeth absent
Skin smooth, moist with glands  Dry scaly skin  Stream-lined spindle shaped
Body, Body wall Poisonous pigment cells body
and locomotion Scales absent  Epidermal exoskeleton feathers
Chromatophores (pigment cells)
 Legs bear scales
Bony skeleton Limbs for locomotion  Air spaces in bones
Tailed or without tail  Limbs adapted to flying
Four pentadactyl limbs (4-5 or  Forelimbs (wings)
Skeleton fewer digits)
 Hind limbs (perching)
Legless (caecelians)
Webbed feet (frogs & toads)
 Lack teeth
Feeding and  Horny beak present
Digestive
 Gizzard (grinding)

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system
 Crop (storage)

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Larva (gills) Lungs have extensions called air
Adult (lungs an skin) sacs
Respiratory
system Organ of voice (syrinx) at lower
end of trachea

Circulatory
system
Three chambered heart
Double circulation
H
Sinus venosus & truncus arteriosus
present
 Ventricles incompletely


partitioned
In crocodile completely
 4 chambered heart
 Only right aortic arch
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partitioned
Excretory  Lack bladder
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system  Semi-solid urine
Thermoregulati Poikilotherms (ectotherms) Poikilotherms (ectotherms) Endotherms
on Mostly hibernate in winter
Separate sex  Sexes separate  Separate sexes
External fertilization  Copulatory organ for internal  Internal fertilization
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Larva stage fertilization

Reproduction Metamorphosis
Most oviparous  Amniotic leathery eggs

Frogs  Lizard and snakes, Running birds (Ostrich, Kiwi)

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Toads  Tuatara (sphenodon) Eagle

Salamander
Examples Caecilian
 Crocodiles Sparrow
Mud puppy (Necturus)  Turtles Parrot
Pr

 Tortoise
 CLASS MAMMALIA
 Term by Linnaeus
Introduction
 Highest in animal kingdom
 Nourished by milk
 Reptilian ancestors (Cotylosaurs)
General characteristics  Varnope first retile with 50% mammalian characters
 Dominate in Cenozoic period
 Warm blooded
 Hairs instead of scales
Body, Body wall and
 Muscular diaphragm
locomotion
 Lower jaw with one bone
 External ear or pinna present
Skeleton
 Three bones in ear (Mallaeus, incus and stapes)
Feeding and Digestive  Deciduous (milk) or permanent teeth
system
Respiratory system Voice apparatus (laryns) at upper end of trachea
 4 chambered heart
 Only left aortic arch

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Circulatory system
 RBCs non nucleated

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Metanephric kidney
Excretory system
Thermoregulation Endotherms
 Birth to young (viviparous)
Reproduction
 Mammary glands

Classification 2.
3.
Prototheria:
Metatheria :
Eutheria : H
Mammals are classified into three sub-classes.
1. Egg-laying mammals
Pouched mammals
Placental mammals including man
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 Prototheria (Duck bill platypus, Echidna)
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Examples  Metatheria (Opossum, kangroo and Tasmanian wolf)

 Eutheria (Man, whale, elephant, horse, rat, mice, bat dolphin)
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Pr