AVES-CLASS, VERTEBRATA

*about 9000 species of aves are found
*they are warm blooded animal.
*they have bipeadal feather.
*their fore-limbs are modified into wings.
*the hind limbs are adapted for perching, walking or swimming.
*only preen gland(oil gland) present on tail, and no other gland present on skin.
*Ostrich and parrot lack oil glands
*upper and lower jaws modified into beak,which lack teeth
*legs bear horny epidermal skin.
*respiration occurs in lungs.
*syrinx produces voice in birds not larynx.
*heart is four chambered, sinus venosus is absent.
*renal portal system is very much reduced.
*kidney is metanephric, which directly drain uric acid into cloca through ureter. urinary bladder is absent
*Reha americana (South American Ostrich ) is the only bird which has urinary bladder.
*cerebrum, cerebellum and optic lobes are developed organ of brain.
*birds have 12 pair of cranial nerves.
*bones are pneumatic,means they have air cavity to reduce weight , which helps in flying.
*skull is monocondylic.
*female has well developed single left ovary and oviduct.if right ovary and oviduct are present then they are non-functional.
*sexual dimorphism is found in many birds.
*fertilization is internal
*birds are oviparous, means they lay eggs.
*e.g.-Ostrich, Kiwi. Penguins, Parrot, Duck

OSTRICH

KIWI

PENGUINS

REPTILIA CLASS, VERTEBRATA

*they are about 6000 species
*reptilia are creeping and burrowing cold blooded animals.
*they bear scales
*skin is dry, rough and without scales.
*respiration is by lungs.
*skull is monocondylic.
*except in snake there are two pair of pentadactyl limbs, each with 5 digits bearing claws.
*heart bear two auricles and partly divided ventricles
*kidneys are metanephric
*12 pairs of cranial nerves are present
*ear consists of three parts- internal, middle anr wxternal.
*snake do not possess ear.
*all reptiles are carnivorous/insectivorous, only tortoise feed entirely on vegetation.
*a typical cloaca is present.
*fertilization is internal
*e.g-Chelone(turtle), Testudo(tortoise), Chameleon(tree lizard),Naja(cobra),Bangarus(karait) etc

TESTUDO

CHELONE

NAJA

AMPHIBIA CLASS, VERTEBRATA

*It includes 3000 species.
*they are first evolved cold blooded land living animals.
*they can live on both land and water
*glands present on skin which keep it moist.
*two pairs of limbs for locomotion.
*skull is dicondylic.
*respiratory organs are lungs,buccopharyngeal cavity , skin and gills.
*heart are three chambered.
*kidneys are mesonephric.
*ear consists of internal and middle ear.
*10 pairs of cranial nerves are present.
*they breed in water.
*e.g.-Bufo (toad), Rana (frog),Hyla(tree frog), Salamandra (salamander), Ichthyophis(limbless amphibia).

BUFO

RANA

HYLA

SALAMANDRA

OSTEICHTHYES CLASS, VERTEBRATA

* habitat-both marine and fresh water fishes
* endoskeleton is cartilaginous in the embryonic stage, but in the adult forms it is replaced by bones.
*they are ectothermic( cold blooded)
* there body is streamlined
*the mouth is terminal, digestive tract leads into an anus.
*a swim bladder is usually present,helps in floating
*they have four pair of gills which are covered by an operculum
*the exoskeleton, if present comprises cycloid, ctenoid and ganoid scales.
*the heart is 2- chambered and has sinus venous and anteriosus.
* lung fishes have three chambered heart.
*kidneys are mesonephric.
*there are 10 pairs of cranial nerves.
*fertilization is generally external.
*e.g.- Labeo(rohu), Catla (katla), Muraena(eel)

CHONDRICHTHYES CLASS, VERTEBRATA

*they are marine animals with streamlined body.
*they have cartilaginous endoskeleton
*mouth is located ventrally
*notochord is persistent throughout life
*gills slit are separate and without operculum(gills cover)
*skin is tough and have placoid scales
*teeth are modified placoid,and very strong jaws
*they lack air bladder, hence the have to swim constantly
*heart is two chambered
*some of them have electric organ
*some possess poison sting
*they are cold blooded.
*sexes are separate
*fertilization is internal

*e.g.-Scoliodon, Prestis,Trygon

CYCLOSTOMATA CLASS, VERTEBRATA

*habitat- fresh water and marine water.
*mouth is jawless and they are called jawless fishes.
*body is eel like and tail is compressed
*skin is soft and scale less
*head and brain is poorly developed
*unpaired fins are present
*paired fins and associated girdles are absent
*endoskeleton is cartilaginous
*stomach is absent.
*respiratory organs are gills
*heart is two chambered
*there are 10 or 8 pairs of cranial nerves
*lateral line sense organs are present
*fertilization is external.
*they are mostly parasite on some fishes
*e.g.-Lamprey, Hag fish

CHORDATA PHYLUM

*presence of eal gilnotochord, dorsal hollow nerve cord and paired pharyngeal gill slit are the characterised feature of chotdata.
*habitat- found everywhere
*symmetry- bilateral
*body form- triploblastic
*body cavity- coetomate
*level of organisation-organ system level
*circulatory system- closed type
* phylum chordata is divided into three subphylua-

1. Urochordata /Tunicata
2. Cephalochordata
3. Vertebrata 

*Urochordata and Cephalochordata are comes under protochordates.
*protochordates are exclusively  marine.
*in urochordata the notochord is present only in larval tail.
*in cephalochordata , notochord  extends from head to tail region, throughout life
*e.g.-Urochordata-Ascidia, Salpa,Doliolum
         Cephalochordata-Branchiostoma
*in vertibrata the notochord is replaced by a cartilaginous or bony vertebral column. thus all vertibrates are chordates but all chordates are not vertebrates.

ASCIDIA

BRANCHIOSTOMA