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| Phylum Chordata |
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| This phylum is characterized by three unique features, at least during the early stages of their development. |
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 A rod like structure called notochord lying above the digestive tract. |
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 A tubular nerve cord lying above the notochord. |
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 A pair of gill slits in the pharangeal region. |
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| Only the nerve cord persists throughout the life of the organism. The notochord is usually replaced by a vertebral column and the gill slits disappear during the embryonic stage. Phyllum chordata is divided into three subphyla |
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 Sub phylum urochordata. |
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 Sub phylum cephalochordata. |
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| Pyrosoma |
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 Marine in habitat. |
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 Notochord is found in the tail in the larval form. Hollow nerve cord is also present in the larva. |
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 Body is covered by a tunic. |
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 Phyarynx has several gill slits. |
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| Example: |
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| Herdmania, Doliolum, Pyrosoma |
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| Brachiostoma |
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 Headless, tiny fish-like chordates. |
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 Notochord, nerve cord without a distinct brain, gill slits and a port anal tail present. |
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| Example: |
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| Branchiostoma (Amphioxus) |
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 This includes the majority of chordates. |
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 Head is prominent. |
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 Nervous system and exoskeleton are highly developed. |
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 Notochord is replaced by a jointed vertebral column. |
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 Two pairs of appendages (limbs). |
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 Aquatic animals have gills. |
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| Subphylum vertebrata is sub divided into seven classes |
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 Cyclostomata |
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 Chondrichthyes |
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 Osteichthyes |
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 Amphibia |
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 Reptilia |
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 Aves |
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 Mammalia |
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| Petromyzon (lamprey) |
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 Very primitive vertebrates. |
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 Do not have jaws. Being ectoparasites, mouth is of the sucking type with the help of which they stick to the host. |
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 Notochord present. |
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 Respiration is by gills enclosed in pouches. |
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 Heart has two chambers. |
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 Is cold blooded. |
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 Gonad is single and fertilization is external. |
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| Example: |
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| Petromyzon (Lamprey) |
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| Scoliodon |
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 Large marine organisms. |
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 Body is flat, disc shaped or spindle shaped. |
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 Body is covered with placoid scales. |
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 Skeleton is cartilaginous. |
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 Respiration is through gills. |
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 Heart is two chambered. |
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| Example: |
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| Scoliodon (Indian shark), Torpedo (electric ray), Trygon (sting ray) |
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| Labeo rohita (rohu) |
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 Found in lakes, rivers and seas. |
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 Spindle shaped body covered with cycloid or tenoid scales. |
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 Mouth is anterior. |
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 Skeleton is partly or completely bony. |
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 Gills are filamentous. |
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 Heart is two chambered. |
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| Example: |
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| Labeo (carp), Exocoetus (flying fish), Hippocampus (sea horse), |
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| Anabas (climbing perch), Protopterus (lung fish) |
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| Dendrobates |
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 Live in both water and on land. |
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 Respiration is by gills, lungs or skin. |
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 3 chambered heart. |
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 Is cold blooded. |
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 Have two pairs of pentadactyl (5 digit) limbs which may be absent in some cases. |
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| Example: |
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| Rana (frog), Bufo (toad), Hyla (tree frog), Necturus |
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| Flying lizard (Draco) |
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 Mostly terrestrial. |
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 Heart is 3 chambered, is cold blooded. |
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 Breathe through lungs. |
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 Body covered with scales. |
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 Have two pairs of pentadactyl (five digit) limbs which are absent in snakes. |
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| Example: |
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| Hemidactylus (wall lizard), chameleon, Draco (flying lizard) |
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| Sparrow |
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 Arboreal in habitat i.e, they live on trees. |
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 Warm blooded. 4 chambered heart. |
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 Body covered with feathers. |
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 Lungs have membranous extensions called air sacs to make the body light. |
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 Mouth is surrounded by a beak. Teeth are absent. |
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 Fore-limbs are modified into wings. |
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| Chimpanzee |
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 Most intelligent of all organisms. |
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 Warm blooded with 4 chambered heart. |
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 Give birth to young ones. |
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 The mother suckles her young ones on milk secreted by special glands called mammary glands. |
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 Body covered with hair. |
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 Have two pairs of pentadactyl limbs. |
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 Breathe through lungs. |
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