Property
1) Nerve Cord - single, dorsal, hollow. Differentiates brain and spinal cord
2) Notochord - dorsal, supporting endoskeleton
3) Post anal tail for balancing
4) Heart - ventral
5) Paired pharyngeal gill slits
Habitat
Aquatic or terrestrial
LOO
Organ system
BP
Tube within tube
Symmetry
Bilateral symmetry
GL
Triploblastic
Coelom
Eucoelomate
Metamerism
Notochord
Yes
Yes
PHYLUM CHORDATA IS DIVIDED INTO
1) GROUP ACRANIATA / PROTOCHORDATA
–) Sub phylum Urochordate
–) Sub phylum Cephalochordate
2) GROUP CRANIATA / EUCHORDATE
–) Sub phylum Vertebrata
A) Division Agnathostome Agnatha
I
\+) Class Cyclostome
B) Division Gnathostomes
I
a) Super class PISCES
I
• Class Chondrichthyes
• Class Osticichthyes
b) Super class Tetraioda
•Amphibia
•Reptilia
•Aves
• MammalsGROUP PROTOCHORDATE (primitive) / ACRANIATA (absence of cranium)
(Exclusively marine)
SUB PHYLUM UROCHORDATE
• Notochord is present only in tail of larva, -nt in adults.
• Commonly ka TUNICATES. Body is covered with cellular like sheath called TUNICIN
• EXAMPLES - Ascudia, Salpa, Doliolum
________________________________________
SUB PHYLUM CEPHALOCHORDATE
• Notochord +nt from head to tail through out its life
• EXAMPLES - Branchiostoma / Amphioxus (Lancelet)
GROUP EUCHORDATE (true) / CRANIATA (cranium present)
SUBPHYLUM VERTEBRATA
• Notochord replaced by vertebral column
• Gills or lungs for respiration
• Muscular heart which could be 2/3/4 chambered
• Kidneys for excretion
• Gonads present. Ovary for females. Testis for males.
• All vertebrates are chordates but all chordates are not vertebrates
• Divided into division Agnathostome and division Gnathostome
DIVISION AGNATHOSTOME
(Absence of jaws and mouth)
1) Mouth not bounded by jaw
CLASS CYCLOSTOME (circular mouth)
• All are aquatic. Both marine and freshwater
• Circular, succtorial mouth without any jaws
• They are ectoparasites on some fishes
• 6-15 pair of gill slits +nt
• Endoskeleton, cranium and vertebral column is cartilaginous
• They are marine water but for spawning (to lay eggs and sperm) , they migrated to fresh water. After spawning, adult dies. Sperm and egg forms zygote
• the larva which grows into adult, migrate back to marine water
• They don’t have scales and paired fins
• EXAMPLES -
1) Petromyzon (lamprey)
2) Myxine (Hagfish)
DIVISION GNATHOSTOME (jaws and mouth present)
1) mouth bounded by jaws
SUPER CLASS PISCES
• all aquatic
• scales +nt
• paired or unpaired fins present
• gills for respiration
• 2 chambered heart
• nictitating membrane covering the eye to protect underwater present
• dorsal fin, anal fin, pectoral fins (2), caudal fin, pelvic fin (2)
• All fishes (pisces) are poikilotherms (cold blooded)
• Divided into Class Chondrichthyes and Class Osticichthyes
CLASS CHONDRICHTHYES
• marine water
• cartilagenous endoskeleton. hence known as CARTILAGINOUS FISH
• NOTOCHORD persist through out life
• they have PLACOID SCALES and backwardly directed teeth, ie modified PLACOID SCALES
• mouth is ventral
• Operculum (gill cover) is absent
• Swim bladder/air bladder is -nt. So they need to constantly swim to avoid sinking
• Caudal fin is heterocercal
• internal fertilization
• viviparous (directly give birth to young)
• male bears copulatory structures known as claspers on pelvic fin to hold female body
• Usually predatious with poisoning sting, electric organs
CLASS OSTEICHYTHYES
• marine + freshwater
• endoskeleton bony. Hence ka BONY FISHES
• NOTOCHORD replaced by vertebral column
• they have CYCLOID and CTENOID scales
• mouth is terminal
• 4 pair gills covered by Operculum
• swim bladder (that provides buoyancy) is +nt. Hence don’t need constant swimming effort
• Caudal fin is homocercal
• external fertilization
• oviparous (egg laying)
• direct development
EXAMPLES OF CHONDRICHTHYES
1) Pristis (saw fish)
2) Torpedo (electric ray)
3) Trygon (sting ray)
4) Carcharodon (great white shark)
5) Scolidon (dog fish)
EXAMPLES OF OSTEICHYTHYES
FRESH WATER
1) Labeo (Rohu)
2) Clarius (Magur)
3) Catla (katla)
AQUATIC
1) Betta (fighting fish)
2) Pterophyllum (angel fish)
MARINE WATER
1) Exocoetus (flying fish)
2) Hippocampus (sea horse)
Male bears brood pouch (takes care of embryo)
SUPERCLASS TETRAPODA
Appendages (limbs/wings)
CLASS AMPHIBIA
• dual life (terrestrial and water)
• body divisible into head and trunk
• some may have tails - Salamader
• nictitating membrane covering eye
• cloaca present (common chamber for alimentary, excretion, reproduction and canal opening)
• tympanum representing external ear
• skin without scales. Moist, smooth and glandular
• dicondylic skull
• skin , gills and bucco pharynx lungs for respiration
• incomplete double circulation. 3 chambered heart
• poikilotherms
• excretion via kidney
• excretory product - aquatic NH3, Terrestrial Urea
• frtlztn - external . Development - indirect
• oviparous
CLASS AMPHIBIA EXAMPLES
1) Hyla (tree frog)
2) Rana (frog)
3) Bufo (Toad)
4) Salamandra (salamander)
5) Icthyophis (limbless amphibia)
CLASS REPTILIA
• creeping and crawling animals
• 1st true land vertebrate
• cloaca and tympanum present
• external ear opening absent
• dry skin. Has epidermal scales/scutes • scales often shed - ecdysis or molting
• monocodylic skull
• respiration through lungs
• incomplete double circulation. 3 chambered heart except for crocodile and alligator (4 chambered)
• excretion via kidney
• excretory product is uric acid
• internal fertilization, direct development
• oviparous
• poikilotherms
EXAMPLES OF CLASS REPTILIA
1) Hemidactylus (wall lizard)
2) Chameleon (tree lizard)
3) Calotes (garden lizard)
4) Chelone (turtle)
5) Testudo (tortoise)
6) Crocodilus (crocodile)
POISONOUS SNAKES
7) Naja (cobra)
8) Bangrus (krait)
9) Vipera (viper)
