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PREPARED AND PRESENTED BY:

PREPARED AND PRESENTED BY:. SADIA KHURSHID LECTURER, ZOOLOGY DEPARTMENT D.A COLLEGE FOR WOMEN, PHASE V111. VERTEBRATA. General Characters and Super Class Pisces. OUTLINE. Defination General characters Agnatha Cyclostomata Gnathostomata Pisces

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PREPARED AND PRESENTED BY:

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  1. PREPARED AND PRESENTED BY: SADIA KHURSHID LECTURER, ZOOLOGY DEPARTMENT D.A COLLEGE FOR WOMEN, PHASE V111

  2. VERTEBRATA General Characters and Super Class Pisces

  3. OUTLINE • Defination • General characters • Agnatha • Cyclostomata • Gnathostomata • Pisces • Chondrichthyes • Osteichthyes • Dipnoi

  4. VERTEBRATES Vertebrates belong to group craniata. Their name is derived from the presence of serially arranged vertebrae which comprises a major part of their axial endoskeleton, the vertebral column or the back bone. (L.vertebratus, backbone)

  5. CRANIATA Vertebrata are also known as Craniata. Craniata includes chordates having skull, brain box, or cranium enclosing their brain, eyes, inner ear, etc. They are aquatic or terrestrial, usually large sized higher chordates or vertebrates with distinct head and a vertebral column.

  6. GENERAL CHARACTERISTICS OF VERTEBRATES • They posses three fundamental characteristics of chordates i.e. notochord, nerve cord and gill slits. • Lower vertebrates are aquatic and higher vertebrates are predominantly terrestrial. • Body medium to large, bilaterally symmetrical and metamerically segmented. • General body plan consisting of head, trunk, 2 pairs of appendages, and postanal tail.

  7. INTEGUMENT,MUSCLES & DIGESTIVE SYSTEM • Integument of two divisions, including an outer epidermis and an inner dermis; integument often modified to produce hair, scales, feathers, glands, horn, etc. • Muscular, perforated pharynx; this structure is the site of gills in fishes but is much reduced in adult land-dwelling forms.Pharyngeal gill slits not more than 7 pairs. Except in cyclostomes. • Movements provided by muscles attached to endoskeleton of bones and cartilage. • Digestive system is more or less convoluted, with large digestive glands, liver, and pancreas.

  8. SKIN OF VERTEBRATES

  9. RESPIRATION & CIRCULATORY SYSTEM • Respiration in lower aquatic forms by paired gills, in terrestrial forms by lungs. • Blood with red blood corpuscles containing hemoglobin, and in addition, white corpuscles. Blood vascular system is closed type. Heart is ventral, muscular of 2, 3, or 4 chambers.

  10. EXCRETORY, SENSORY & REPRODUCTIVE SYSTEM • Special sensory organs include a pair of eyes and a pair of auditory organ. • Well developed body cavity (coelom) containing visceral systems. • Paired kidneys with ducts to drain waste to exterior. • Most vertebrates with two sexes, each with paired gonads (there are some exceptions) • Development is direct or indirect.

  11. CLASSIFICATION OF VERTEBRATES The vertebrates are subdivided into two sub-phyla: Sub- phylum: Agnatha (jawless vertebrates) Sub-phylum: Gnathostomata( jawed vertebrates)

  12. 1-SUB-PHYLUM AGNATHA They are also known as jaw less vertebrates. Lampreys and hagfishes are the only jawless vertebrates to survive today. They both have a round mouth and for this reason are often referred to as cyclostomes. They are the most primitive type of the vertebrates. By "primitive", a biologist means that they are the least changed from the first vertebrates. They are also known as jawless fishes. They superficially resemble the fishes.

  13. MORE ABOUT AGNATHA Besides lacking jaws, • They have no paired pectoral (shoulder) or pelvic (hip) fins. Median fin with cartilaginous fin rays are present. (FIGURE1& 2) • Their notochord persists for life, never being completely replaced by a backbone even in the lampreys. Endoskeleton is cartilaginous. • They have no scales but unicellular mucous gland is present. • Trunk and tail muscles segmented into myotomes.

  14. AXON, MOUTH AND REPRODUCTION: • The axons of their neurons are unmyelinated (like those of all invertebrates). • Both are parasites.(FIGURE-3) • They have rounded , ventral and suctorial mouth with many rings of teeth.(FIGURE-4) • Sexes separate or united. Fertilization is external. Development is direct or indirect.

  15. DIFFERENT TYPES OF AGNATHA FIGURE-1 A Hagfish FIGURE-2 A Lamprey FIGURE-3 A LAMPREY SUCKS THE BLOOD OF A FISH. FIGURE-4 ORAL VIEWOF LAMPREY SHOWS MANY ROWS OF TEETH.

  16. 2-SUB-PHYLUM GNATHOSTOMATA All the members of this group have: • Both upper and lower jaw. • Teeth may be present or absent. • Myelin sheaths around the axons of their neurons. This permits much more rapid transmission of nerve impulses — a trait probably as important for active vertebrates as their jaws.

  17. DIVISION OF GNATHOSTOMATA This sub-phylum is sub divided into two super classes. 1-Super class Pisces 2- Super class Tetrapoda

  18. 1-SUPER CLASS PISCES This is the largest group of chordates which includes about 25000 species of fishes. Study of fishes is calledichthyology. Super class Pisces is divided into two classes: • 1-Chondrichthyes • 2-Osteichthyes

  19. CHONDRICHTHYES The group, which today is made up of some 800 species of • sharks • skates • rays • They are also known as elasmobranchi. • They are mostly marine. • Shape is usually dorsoventrally flattened. • Caudal fin is heterocercal. • Pelvic fin is usually posterior. In male form claspers for transferring sperms.

  20. MOUTH,GILL SLITS,CLOACA, SCALES & ENDOSKELETON • Mouth is ventral, large and cresentic.(FIGURE-5) • Usually 5 pairs of naked gill slits, no operculum. • 1st gill slit becomes spiracles which open just behind eyes. • Cloacal opening present between two pelvic fins. • Placoid scale forms the exoskeleton. • Endoskeleton is cartilaginous.

  21. PLACOID SCALE

  22. CARTILAGENOUS AND BONY FISHES FIGURE-6 A CLOWN FISH FIGURE-5 A SHARK

  23. DIGESTIVE ,REPRODUCTIVE & NERVOUS SYSTEM • Stomach is j-shaped. • Intestine is short with internal fold or scroll valve in lumen. • Liver has 2 lobes. • Air bladder is absent. • Brain is primitive with large olfactory lobes. • Fertilization is internal. In Pakistan: • Scoliodon called as dog fish is a small shark which is common in our seas.

  24. OSTEICHTHYES As their name indicates, the skeleton in this group is made of bone. This group includes • Sea horse • Flying fish • Globe fish • They are also known as teleostomi. • They are both marine and fresh water forms. • Shape is usually bilaterally flattened. • Caudal fin is homocercal or diphycercal. • Pelvic fin is usually anterior, sometime posterior. Claspers are absent. Whenever present not form by pelvic fins. • Mouth is terminal on head. Variable in shape and size.(FIGURE-6)

  25. GILLSLITS,CLOACA,SCALES,ENDOSKELETON,DIGESTIVE & REPRODUCTIVE SYSTEM • Usually 5 pairs of gill slits covered by a lateral flap of skin called operculum, so that a single gill opening on either side. • Spiracles are lacking. • Cloaca is absent. Anus and urinary and genital aperture open separately. • Ctenoid and cycloid scale forms the exoskeleton. • Endoskeleton is bony. • Stomach shape is variable and absent in some. • Intestine is long and without internal fold or scroll valve in lumen. • Liver has 3 lobes. • Air bladder is present. • Brain is advanced with small olfactory lobes. • Fertilization is external

  26. CYCLOID AND CTENOID SCALE

  27. ANATOMY OF BONY FISH

  28. DIAGRAM OF FISH GILLS

  29. NUMBER OF SPECIES: This group of osteicththyes includes26000 species. • Eel • Sea horse • Flying fish etc. • In Pakistan: Perches(Pomfret) ,hilsa(Pallah), carps(Rohu)), mackerel(Surmai) ,Cat fish(Khagga) and Salmon(Trout) are edible fishes of Pakistan.

  30. DIPNOI (LUNG FISHES) • LUNG FISHES belonging to the order Dipnoi are included in class Osteichthyes. • The Dipnoi are a group of sarcopterygiian fish, are commonly known as the lungfish. Their "lung" is a modified swim bladder, which in most fish is used for buoyancy in swimming, but in the lungfish also absorbs oxygen and removes wastes. • Modern lungfish in Africa and South America are able to survive when their pools dry up by burrowing into the mud and sealing themselves within a mucous-lined burrow. During this time, they breathe air through their swim bladder instead of through their gills, and reduce their metabolic rate dramatically. These fish will even drown if they are kept underwater and not allowed to breathe air!

  31. South American Lungfish : Here's (FIGURE-7) a living species of Lepidosiren. If you look carefully, you can see the four slender "fins" of this fish, which are homologous to the four legs of terrestrial vertebrates. • There are only three genera of lungfish alive today. • Neoceratodus (Australian lung fish) • Leipdosiren (South American lung fish) • Protopterus (African lung fish) Africa. • The largest of these is the Australian species, which may grow to as long as 1.8 meters. FIGURE-7 South American Lungfish

  32. REFERENCES • WEBSITE USED: • www.wikipedia.com • www.youtube.com • www.google.com • www.glossary.com • www.answer.com • BOOKS: • Elements of Chordate Anatomy by Charles K. Weichert • Modern Text Book of Zoology, Vertebrates. R.L. Kotpal

  33. THANK YOU

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