The outer most cells on the skin surface are thin,dead and fully keratinised. They form a horny or cornified layer called stratum corneum. It is especially thick on soles and palms.The outer portion of this layer is constantly being worn away,the dandruff is a familiar .News cells are constantly added from when the granular cells become horny and die. This dead layer is tough ,prevents mechanical injuries and fungal and bacterial attacka,and reduces water loss from the body. The outer surface of epidermis contains minute openings of sweat glands and hair follicles.
Wednesday, 30 May 2012
Tuesday, 29 May 2012
TETRODON,DIODON,OSTRACION
Family tetrodontidae,order tetraodontiformes.commonly called globe fish or puffer.shape round or globose when taken out the water,it inflates suddenly with air like a balloon and a sound is emitted by forceful expulsion of air fromoesophagus. scales modified into small spines,especially on ventral side. mouth narrow,teeth fused to form beak.eyes large and protruding pelvic fins lacking.it contain alkaloid poisoncalled tetrodotoxin which is used in lung infection in japan.
DIODON-Family diodontidae,order tetraodontiformes. commonly called porcupine fish. occurs from red sea through indian seas to pacific ocean.Body uniformly covered by large movable spines for defence.
OSTRACION-FAMILYostraciontidae,order tetraodontiformes.Body roughly triangular and encased in a carapace or armour of hexagonal bony plates.commonly called trunk fish or coffer fish.due to presence of two horn like suptaorbitalspines called as cow fish.
DIODON-Family diodontidae,order tetraodontiformes. commonly called porcupine fish. occurs from red sea through indian seas to pacific ocean.Body uniformly covered by large movable spines for defence.
OSTRACION-FAMILYostraciontidae,order tetraodontiformes.Body roughly triangular and encased in a carapace or armour of hexagonal bony plates.commonly called trunk fish or coffer fish.due to presence of two horn like suptaorbitalspines called as cow fish.
STRUCTURE OF SKIN-RABBIT
The skin of rabbit is also built of two main parts -an outer epidermis and an inner dermis.
EPIDERMIS-It is the outer thin stratified epithelium developed from the embryonic ectoderm.The epidermis consist of malpighian layer and the superficial cornified layer.
(a)MALPIGHIAN LAYER-The malpighian layer,or stratum malpighii is divided into (1)SRRATUM GERMINATIVUM-The germinal layer is the innermost layer in contact with the basement membrane secreatedby the underlying dermis.Its cells are columnar,arranged in a single row one cell thick,and continually divide mitotically adding new cells to the epidermis
.
STRATUM SPINOSUM-Its lies above the germinal layer and is also called the transitional layer. It is several layer thick and made of polyhedral cells.these cells are gradually pushed outwards,they become flattened and keratinized due to deposition of a horny scleroprotein known as keratin.
STRARUM GRANULOSUM-The cells in the upper part of stratum spinosum form the granular layer containing keratohyalin granules. It is developed in parts of the body having thick epidermis such nas the palms and the soles.
STRATUM LUCIDUM-Above granular layer in palms ther is non-stainable layer of shiny and refracitle cells.
EPIDERMIS-It is the outer thin stratified epithelium developed from the embryonic ectoderm.The epidermis consist of malpighian layer and the superficial cornified layer.
(a)MALPIGHIAN LAYER-The malpighian layer,or stratum malpighii is divided into (1)SRRATUM GERMINATIVUM-The germinal layer is the innermost layer in contact with the basement membrane secreatedby the underlying dermis.Its cells are columnar,arranged in a single row one cell thick,and continually divide mitotically adding new cells to the epidermis
.
STRATUM SPINOSUM-Its lies above the germinal layer and is also called the transitional layer. It is several layer thick and made of polyhedral cells.these cells are gradually pushed outwards,they become flattened and keratinized due to deposition of a horny scleroprotein known as keratin.
STRARUM GRANULOSUM-The cells in the upper part of stratum spinosum form the granular layer containing keratohyalin granules. It is developed in parts of the body having thick epidermis such nas the palms and the soles.
STRATUM LUCIDUM-Above granular layer in palms ther is non-stainable layer of shiny and refracitle cells.
Monday, 28 May 2012
HEMIRHAMPHUS,ANABAS,REMORA
Family hemirhamphidae, order beloniformes. found in river and ponds of w.bengal and orissa. called as haif-beaked fish.lower dentaries projected beyond the upper jaw,both having pointed teeth.
ANABAS-family Anabantidae ,order perciformes.accessory respiratory organs of thin laminae in supra-branchial chambers,for breathing atmospheric air.travel on land by fins and opercular spines.
REMORA-Family echeneidae, order echeneiformes.size up to 50 cm.scales minute,head depressed and its upper surface bears a large,flat,oval adhesive discor sucker made by two rows of transverse lamillae.scales modified anterior fin. fish usually carried from place to place attached to body of largefish.naive captures sea turtles and fishes with a remora tied with a cord.remora eats smaller fishes.
ANABAS-family Anabantidae ,order perciformes.accessory respiratory organs of thin laminae in supra-branchial chambers,for breathing atmospheric air.travel on land by fins and opercular spines.
REMORA-Family echeneidae, order echeneiformes.size up to 50 cm.scales minute,head depressed and its upper surface bears a large,flat,oval adhesive discor sucker made by two rows of transverse lamillae.scales modified anterior fin. fish usually carried from place to place attached to body of largefish.naive captures sea turtles and fishes with a remora tied with a cord.remora eats smaller fishes.
Saturday, 26 May 2012
HIPPOCAMPUS,SYNGNATHUS,FISTULARIA
Belongs to family syngnathidae, order syngnathiformes.Size 5 to 20 cm. Found in tropical and temperate seas including Indian ocean commonly called sea-horse.
BODY- Head large at right angle,tubular snout,mouth toothless and suctorial. Tailed long ,prehensil and coiled around sea-weeds, gills lophobranchs made of several small rounded lobes.On the belly of male is a brood pouch for incubating eggs. On the belly of female is a small anal fin.
SYNGNATHUS- family syngnathidae,order syngnathiformes.45 cm long.structures and habits similar to those of Hippocampus,except that is non-prehensile and carries a small caudal fin,COMMONLY CALLED PIPE FISH.
FISTULARIA-. COMMONLY CALLED FLUTE FISH because of slender elongated eel -like body and long tubular snout.skin naked. mouth small,narrow with minute teeth.caudal fin present with middle caudal ray much elongated and supported by horny rays.
BODY- Head large at right angle,tubular snout,mouth toothless and suctorial. Tailed long ,prehensil and coiled around sea-weeds, gills lophobranchs made of several small rounded lobes.On the belly of male is a brood pouch for incubating eggs. On the belly of female is a small anal fin.
SYNGNATHUS- family syngnathidae,order syngnathiformes.45 cm long.structures and habits similar to those of Hippocampus,except that is non-prehensile and carries a small caudal fin,COMMONLY CALLED PIPE FISH.
FISTULARIA-. COMMONLY CALLED FLUTE FISH because of slender elongated eel -like body and long tubular snout.skin naked. mouth small,narrow with minute teeth.caudal fin present with middle caudal ray much elongated and supported by horny rays.
AMIA
The single species of bowfin, amiacalva, is another large,powerful,predatory freaswater fish of north america. The head skeleton and scales are simplifedAND TAIL IS ALMOST HOMOCERCAL. It moves by undulation of body and the long dorsal fin.
Friday, 25 May 2012
POLYODON
Paddle fishes or spoonbills are large bizarre fishes with an intriguing. The great elongation of snout into a flat oar-like rostrum. It is used to strir food from muddy river bottom,paddle fishes are planktivores.
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