HEMIRHAMPHUS,DIODON

Family hemirhamphidae,order beloniformes. found in rivers and ponds of w.bengal and orissa,called haif-beaked fish.lower jaw projected beyond the upper jaw,both having pointed teeth.
DIODON-family diodontidae,order tetraodontiformes. similar to tetradon in structures and habit aiso called as porcupine fish. occurs from red sea through out indian seas to pacific ocean.

CLARIAS,HETEROPNEUSTES

Cat fish clarius batrachus  has accessory respiratory organs.These are in the formof two much branched tree-like dendritic or arborescent organs developed inside suprabranchial cavities one on either side above the gill chambers. The cavities and the organs are covered by vascular mucous epithelium and functions as lungs. The fish periodically reaches watter surface to renew air.
HETEROPNEUSTES-This catfish has a pair of long tubular and dorsally situated air sacs arising posteroorly from gill chambers and extending almost up to the tail.They are highly vascular .The air is drawn in and expelled out through pharynx.

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.

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.

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.

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.

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.

OSTEICHTHYES-BONY FISH-latimeria

There are 20,000 living species of bony fish.The teleostei comprising about 17,000 species.
LOBE-FINNED FISH
LATIMERIA-They were dominant in devonian times about 280 million years.Dr.j.l.b smith of rhodes university named this "living fossil" Latimeria chalumnae. Latimer is blue-grey with irregular white spots and highly reflective golden eyes. size range 0.75 to slightly over 2 m.In the absence of claspers male latimeria achieve copulation is not know.It discovered in 1938 coast of south africa,crossopterygians are all extinct .
The skeletal elements of paired fins lobes resembled the priximal skeletal elements of tetrapod limbs.
skull was similar to that of earliest amphibians.
Fresh waters forms migrated from one body of water to another because they could use their air bladders like lungs.

OSTEICHTHYES-SCORPAENIFORMES

Enlarged heads and pectoral fins.
Projecting spines from gill covering.
e.g pterois(scorpion fish)
ORDER 12.PLEURONECTIFORMES
Bottom dwellers.
Body flat, lying one side.
Head asymmetrical ,both eyes present on upper or dorsal side.
Dorsal and anal fins fringing body.e.g
flatfish-pleuronectes,synaptura,solea.
ORDER 13. ECHENEIFORMES
Scales cycloid.
No air bladder.
Dorsal fins form a flat oval adhesive disc.
e,g echeneis or remora(sucker fish)
ORDER 14. TETRAODONTIFORMES OR PLECTOGNATHI
Strong jaws with a sharp beak.
Scales often spiny.
e.g diodon(porcupine fish),tetrodon(globe fish),ostracion(trunk fish)
ORDER 15. LOPHIIFORMES
Bulb like tip over head to lure prey into wide mouth.
luminescent organ present.
e,g antennarius(angler fishes)

OSTEICHTHYES- 5. ORDER BELONIFORMES

Scales cycloid.
Pectoral fins large.
e.g
exocoetus ,cypselurus(flying fish)belone(garfish),hemirhamphus(half beak),belone(garfish).
ORDER 6. SYNGNATHIFORMES OR SOLENICHTHYES
Protective scales on body.
snout tubular with suctorial mouth.
swim bladder closed.
e.g hippocampus(sea horse),syngnathus(pipe fish),fistularia(flute fish)
ORDER 7.OPHIOCEPHALIFORMES OR CHANNIFORMES
Head depressed with plate-like scales.
Air bladder long and without duct.
Accessory respiratory organs present.
e.g ophiocephalus or channa.
ORDER 8. SYMBRANCHIFORMES
Body elongated,e,g eel.
Gill slits join to form ventral slit.
Paired fins,air bladder lacking.
e.g amphipnous,symbranchus(eels).
ORDER 9. MASTACEMBELIFORMES
Body eel-like.
nostrils on tubular tentacles at end of snout. e,g mastacembelus,macrognathus.
ORDER 10.PERCIFORMESOR PERCOMORPHI
Fin spines present.
Dorsal fins weberian apparatus absent.
Air bladder with out duct.e,g lates(bhetki)

OSTEICHTHYES-SUPERORDER-TELEOSTEI

Mouth opening terminal,small.
Scales cycloid,ctenoid or absent.
Tail fin homocercal.
 A hydrostatic swim bladder usually present.
Advanced or modern ray-finned fishes.
ORDER 1. CLUPEIFORMES
Scales cycloid.
Head and operculum not scaled.
Fins without spines.
Tail fin homocercal.
Pelvic finsabdominal.
Air bladder withopen duct to pharynx.
No auditory vesicles.
e.g clupea,salmo sardinops esox notopterus.
ORDER 2. SCOPELIFORMES
Deep sea forms with phosphorescent organs.
Mouth wide with minute teeth.Swim bladder absent. Dorsal and anal fins with claspers.
ORDER 3.CYPRINIFORMES
Air bladder with duct to pharynx. ossicles present between airbladderand internalear.
e.g labeorohita clarius wallago electrophorus.
ORDER  4. ANGUILIIFORMES
Body long and slender,snake-like .
Scales absent.
Dorsal and anal fins long .
Pelvic fins present.
Air bladder .
e.g anguilla muraena(moray)

OSTEICHTHYES-HOLOSTEI

Mouth opening small.
Ganoid or cycloid scales.
Tail fin heterocercal.
Ray-finned fish, transitinal between CHONDROSTEI AND TELEOSTEI.
ORDER 1. AMIIFORMES
Thin, overlapping cycloid scales.
Snout normal ,rounded.
Long dorsal fin.
e.g AMIA(BOWFIN)
ORDER 2. SEMIONOTIFORMES
Scales rhomboidal ganoid in oblique rows.
Snout and body elongated. e.g Lepidosteus or lepisosteus(garpike)

OSTEICHTHYES-SUBCLASS-ACTINOPTERYGII

Paired fins thin,broad, without fleshy basal lobes, and supported by dermal finrays.
One dorsal fin, may be divided.
Caudal fin without epichordal lobe.
Olfactory sacs not connected to mouth cavity.
Popularly called ray- finned fishes. divided into three infraclasses or super orders CHONDROSTEL HOLOSTEI AND TELEOSTEI.
SUPERORDER A. CHONDROSTEI
Mouth opening large.
Scales ganoid.
Tail heterocercal.
e.g ray-finned fish or cartilaginous ganoid.
ORDER 1. POLYPTERIFORES
Rhomboid ganoid scales and pectrol fins.
Dorsal fin of eight finlets.
Ossified skeleton.
e.g polypterus(bichir)
ORDER 2. ACIPENSERIFORMES
Scales less .
Skleton cartilaginous.
e.g acipenser(sturgeon), polyodon(paddlefish)

OSTEICHTHYES-BONY FISH

SUBCLASS-SARCOPTERYGII
Paired fins leg-like with a fleshy,bony central axis covered by scales.
Dorsal fins.
Caudal fin hreterocercal with an epichordal lobe.
Olfactory sacs usually connected to mouth cavity by internal nostrils or choanae.
Fleshy or lobe-finned or air breathing fish.
Divided into two superorders .ORDER 1. CROSSOPTERYGII
Paired fins lobate.
Caudal fin three lobed.
Premaxillae and maxillae present.
Internal nares present or absent.
Spiracles present.
Air bladder vestigial.
Primitive fleshy-finned extinct fishes. Latimeria. ORDER 2. DIPNOI
Median fins continuous to form diphycercal tail.
Premaxillae and maxillae absent.
Internal nares present and spiracles absent.
Air bladder single or paired,lung like e.gEPICERATODUS,PROTOPTERUS LEPIDOSIREN.

OSTEICHTHYES-CLASSIFICATION

It includes true bony fishes.There include 20,000 living species,both freshwater and marine. Some of the freshwater forms are the carp,perch,bass, trout,catfish,sucker. Where as marine fishes are the tarpon,meckerel,tuna,sailfish,barracula,flyingfish. The classification of class osteichthyes by A.S.ROMER(1966) . The two subclass include sarcopterygii and Actionpterygii.The subclass Teleostei include 17,000 species the singke largest group of living vertebrates.

OSTEICHTHYES-BONY FISH

Cloaca lacking.
Anus absent.
Respiration by four pair of gill on bony gill arches, covered by a common operculum on either side.
Ventral heart
Sinus venosus and conus arteriosus present.
Adult kidneys mesonephric.
Excretion ureotelic.
Brain with very small olfactory lobes, small cerebrum and well developed optic lobes and cerebellum.
Cranial nerves 10 pairs.
Well developed lateral line system.
Internal ear with three semicircular canals.
Sexes seperate.
Gonads paired.
 Fertilization usually external.
Mostly oviparous,rarely ovoviviparous or viviparous.
Eggs minute to 12 mm.
Cleavage meroblastic.
Development direct, rarely with metamorphosis.
Claspers absent.

OSTEICHTHYES-BONY FISH

GENERAL CHARACTERS
Inhabit all sorts of water-fresh,brackish or salt warm or cold water.
Body spindle-shaped and streamlined.
Fins both median and paired ,supported by fin rays of cartilage or bone.
Tail usually homocercal.
Skin with mucous gland,usually with embedded dermal scales of 3 types ganoid,cycloid or ctenoid.
Placoid abescent.
Endoskeleton chiefly of bone.
Claspers absent.
Mouth terminal or subterminal.