Seminer.docx

KENDRIYA VIDYALAYA SAMBALPUR

SCIENCE PROJECT SESSION 2016-17 TOPIC- FISHES MADE BY –PUJARANI BEHERA CLASS- IX- C ROLL NO- 16 GUIDED BYS.S.BHOI SIR

PISCES [Fishes] CLASSIFICATION  Kingdom-: Animalia  Phylum-: Chordata  Sub Phylum-: Vertebrata  Classes- : Chondrichthyes and Osteichthyes About fishes A fish is any member of a paraphyletic group of organisms that consist of all gill-bearing aquatic animals that lack limbs with digits. Most fish are ectothermic ("cold-blooded"), allowing their body temperatures to vary as ambient temperatures change, though some of the large active swimmers like white shark and tuna can hold a higher core temperature. There are 24000 different species of are found in the earth. Study of fishes is called “Icthyology”

FISHES ARE DIVIDED INTO TWO TYPES-: 1.Osteichthyes [Bony Fish] 2.Chondrichthyes [Cartilaginous Fish] Osteichthyes [Bony Fish] Bony fish (Scientific name-Osteichthyes) are fish that have a skeleton made of bone. They also have teeth that are fixed into the upper jaw. They have a swim bladder that opens into the gullet. They do not have to swim to push water through the gills. Bony fish are often divided into two groups - the Rayfinned fish which contain most species of fish and the very small group of Lobe-finned fish. The fins of these fish have jointed, bony rays that support them. These fish have large eyes and no internal nostrils. They have a swim bladder that opens into the gullet. Bony fish can be omnivores, carnivores,herbivores or detrivores. The ocean sunfish is the largest bony fish and the longest is the oarfish. Specimens of ocean sunfish have been observed up to 3.3 metres in length and weighing over 2,300 kilograms. E.g- Labeo Rohita and Sea horse.

Chondrichthyes [Cartilaginous Fish]

Cartilaginous fish (scientific nameChondrichthyes) have a skeleton made from cartilage instead of bone.Cartilage is tough and flexible and provides enough structural support to allow these fish to grow to very large sizes. Cartilaginous fish include sharks, rays, skates and chimaeras. There are approximately 600 different species of rays and skates and about 500 shark species. Rays and skates live in oceans throughout the world. Most rays and skates live on the bottom of the ocean while Some live in open water. Some rays also live in freshwater. The manta ray (Manta birostris) feeds on plankton and small fish is the largest ray reaching up to 9 metres in width and can weigh several tonnes. The mouth, nostrils and gill slits of skates and rays are always found on the underside of the fish, with the eyes and spiracles on the upper side. Many species also have spines and thorns on the upper surface and tail. Like sharks, it is easy to distinguish mature males as they have a pair of claspers beneath the pelvic fins. These are absent in females.

SOME AMAZING FACTS ON FISHES

1. Most fish reproduce by laying eggs, though some fish, such as great white sharks, give birth to live babies called pups. 2. The largest fish is the great whale shark which can reach fifty feet in length. 3. The smallest fish is the Philippine goby that is less than 1/3 of an inch when fully grown. 4. Starfish are not fish. Neither are jellyfish. 5. Catfish have over 27,000 taste buds. Humans have around 7,000. 6. Sharks are the only fish that have eyelids. 7. Most fish have taste buds all over their body. 8. The fastest fish is the sailfish. It can swim as fast as a car travels on the highway. 9. Anableps, four-eyed fish, can see above and below water at the same time. 10. A seahorse can move each of its eyes separately. One eye can look forward while the other looks backward. Seahorses can also change their color to match their surroundings. …….. THE END………

DIFFERENCE BETWEEN BONY FISH AND CARTILAGINOUS FISH BONY FISH

CARTILAGINOUS FISH

Bony endoskeleton.

Cartilaginous endoskeleton.

Four pairs of gills 5-7 pairs of gills slits slits occur. These are are present and covered by operculum is absent. operculum. Mouth is terminal in position.

Mouth is ventral in position.

Caudal fin is homocercal.

Caudal fin is heterocercal.

Air or swim bladder is usually present.

Air or swim bladder is absent.

E.g- Labeo Rohita and Sea horse.

E.g- Scoliodon and Torpedo.