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Yeshwantrao Chavan Mahavidyalaya , Tuljapur , Dist.-Osmanabad-413 601 (MH), INDIA. Department of Fishery Science. Dr S L Bhalkare Head and Assistant prof. B.Sc. First Year Semester I Paper I Topic: General Chas.of Fishes. Characteristics of Fishes. Class: Agnatha. Jawless fish
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YeshwantraoChavanMahavidyalaya, Tuljapur, Dist.-Osmanabad-413 601 (MH), INDIA Department of Fishery Science Dr S L Bhalkare Head and Assistant prof.
B.Sc. First Year Semester I Paper I Topic: General Chas.of Fishes
Class: Agnatha • Jawless fish • Round, tube-like bodies covered with slimy skin • No scales, bodies made of cartilage • Ex. Lampreys, Hagfish, etc.
Class: Condrichthyes • Cartilaginous fish • Moveable jaws and scales present • Ex. Sharks, Skates and Rays
Class: Osteichthyes • Bony Fish • Skeletons made of hard bone • Scales and a swim bladder present • 95% of ALL fish belong to this class
Pyloriccecum Esophagus Stomach Kidney Brain Swimbladder Vertebra Gills Spinalcord Muscle Mouth Operculum Heart Anus Urinarybladder Reproductiveorgan Pancreas Gallbladder Intestine Liver Anatomy of a Fish
Fish Circulation • Fish have gills that absorb O2 from the water, and release CO2 • Fish have a simple, two-chambered heart
Gill Structure & Function • Gills act as a counter current gas exchanger.
Countercurrent Exchange O2 Concentration
Fish Adaptations • Some fish have remained unchanged for millions of years • Ex. Coelacanth • Some fish are able to “walk” on land, and can survive for long periods of time without water • Ex. Lungfish
Fish Adaptations • Many fish function as a top predator in their ecosystem • Ex. Great Barracuda, Arowana
Fish Adaptations • Many fish are adapted to survive conditions in the deep ocean • lack of sunlight • extreme pressures • Ex. Angler Fish