2 Fish Anatomy PDF
Preview 2 Fish Anatomy
Revised Edition: 2016 ISBN 978-1-283-49304-8 © All rights reserved. Published by: Research World 48 West 48 Street, Suite 1116, New York, NY 10036, United States Email: [email protected] Table of Contents Chapter 1 - Diversity of Fish Chapter 2 - Fish Anatomy Chapter 3 - Decline in Amphibian Populations Chapter 4 - Evolution of Birds Chapter 5 - Bird Anatomy Chapter 6 - Evolution of Reptiles Chapter 7 - Evolution of Mammals WT Chapter 8 - Primate Cognition Chapter 9 - Animal Testing on Non-Human Primates ________________________WORLD TECHNOLOGIES________________________ Chapter- 1 Diversity of Fish WT Fish come in many shapes and sizes. This is a sea dragon, a close relative of the seahorse. They are camouflaged to look like floating seaweed. Fish are very diverse and are categorized in many ways. Although most fish species have probably been discovered and described, about 250 new ones are still discovered every year. According to FishBase, 31,500 species of fish had been described by January 2010. That is more than the combined total of all other vertebrates: mammals, amphibians, reptiles and birds. ________________________WORLD TECHNOLOGIES________________________ By species Fish systematics is the formal description and organisation of fish taxa into systems. It is complex and still evolving. Controversies over "arcane, but important, details of classification are still quietly raging." The term "fish" describes any non-tetrapod chordate, (i.e., an animal with a backbone), that has gills throughout life and has limbs, if any, in the shape of fins. Unlike groupings such as birds or mammals, fish are not a single clade but a paraphyletic collection of taxa, including jawless, cartilaginous and skeletal types. Jawless fish Jawless fish are the most primitive fish. There is current debate over whether these are really fish at all. They have no jaw, no scales, no paired fins, and no bony skeleton. Their skin is smooth and soft to the touch, and they are very flexible. Instead of a jaw, they possess an oral sucker. They use this to fasten on to other fish, and then use their rasp- like teeth to grind through their host's skin into the viscera. Jawless fish inhabit both fresh and salt wateWr environments. Some are anadromousT, moving between both fresh and salt water habitats. Extant jawless fish are either lamprey or hagfish. Juvenile lamprey feed by sucking up mud containing micro-organisms and organic debris. The lamprey has well developed eyes, while the hagfish has only primitive eyespots. The hagfish coats itself and carcasses it finds with noxious slime to deter predators, and periodically ties itself into a knot to scrape the slime off. It is the only invertebrate fish and the only animal which has a skull but no vertebral column. It has four hearts, two brains, and a paddle-like tail. ________________________WORLD TECHNOLOGIES________________________ WT Lampreys attached to a lake trout ________________________WORLD TECHNOLOGIES________________________ WT Mouth of a sea lamprey Pacific hagfish resting on bottom at 280 m ________________________WORLD TECHNOLOGIES________________________ WT Stir-fried hagfish, from Korean cuisine Cartilaginous fish Cartilaginous fish have a cartilaginous skeleton. However, their ancestors were bony animals, and were the first fish to develop paired fins. Cartilaginous fish don't have swim bladders. Their skin is covered in denticles, that are as rough as sandpaper. Because cartilaginous fish do not have bone marrow, the spleen and special tissue around the gonads produces red blood cells. Some cartilaginous fishes possess an organ called Leydig's Organ which also produces red blood cells. There are over 980 species of cartilaginous fish. They include sharks, rays and chimaera. Tiger shark ________________________WORLD TECHNOLOGIES________________________ WT Whale shark ________________________WORLD TECHNOLOGIES________________________ WT Stingray This elephant fish is a chimaera ________________________WORLD TECHNOLOGIES________________________
Description:The list of books you might like
