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Date added: 5.3.2015
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This easy-to-read Kindle edition, equivalent in length to a physical book of approximately 24 pages, consists of articles especially written for the esteemed multi-volume reference work “World Book: Organized Knowledge in Story and Picture” (1919 edition). Learn how fish live, reproduce, find food, defend themselves, and more. Also learn about twenty specific kinds of fish, including the halibut, herring, mackerel, salmon, shark, trout, and tuna.Sample passage:Many fish are absolutely without anxiety concerning their eggs or young. The eggs are deposited in chosen localities, on rocks, weeds or at the bottom of streams and there left to hatch or be destroyed, as chance may determine. The loss of eggs and young is very great, for almost every species is the prey of larger fish- so in order to preserve the existence of species a vast number of eggs is deposited. A cod produces about 10,000,000 eggs annually, but beyond depositing them, does nothing to ensure their preservation. Other fish, however, are examples of parental care and forethought. The humble stickleback builds a nest of sticks carefully plastered together with gummy excretion, and when the eggs have been deposited stands guard until the young are hatched. Bass and sunfish also guard their eggs. The salmon and the shad ascend rivers to deposit their eggs- the eel reverses this process by returning to the sea to spawn. The eggs of sea fish are hatched more quickly than those of fresh water species. In the sea the loss among the young is greater than in rivers and bodies of fresh water, as there are more species to prey on each other. Some sea fish hatch from the eggs forty-eight hours after deposit- the eggs of the brook trout require three months for hatching.About the author:George Wagner (1873-1954) was Professor of Zoology at the University of Wisconsin. He introduced courses in ornithology, bionomics, and ecology, and guided early cooperative investigations with the State Conservation Department on wildlife management. Denizens of the Deep: A Brief Guide to Fish by George Wagner
