movement by dams, etc. Problems of relative growth and change in 



proportions. 

 Life Histories — many forms are still not completely studied. 

 Conservation — Fishways, their operation and limitations. Stream improve- 

 ment by construction of small dams and pools to promote aeration and 



refuges. 



Practical basis of legal restrictions— closed seasons, bag limits, si2;e limits, 



methods of fishing. 



Control of native and introduced forms. 



Pollution — maximum amount of organic pollution consistent with fish 



maintenance; industrial wastes. 



Hatchery problems — embryology; effect of varying conditions. 



Stocking streams — survival of eyed eggs, fingerlings, older fish. 



As stated before, classification is dependent upon a complete knowledge 

 of the anatomy, physiology and ecology of the organism. Obviously the be- 

 ginner must expect to devote much serious study to any group before he can 

 understand the reasons for the assignment of an animal to some special tax' 

 onomic postion. Even after an animal has been known and studied for years, 

 some new discovery may necessitate a change in its classification. When ex' 

 perts sometimes fail to agree, the beginner can hardly expect to escape making 

 some errors in the identification of animals. To aid him in the use of the 

 following key and in beginning a study of fish taxonomy the following descrip' 

 tions and suggestions are offered. 



Capturing Fish 



Small fishes may be taken with a dip-net, minnow trap or seine. Larger 

 ones may be taken in nets of various types as used by commercial fishermen 

 or, if time permits, by hook and line. The game laws should be checked care- 

 fully. Some states require one to take out a fishing license before he may 

 catch or have in his possession a native fish of any kind, even a minnow. Special 

 licenses are often required for the use of seines and other types of nets, and the 

 si2;es of mesh and net are limited. Since violators may be fined a certain amount 

 for each fish held illegally, a bucket of minnows might cost one a small fortune. 



Preserning Fish 



If possible, the live fish should be drowned in strong formalin, and then 

 promptly transferred to 5% formalin for storage. This procedure results in 

 the extension of fins, which is of much help to the student later, when fin-rays 

 may have to be counted and measured. If the fish is large, 10% formalin 

 may be injected, by means of syringe and hypodermic needle, into the body 

 cavity. A penciled or India ink label, giving full particulars of season and 

 place of capture, should always be packed with each group. If several groups 



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