A-MEKICAX FISHERIES SOCIETY. 



THE GAMMARUS OR FRESH WATER SHRIMP AS 



TROUT FOOD. 



BY FRED MATHER. 



When I be^an broedinfi' ti'out, soniethinp,' over thirty years 

 ago. the gamnianis was thoiigiit to be an all-sufficient food for 

 trout of all sizes, and a beginner was advised to stock his 

 streams with them and then watch his trout grow. This idea 

 still prevails to a great extent, and because I do not value the 

 gammarus as highly as formerly, this paper is written. 



Trout from two to six montlis old live largely on the larvjp 

 of the many species of water breeding insects, together with 

 small crustaceans, such as gammarus. asellus. cyclops, etc., as 

 well as mature insects. Such small food is quite ''filling" for a 

 troutlpt. but a yearling is not entirely satisfied with such small 

 morsels, and adds snails and small fish to its menu. When our 

 trout is two years it looks for larger things, although a few 

 flies, by way of dessert, are still alluring, while very large trout 

 seldom rise for flies. 



Last winter I wrote a book which is now being printed by 

 Forest and Strann, entitled "Modern Fish Culture in Fresh and 

 ^'alt Water, with chaijters on the culture of Whitefish. by Hon. 

 Herschel ^Vhitakel•, and on the Wall-Eyed Pike, by James 

 Nevin." IVrhaps a (] notation from the chapter on natural 

 foods for trout will cover my views on this subject. I have 

 said: 



''If the fish are to forage for the whole or part of their food, 

 the pond should be stocked with such water plants as grow in 

 spring water, and then the crustaceans, gammarus and asellus 

 should be introduced. But beware of the burrowing crawfish, 

 for it not only enters into competition with the trout for its 

 crustaceans and insect larvte, but makes holes in dams. Be- 

 sides this, it cannot be eaten by small trout when it is in the 

 adult state, and when soft it hides. The gammarus is usually 

 called 'fresh-water shrimp,' while the asellus, or 'water asel,' 

 looks somewhat like the 'sow-bug' found in decayed wood. In 

 some waters these crustaceans grow to the length of three- 



