Shrijnp flour and grist is also subjected to adulteration. At times carapace fragments 

 from table crabs are added. Many flours are contauninated by sea stars and fishes. Other 

 flours are much too salty. I liave often investigated cases where severe intestinal 

 inflsinmation had occurred from salty shrimps. It is advisable therefore to purchase dried 

 shrimps in natural form, to always taste it, and to personally run it through the chopper 

 with the main food. Many growers scald the shrimps in advance with hot water. Additions 

 of dry shrimps should not be too generous on account of high prices. Shrimps, for a long 

 time, have been too expensive a component of food mixtures. On the other hand, I con- 

 sider it v/rong to regard shrimps as "crude fiber" and to compare its food value only to 

 the action of sawdust. 



Wollhand Crab Groats has been placed on the market, since the abundant occurrence of 

 the Wollhand crab in the lower Elbe P.iver, by a firm 'jnder the names "Egeo-Oroats" (100 

 pounds about $3.03) and "Egeo-Flour" (100 po-onds about $3.23). The following analysis is 

 given ! 



Protein (including chitin, therefore only 22.2it digestible ... 38.22^ 



Fat 9.9^ 



Calcium phosphate ^ . 24 



calcium carbonate 27 .72 



Silicic acid (Silica) 0.58 



Sodium chloride (salt) 0.95 



An experiment which I made with slaughterhouse scraps (pork scraps) plus 18 percent 

 of VTollhand crab groats on rainbow trout fingerlings with one feeding per day gave a food 

 quotient of 5.25, whereas the parallel experiment with slaughterhouse scraps only, gave 

 a quotient of 5.7. A second experiment with an addition of 20 percent Wollhand crab 

 groats led to a food quotient of 5.2 and a piece loss of 7 percent. The comparison 

 experiment with pork scrap gave this time an even more favorable food quotient of only 

 ii.5, the piece loss percent. It was apparent that the food with Wollhand crab groats 

 was more poorly digested than the food without addition. Possibly the pix)duct available 

 up to now is capable of improvement. Quite good results are said to have been gotten 

 here and there by feeding fresh Wollhand crabs. 



Mussels and Snails . As a mass food material for trout growing, sea mussels which 

 can be obtained in the live state by the grower, should be mentioned above all. They ar*> 

 a hif^hly valuable food material which should be reserved primarily for spawning trout, 

 inasmuch as it causes a fine color in the eggs. The shells gape after a brief dip in 

 boiling water and the animal can be removed. The yield of flesh is not very large so 

 that even this food is not cheap. If the mussels are to he used only as addition food, 

 they may simply be put through the chopper and fed, in the same way as edible snails 

 and other land mollusks. The shell fra,Tiients act only advantageously in the total 

 food. Trout under natural living conditions also eat larger amounts of snail shells. 



Frogs may be fed to trout or after suitable preparation also to carps. Spawn ripe 

 female frogs should first have the ovaries removed. As to tadpoles, see Chapter XIV. 

 Living tadpoles are very seldom eaten. 



Leafchafers (Melolontha vulgaris). June bugs . Their use for feeding pays only in 

 swarming years, and for small pond management. This feeding was first recommended by 

 Eckstein. The beetles are killed by scalding, put through the chopper and mixed with 

 meat flour, until a mass like mashed potatoes is obtained, and then fed to the trout. 

 For carps a mixture is recommended of 50 percent leafchafers and 50 percent lupine 

 groats, v^iich later may also be replaced by barley, potatoes with 2 to ^ percent of 

 feed lime, etc. If Isirger amounts of leafchafers are available, they can after scald- 

 ing with hot water be placed in sacks cind dried on a baking oven (for the small fishery). 

 In this connection, I shall mention also that chopped earthworms are a good food for the 

 smallest broodlings. 



Natural Small-Animal Nutrition , The feeding of natural small -animal nutrition only 

 comes into consideration in the growing of trout brood and of course in fattening. 

 Although we could hardly succeed in giving all food in the form of natural food, yet a 

 portion of natural food can greatly iiH)rove the total food. Experiments in the fish 



