20 U. S. BUREAU OF FISHERIES. 



said that it comprised a fjently slopin«2: piece of fj;roimd about 6 acres 

 in extent, which was watered by three sprinj^s. collectively yieldinf^ 

 about 500 gallons of water per minute. The fish-cultural basins were 

 rectangular excavations about 120 feet long by 12 feet wide, with a 

 depth of 5 feet. These inclosures were cement lined, owing to the 

 gravelly character of the ground, in order to retain the water. 

 The various basins had the same general level and were separated by 

 sliding gates of wire gauze sufficiently fine to prevent the inter- 

 passage of the fry. For each of these inclosures 20,000 yearlings or 

 3,000 two-year-old fish were considered sufficient. If the propaga- 

 tion of crustaceans was ordinarily successful, the 20,000 yearlings 

 or 3,000 two-year-old trout would subsist royally for a month in a 

 tank of the size indicated. They would eat on an average 20 to 25 

 pounds per diem, or 600 to 800 pounds in the month. Mr. Mason 

 stated that each tank would produce 650 to 900 pounds of " Crevettes " 

 (amphipods) to say nothing of Daphnia, Cyclops, and other species, 

 simultaneously produced in the same inclosures. When at the end 

 of the month the food of one tank had been depleted, a gate was 

 opened and " the fish were driven like a flock of sheep to a new and 

 similar pasture." The first tank was then closed and left quiet, while 

 the process of self-replenishment of the stock immediately began. 

 Again at the end of two or three weeks the water was swarming 

 with the aforementioned organisms. 



At an establishment in Spain operated by F. Muntadas (1887) no 

 attempt was made to raise crustaceans as, it was said, a- plenteous 

 natural supply was always available. Muntadas wrote that ever since 

 his first season he had used nothing but small " shrimp " for feeding 

 his trout, which grew amazingly fast. However, in the large in- 

 closures, the fish found, besides the myriads of small shrimp, tad- 

 poles, gudgeons, and crawfish. The fish were stated to be very fond 

 of crawfish especially in the shedding period. Some of the fish in- 

 closures were referred to as stone basins, which produced on an 

 average of 1,200 trout every year, while certain "open-air basins" 

 contained young fish by the thousands. The young fish were said 

 to remain in one place from March until September and were fed 

 two or three times a day according to their needs. During the first 

 two months the food consisted of assorted small shrimp. The daily 

 quantity weighed 5 kg. (11 pounds). By carefully counting the 

 number of shrimp in 5 g. (about one-sixth ounce) he found the 

 number to be 672. The total number of shrimp fed to the fish in one 

 day was, then, not less than 672,000, or 4,704,000 per week. 



Keferring to the use of crustaceans as fish food in England, A. N. 

 Cheney (1892) quoted from a letter received by him from Thomas 

 Andrews, of Guilford, " whose reputation as a successful fish propa- 

 gator was broader than his native land." Mr. Andrews stated that 

 he had made a specialty of natural food for his trout, devoting sev- 

 eral boxes, 10 or 12 feet long, 6 feet wide, and 1 foot deep, besides 

 several small ponds and side streams, to the purpose of raising 

 Gammarus pulex mostly. He regarded young Gammarus as the 

 best of food for 7-week-old trout fry. He raised large trout in 

 ponds containing an extraordinary amount of natural food. 



Von Marenzeller (1882) described in some detail a fish-cultural 

 establishment in Germany owned by August Fruwirth. The young 



