74 Thiriij-d.rih Annual Meeting 



the inipivssion lliiU I'niiihow trout ivijuircd a lower iciniicraliirc^ 

 than the speckled tioiit. Wlieii it is necessary to aerate the water 

 he pumps air of a high temperature into the cold water. I mere- 

 ly raised the question about aeration because it occurred to mo 

 ■that possibly some of the trouble from aerated water occurred 

 from pumping hot air into cold water. 



After visiting the Aquarium [ bired an automobih' with tlie 

 intention of visiting a commercial trout hatchery, said to be tlie 

 only one in France, situated near Cernay la Yille. The owner 

 of this hatchery is H. Callier. The automobile broke, down how- 

 ever, and wore on my nerves and I returned to Paris without 

 seeing the hatchery. I talked with the owner, however, who gave 

 me the following information. Besides selling more or less fry 

 and fingerlings, he produced for market 100,000 trout per year 

 on a water supply of 100 liters (26 gallons) per second. These 

 trout when sold weighed from one-fourth to one-third lb. His 

 pond system covered a M'ater area of 15,000 square meters (near 

 4 acres), divided into 54 ponds. The fish were fed on an in- 

 ferior species of sea fish and horse meat, and at the time of my 

 contemplated visit he was feeding about 180 kilos (400 lbs.) 

 per day of tliis kind of food in equal proportions. The food cost: 

 him about l"^ francs per 100 kilos (about 1 cent per lb.). Th(^ 

 highest water temperature during the summer for one month 

 ranges at about 22 dgr. centigrade (711/2 F.). He sorts his fish 

 and cleans his pond three times a year. The young fish he feeds 

 with liver once or twice a day. He claims he starts with 300,900 

 eggs in order to make 100,000 marketable fish. In other words 

 he raises to marketable size from eggs 33 1-3 percent. The head 

 reservoir which is the source of water supply for all of the ponds 

 contains 830,000 square meters (200 acres) of water. Most all 

 of these ponds are long and narrow, the longest one being 55 

 meters (180 feet). When transporting live fish, he places two 

 kilos (41/^ ll)s.) of fish in GO kilos (132 lbs.) of water in the 

 summer lime, and in cold wealher for ordinary distances, 4 kilos 

 (!) lbs.) of \\A\ to (iO kilos (132 lbs.) of water. The market 

 ])rice of ti'out Ibus raised averages about the same as it does in 

 this country, namely, 50 c. per pound, which in comparison with 

 the low rail's of food stuffs in France really is much higher than 

 the market price here. He confines his work entirely to the pro- 



