FEEDING AND REARING FISHES. 
309 
REPORT BY M. CHABOT'KARLEN ON THE FISH-CULTURAL OPERATIONS OP M. DURAND, 
AT THE SCHOOL OF AGRICULTURE AT BEAUNE.* 
The author states that tish-cultaral operations were commenced at tlie School of Agriculture 
and Viticulture of Beaune in 1886-87, near tlie Bouzaize, one of the aitluents of the Sadue; that there 
were at the time no trout in the vicinity or in the iioighboriug rivers, and that it was necessary to 
buy eggs. The first year 12,000 fry wei’e obtained, which were divided into three lots. Two lots of 
3,000 each were planted in the Onche and Mnzin: the rest were liberated in the Bonzaize or held in 
confinement near the shore and fed on Cyclops and afterwards on GammarHS. The second year 17,000 
fry were obtained; the two rivers above named received 6,000, the Vouge but 1,000; 500 were planted 
in the Love, and the rest pnt into the Bonzaize, a part at liberty and a part m confinement. At the 
present time 18,000 fry are ready to be distributed. In three seasons 47,000 fry have been turned out. 
In the Onche, in which the trout were previously unknown, it is now possible to take them 
weighing 400 grams (about 14 ounces), those that were put in first being 23 mouths old. M. Brossard, 
director of bridges and roads at Bliguy-snr-Ouche, says that numbers of them of this weight can lie 
seen in the upper parts of the stream. As to those 1 year old, they have attained a weight of 100 grams 
(about 31 ounces). Moreover, natural reproduction will commence next season, and the conditions in 
this river are so favorable that its stocking by this method is assured, as the fish will bo in condition 
to spawn in December, 1880. In the Mnzin the same results would have been obtained had it not been 
for poaching. Nevertheless, in spite of this and of the devices of every kind that were einjiloyed by 
the mills along the stream, the trout reappeared in the Mnzin, 
More or less similar results were obtained in the Bonzaize. Reared in captivity in receptacles 
abundantly provided with aquatic plants, Potamogeion and cress, and fed with Cyclops and a<inatic 
larvas of every kind at first, and then with Gammarus, the trout gained in a year an average of 60^ 
grams (about 2 ounces). At this age they were not able to cope with the large pike that infested 
the mill course at the head of the river; this was emptied and the larger ones taken out, only those 
of the size of the young trout being permitted to remain. Now, at the age of 23 mouths, a great 
number of the trout weigli more than 300 grams (about 101 ounces). The following are the weights 
of some taken in the river: First, 365 grams; second, 360 grams; third, 280 grams; average weight, 
335 grams (about 111 ounces). So that in a year their weight increased from 601 to 335 grams, a gain 
of 2741 grams in twelve months. Natural reproduction may be expected to commence in this river 
from December, 1889. 
The report also contains observations on the Cyclops (which are presented with a view to furnish- 
ing the basis of a method for the rearing of these), the Daphnia, and the Cypris, with some remarks 
on the monstrosities found with the eggs of the trout and a statement of prices obtained for trout. 
The Cyclops possesses an extraordinary fecundity, and reproduces at a temperature of from 8^ to 
10° C. (46° to 50-^ F. about). In winter they seek the bottom and hibernate in some sort, but on 
capturing them and placing them in a high 3r temperature their generative organs will be seen to 
revive. Thirty-five degrees C. (95° F. ), however, according to our experience, is the highest they 
can resist. The best for hatching is between 20° and 25° C. (68° and 77° F. ). At this temperature there 
forms on each female every two days two egg-bearing sacs, or external uteri, wherein the eggs are 
hatched. At the end of two days these organs become detached and fall to the bottom. The number 
of eggs contained in each may be from 16 to 32, but generally the number of young obtained is some- 
what less. However, the eggs hatch immediately, and the young Cyclops which issue forth are almost 
globular, having but four feet and no tail. At the end of fifteen days they undergo a molting, the 
tail appears and other feet form, and fifteen days after — that is, a mouth in all, the Cyclops are mature 
and ready to reproduce. 
With such fecundity, it can be readily understood how numerous they become. Carbonate of 
lime is necessary in the formation of their shell. From the fact that they are found in abundance in 
water infused with vegetable matter in decomposition, the water, nevertheless, not contracting the 
least odor, it is supposed that thej^ live on infusoria, and that, therefore, the means by which the fish- 
cultnrist may have them at his disiiosal is to multiply in his rearing ponds aquatic iilauts. {Potamo- 
* The report was published by the National Society of Agriculture of France, June 19, 1889. The 
papers in this Appendix were translated by Mr. F. P. Fennell, of the U. S. Fish Commission ; none of 
them have been translated in full, only such portions being presented as apply to the feeding and 
rate of growth of the fishes. 
