This section is from the book "Fish Hatching, And Fish Catching", by R. Barnwell Roosevelt, Seth Green. Also available from Amazon: Fish Hatching, And Fish Catching.
Before passing to the consideration of other kinds of fish, we desire to speak of species allied to the salmon and trout, although different in many of their habits.
Much excitement was created in the year 1873 among ichthyologists, by the discovery in some of the streams of the state of Michigan, of a variety of fish not previously supposed to exist in the United States, called the grayling. The grayling is a much esteemed European fish, common on the continent and in certain streams of England. It is a good sporting fish and excellent for the table, and as it spawns in a different season of the year from trout, it furnishes food and sport at a time when trout cannot be killed or eaten. The existence of such a variety might be of great benefit to the older states if its acclimation was possible and it should prove as well adapted to eastern waters as to those of the state of Michigan.
Mr. Seth Green proceeded to Michigan in the spring of 1874. So little was known of the habits of the fish that he arrived after the spawning season was nearly closed. On the 30th of April he reached the Au Sable river where they are supposed to be most abundant, although they are known to exist in all the streams of that region. The weather was still very cold and much difficulty was experienced in effecting the purpose of the expedition. The water of the river was found to be forty degrees Fahrenheit, but the air at that time ranged from sixteen to twenty degrees. Finding that the spawning season was over, Mr. Green dug up some impregnated eggs which had been deposited in the natural method, and capturing some living fish, left on his way back with eighty large grayling in eight twelve gallon milk cans, and one hundred and six eggs. He arrived at Caledonia on the 6th of May, with the loss of one dead fish and two fatally injured. From conversations had with trappers and hunters, it is supposed that grayling are found in the Au Sable, Manistee, Muskegon, Boardman, Au Gray, Rifle, Marquette and Cheboygan; in the latter in company with the brook trout. The latter fact would go to confirm the impression that grayling would live in our trout streams.
The adult grayling were placed at first in a pond with a small water supply. Here they did not seem to do very well and were soon transfered to another pond which had a strong current. In this they recovered, but preferred to lie at the head of the pond and in the quickest current. They soon became tame and mixed with the brook trout without being molested. They were fed the same food and treated in all respects as the brook trout.
The eggs, one hundred and six in number, were hatched out in the same way as the eggs of the brook trout; their incubation taking about the same time. The young fish looked at first like the whitefish ; but the young grayling is larger and has a larger sac than the white fish, though smaller than the brook trout. They took food very readily and though it was very neat work at first to feed them, after they had grown a little they gave no trouble. There is no doubt that they can be raised artifically, but the question remains whether that is worth while. They are more delicate to handle, require as much care and must have equally difficult conditions.
When first hatched they lie on the bottom like young trout, but commence to swim on the third or fourth day.
May 5 - Eggs arrived from Michigan.
" 8 - First egg hatched.
" 11 - All eggs hatched out; one lost.
" 12 - First fish began to rise and eat.
" 15 - All swimming. The eggs are nearly as large as trout eggs, but of less specific gravity. The fry resemble the young of the whitefish. They were about three inches long in December. Of the value of the discovery the future only can determine, but some excellent results may still flow from this undertaking. These are the first and only grayling ever hatched artifically. Up to the present time, however, March 1879, the grayling have exhibited no desire to spawn, and do not enter the raceway for that purpose. What they would do if turned out free in our eastern streams we cannot say, but when kept in confinement they will not spawn with us, and hence are useless to the fish eul-turist, whatever they may yet prove to be to the sportsman.
 
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