XXYIII REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



Observations as to the effect of low temperature on trout eggs con 

 firmed the experience of the previous season. Eggs eyed and hatched 

 entirely in the spring water (ranging from 45° to 50°) yielded a larger 

 percentage and better fish than those taken under the same conditions 

 and at the same time which were hatclied in water varying from 32° to 

 50° in temi)erature. The comparisons were made with eggs collected 

 at Caspian Lake. It was also observed that eggs eyed in spring water 

 before being subjected to colder water yielded a larger percentage than 

 green eggs laid down in cold water. The investigations were carried 

 still further by trying different temperatures during the period of incu- 

 bation on various lots of eyed eggs, but these were not fully comi)leted 

 owing to an accident to the water supply during the critical period. 



It was intended to carry all of the eggs after they were eyed in a 

 mixture of the spring and river water, the spring-water supply being 

 insufiicient, but on the dth of March, and periodically from tliat time 

 to April 15, it became necessary to shut off the spring water entirely. 

 The eggs were thus subjected to the reduced water temperature from 

 12 honrs to 16 days at a time, the temperature during these periods 

 ranging from 32.4° to 35°. After reaching 32J° the develo])ment of the 

 eggs waa apparently sus})ended for several days, which accounts for 

 the length of time between the commencement and the end of the 

 hatching periods with the various lots. One lot of 35,000 was placed 

 in water registering 32i° as soon as eyed and kept there until they 

 hatched, for the purpose of comparing the results with those obtained in 

 hatching in spring and river water mixed. They commenced hatching 

 March 15 and finished April 24, the total loss to May 30 amounting to 

 520 eggs and 1,435 fry. An equal number of the same lot of eggs 

 placed in mixed water, but subjected to changes caused by shutting off 

 the spring water periodically, began hatching February 26 and finished 

 April 15, Avith a loss of 1,223 fry and 487 eggs to May 30. Better 

 results would undoubtedly have been secured had it not been necessary 

 to shut off the spring water. 



In addition to the collections made in the vicinity of the station 

 300,000 quinnat-salmou eggs were received in December from Battle 

 Creek, 5,000 landlocked-salmon eggs from Green Lake in February, and 

 100,000 steelhead-trout eggs from Fort Gaston in April. The qumnat- 

 salmon eggs arrived in excellent condition and commenced hatching 

 on April 3 in water of an average temperature of 34°, but during the 

 hatching period it went down to 32^° on several occasions. The fry 

 resulting from them numbered 200,000 at the time of their distribution. 

 They were deposited in tributaries of the Connecticut and Merrimack 

 rivers during the month of July. During incubation white spots appeared 

 on some of the embryos, causing the loss of many. Those on which 

 the spots were most noticeafble were separated from the others and in 

 a large number of instances they hatched, the spots disappearing with 

 the absorption of the sac. The steelhead-trout eggs arrived during a 

 l^eriod of unusually warm weather and were in very bad condition, 



