Kendall. — Rainbow and Steelhead Trout 197 



Dr. Kendall: No, I do not know that they have been mixed 

 except in cases of which I have read. 



Mr. Titcomb: I have mixed them a number of times; in fact, I 

 have entertained the idea, from what I have read, that the steelhead and 

 the rainbow were merely variations of the same fish. 



Dr. Kendall: That has been a common impression right along. 



Mr. Titcomb : Something like 30 years ago I was .talking with 

 United States Commissioner McDonald, and I asked him what results 

 he had obtained with rainbow trout in the east. I remember he stated 

 that they had sent great numbers of them into the waters of New York 

 state, and that they had all disappeared. I have not had much exper- 

 ience personally with New York waters, but it is particularly interesting 

 to me to study the results of planting rainbow or steelhead trout. We 

 do not know absolutely what waters are suitable for rainbow trout. It 

 is a curious thing, but we have streams in New York and a few in 

 Vermont where the planting of rainbow trout has been followed with 

 very good results, and where they have reproduced and maintained 

 themselves afterwards. But in the majority of these streams in New 

 York state where the rainbows have been planted, the fish have abso- 

 lutely disappeared ; and yet there are streams which we annually plant 

 with fish and which afford good fishing for the rainbow trout so-called. 

 It is corroborated by anglers that these are good rainbow trout streams. 

 Now we choose for the rainbow, as we do for the brown trout, the 

 lower waters of the streams where the tendency is for the water to 

 become considerably warmer and is not congenial for the native brook 

 trout. We do not consider the rainbow so destructive to the brook trout 

 as the brown trout. The rainbow trout, if planted in the headwaters, 

 naturally works down into the larger, deeper pools of the lower part of 

 the stream, where the temperature is higher. They are certainly a fine 

 fish to catch on the fly, too. 



Mr. W. H. Rowe, West Buxton, Me.: I have fish at my place that 

 I have raised that came from the Wytheville, Va., hatchery. They are 

 called rainbows and they spawn in November or December. I have fish 

 that came from the Pacific coast, called rainbows or steelheads, that spawn 

 in April. Can you explain why this should be? 



Dr. Kendall: The spawning of Salmonidae, as well as of other 

 migratory fishes — and most of them them are more or less migratory — 

 is in conformity with a certain temperature range. They must have a 

 certain temperature in which to spawn, and that spawning period is 

 determined by the temperature prevailing in the rivers at a partic- 

 ular time. For instance, the migratory fish start from the sea; they 

 ascend the rivers and reach the spawning waters at a certain time, but 

 if the temperature is not right they wait for it to get right before they 

 spawn. So we have temperature and other river conditions to which 



