LAKE TROUT BREEDING HABITS 



65 



z 

 < 

 in 5|— 



100 20D 300 40^ 



MAXIMUM DEPTH IN FEET 



Fir.iRE 2. — Relation of average date of peak of lake-trout 

 spawning activity and maximum depth of some New- 

 York lakes. 



deep at a time well in advance of the turn-over 

 period of the lake. Data taken from September 

 29 to October 17, 1941, showed that the surface 

 temperature ranged from 57° to 62° F. 



This large deviation in the time of spawning 

 may be attributed to racial differences in the lake 

 trout. Milner (1874) gives the spawning time of 

 the siscowet (Cristmimer namaycush siscowet) as 

 late August and early September in the deep 

 waters of Lake Superior. In the same lake the 

 common lake trout {Salreliniis [ = ('ristimmer] 

 namaycush) spawns in from 7 feet to 15 fathoms 

 of water during the month of October and in early 

 November (Milner 1874, Van Oosten 19:55). 

 Hubbs (1930) has described the Rush Lake trout 

 {Cristivomer namaycush huronicus) and states 

 that it spawns in deep water in late summer rather 

 than in fall, as does the common lake trout in the 

 same lake. Dymond (1926) gives the time of 

 spawning of the common lake trout as the month 

 of October in Lake Nipigon, Ontario. But he 



points out that tliere is a race of black trout in 

 the same lake which ascends some of the tributary 

 streams and starts spawning about September 20, 

 and a third race which is said to spawn in deep 

 water from October 20 to November 10. 



In New York State the spawning data indicate 

 that two races' of lake trout e.xist: One, the 

 Seneca Lake trout, spawns early in deep water, 

 and the other, widespread in the Finger and 

 Adirondack Lakes, spawns in shallow water at 

 about the time of the turn-over of the lake. 



With these differences in reactions and spawning 

 habits, it would be desirable to determine if the 

 Seneca Lake trout can adapt themselves to the 

 conditions existing in Adirondack Lakes and vice 

 versa before extensive stocking is attempted. 

 Lntil such knowledge can be secured it would be 

 wise to stock lake trout in lakes similar to those 

 from which the eggs were obtained. 



DURATION OF THE SPAWNING PERIOD 



Data on the receipt of lake-trout eggs at some 

 of the New York State hatcheries are summarized 

 in table 5. The date of receipt of eggs corresponds 

 closely to the date of take, except for the first 

 one or two days of the spawning season. Ordi- 

 narily, only a few ripe fish are found at first, 

 and if only a few thousand eggs were obtained, 

 they often were held for a day or two until more 

 eggs were available to make the trip to the hatchery 

 worth while. The date the first eggs were taken 

 probably averages about 1 day earlier than the 

 date of their receipt at the hatchery. At the 

 peak of the spawning season the eggs were usually 

 rushed to the hatchery immediately, so the date 

 of the peak receipt of eggs corresponds to the date 

 of the peak egg take. 



The tlata in table 5 do not indicate the com- 

 plete spawning season but rather the season dur- 

 ing which it was feasible to catch and strip the 

 trout. High water sometimes so affected the 

 fishing of the nets that it was not practical to 

 continue fishing, and bad weather sometimes cut 

 short the stripping operations. Hence, a short 

 period of egg take is not necessarily indicative of a 



1 other evidence of racial dilTerence is available. New York State fi.sll 

 hatchery foremen agreed that ckks from Seneca Lake trout averaped ahout 

 240 an ounce, while egps of lake trout of comparable size from Adirondack 

 lakes averaeed about 200 to 210 an ounce. No measurements of the actual 

 diameters of the ecRs were available, but the counts of the hatchery foremen 

 appeared to be fairly consistent. I). C. llaski'll (unpublished material 

 gathered in 1941) also reports that th<' Seneca Lake trout grow signifiointly 

 raster under hatchery conditions than the young laki- trout from Ranuelte 

 atHi t'pper Saranac Lakes. 



