EASTERN BROOK TROUT 



Salvelinus fontinalis (Mitchill) 



The brook trout was originally distributed throughout the Great Lakes 

 drainage, northward into Labrador and southward in the Appalachians into 

 Georgia. One of the most attractive of our native fish it has since been dis- 

 tributed all over the country wherever suitable habitats are thought to occur. 



The chief limiting factor in the distribution of the brook trout is water tem- 

 perature. They are the most critical of the trout in this factor. Although they 

 may exist in water temperatures much higher for short periods of time they nat- 

 urally are rarely found thriving in temperatures much above 65-70 degrees 

 Fahrenheit. 



Brook trout are fall spawners seeking out suitable areas in the headwaters 

 near the small, spring-fed tributaries. Here the eggs will be insured of clear, 

 cold well oxygenated water. They are the choosiest of the trout in picking their 

 spawning area. From late September to mid-December spawning brook trout 

 may be observed. Mature females average around 1500 eggs per fish. Brook 

 trout inhabiting lakes run up inflowing tributaries while the stream residents 

 migrate upstream to the spawning areas. Brook trout have been reported as 

 spawning successfully without access to streams in lakes or ponds having the 

 gravelly shores with a seepage of spring water. After the female selects the 

 nesting area she begins to dig the Q.gg pits using the caudal fin and the caudal 

 peduncle. Each Qgg pit when completed is from one to two feet in width and 

 6 or 7 inches deep. At the actual time of spawning the male swims along the side 

 of the female both vibrating from side to side. The eggs are extruded and ferti- 

 lized at this time. Eddy currents set up in the individual tgg pits circulate the 

 eggs insuring proper fertilization and preventing the eggs from washing down 

 stream. At this time the eggs are adhesive and as they touch the bottom gravel 

 they adhere to it. Digging activities of the female then cover the eggs with 

 several inches of gravel. The eggs hatch in from one to three months depend- 

 ing on the temperature of the water. When first hatched the prolarvae remain in 

 the gravel feeding on the yolk sac. As the yolk sac becomes absorbed they become 

 more active and begin to work their way out of the gravel nest. 



The young fry feed first on larvae and small aquatic insects. Brook trout 

 in Maine lakes feed on smelt, sticklebacks and minnows and to a large extent on 

 surface insects. By far the most important food in Maine lakes is the smelt. 



The following total lengths in inches are taken from the Maine Survey re- 

 ports of the Rangeley Lakes: 



Age II III IV V VI VII 



Total length in inches 8.2 9.6 12.2 15.3 17.9 19.5 



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