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Brook Trout

Brook Trout, illustration by Maynard Reece, from Iowa Fish and Fishing.

Characteristics

Brook Trout are easily recognized and distinguished from other trout by vivid white lines on the front or leading edge of the lower fins, and the top portion or back is covered with light wormy streaks or mottlings on a darker background called vermiculations. The dorsal fin has ten rays and is also strongly mottled. The vomer is trough-shaped, with the teeth restricted to the front portion. Brook trout feel soft to the touch because of the very small scales that cover the whole body. About 230 scales are along the lateral line, and they are more deeply embedded than other trout in the genus Salmo.

Distribution

Brook Trout Distribution

Native to Iowa; originally abundant in most spring-fed streams of northeastern Iowa, although some fishery investigators believe they were restricted to the Upper Iowa River drainage. Confirmation of the original distribution is difficult because early explorers referred only to the fish as "mountain" or "stream" trout, without looking for identifying characteristics. Natural reproduction of Brook Trout is presently limited to only a few streams.

Foods

Fish, small crayfish, or even snails, but insects, both terrestrial and aquatic, generally make up the bulk of their diet. In streams with watercress, brookies feed heavily on scuds, which are small amphipods often found in abundance near springs.

State Record

7 pounds, 19.75 inches long- 1996 - Doug Kovarik, Marion, Iowa

Expert Tip

Use fine line and approach pools quietly to improve your fishing.

Details

Brook Trout live in cool, clear headwater spring ponds, springs, and spring-fed streams with shallow riffles over gravel and rubble bottoms. Synonymous with the cold waters, Brook Trout are seldom found in water with temperatures higher than 50-60 degrees. Needing the coldest and cleanest of stream conditions, Brook Trout are highly sensitive to pollution, siltation and poor water quality.

Wild Brook Trout are among the most beautiful of all fish at spawning time. Male trout, during this late fall period, develop a deep red-yellow-crimson coloration along the belly. The sides of the fish often have many red and pale yellow spots, with each spot sometimes surrounded by a blue-colored circle.

Brook Trout spawn from late October to November. Females build redds or nests in clean gravel areas, often near the headwaters of spring-fed streams. Females can sense upwelling springs or other gravel areas with groundwater flow and often deposit their eggs in these habitats. At a constant water temperature of 50 degrees, the eggs will hatch in about 45 days. In colder water, the eggs might not hatch until January or February. The tiny fry stay buried in the stream gravel and survive on natural nutrients stored in the yolk sac until the water temperature starts to rise in early spring. At this time, the fry swim up through the open crevices of the gravel bottom and start looking for tiny insect life to eat.

Females mature at about two years of age, with most males becoming mature during the first year of life. Young females spawn between 200 to 500 eggs, but a larger fish may produce 2,500 or more. Brook Trout reach 3- to 6-inches long the first year, 7- to 9-inches the second, and 10- to 13-inches in the third year of life. Brook Trout weighing over one pound are considered a trophy, since life expectancy is seldom more than three years.

Brook Trout live in the confined areas of our small streams, often spending most of its life in a single pool-riffle. Three habitat components are needed for Brook Trout to survive: resting areas in pools, feeding sites near riffles or swiftly flowing water, and escape cover which is normally found along undercut banks, beneath tree limbs or under large rock ledges.

Recent stream sampling information is available from Iowa DNR's biological monitoring and assessment program.

Sources:

Harlan, J.R., E.B. Speaker, and J. Mayhew. 1987. Iowa fish and fishing. Iowa Conservation Commission, Des Moines, Iowa. 323pp.

Loan-Wilsey, A. K., C. L. Pierce, K. L. Kane, P. D. Brown and R. L. McNeely. 2005. The Iowa Aquatic Gap Analysis Project Final Report. Iowa Cooperative Fish and Wildlife Research Unit, Iowa State University, Ames.

Illustration by Maynard Reece, from Iowa Fish and Fishing.


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Present in these Iowa water bodies:
Lake/Stream County Location Acres/Length
French Creek Allamakee Located on French Creek Wildlife Management Area and private land 6 miles northeast of Waukon. 5.60
Clear Creek - New Albin Allamakee Located on Clear Creek Wildlife Management Area, 4 miles east of Dorchester along Sleepy Hollow Drive. 3.40
Little Paint Allamakee Located in Yellow River State Forest, 3 miles west of Harpers Ferry just off of State Forest Road or CR B25. 3.00
Pine Creek Allamakee Located on Pine Creek Wildlife Management Area, 2 miles northeast of Sattre on Balsam Road or CR W60. 2.50
McLoud Run Linn Along the east side of I-380 in central Cedar Rapids 2.50
Spring Branch Delaware 3 miles east-southeast of Manchester off 205th Avenue. Parking available near highway 20 overpass and Manchester Fish Hatchery 2.20
North Cedar Creek Clayton Located 3 miles west of McGregor off of CR B60 or Ivory Road. 2.00
South Pine Creek Winneshiek Located 1.5 miles southeast of Sattre. 2.00
Pine Spring Creek Winneshiek 6.5 miles north of Decorah. Take Hwy 52 north and then North Winn Road (W34) north to Seed Savers' Exchange. 2.00
Lansing Wildlife Area Creek Allamakee Stream is located in the Lansing Wildlife Management Area. T99N, R3-4W, S11, 12, 13, 14, 18 1.68
Middle Bear Creek Winneshiek Stream located 7 miles northeast of Highlandville. T100N, R7W, S14, 15, 16 1.30
Baileys Ford Delaware 3 miles southeast of Manchester - follow signage from Jefferson Road. 0.60
Casey Springs Winneshiek Take Pole Line Road 2.2 miles west from Hwy 52. Turn north on Bluffton Road for 2.3 miles to Sindelar Wildlife Access 0.50
West Branch French Creek Allamakee Located on French Creek Wildlife Management Area 6 miles northeast of Waukon. 0.40
Trib to French Creek- French Creek Road Allamakee Located about 9 miles northeast of Waukon, just off French Creek Road. Tributary to French Creek. 0.40
Dutton Springs Creek Fayette Located 3 miles northeast of West Union in Dutton's Cave Park. 0.27
Falcon Spring Winneshiek Take Pole Line Road about 6 miles west from Decorah to the Falcon Spring Wildlife Management Area. Visitors must hike approximately 1.25 miles to reach the spring run. 0.20