- From the Pennsylvania TIC program
- As a class, discuss the survival percentages of brook trout that survive to spawning age (2-3 years old) in Pennsylvania’s healthy headwater streams. (Only 1-2% of eggs laid survive to spawning age of 2 or 3 years.) Refer to the Life Cycle Background pages in the PA TIC Aquarium Resource Guide to lead the discussion.
- Discuss the expected survival of their TIC brook trout. Be sure to cover the time period in which they will experience trout loss throughout the TIC school year. Use the Trout Care pages in the PA TIC Aquarium Resource Guide to lead this discussion.
- Explain to students what a survival pyramid is. Using the percent of survival for each level of the “survival pyramid” or life stage provided below, have the students create survival pyramids for both a wild female Brook Trout and a hatchery raised brook trout.
- Have students determine how many trout survive in each stage, beginning with the number of eggs. Before beginning, have students draw two pyramids and label one “wild brook trout” and the other “hatchery-raised brook trout.” Have them label each level of the pyramids with the appropriate life stage from bottom to top – egg, alevin/sacfry, fry, adult. Provide the information below to students for each pyramid.