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Illinois Perches - Early Childhood Edition

The Basics
Classification:
Perches are fishes. There are 28 kinds of perches in Illinois. All but four of them are darters.
 
Appearance:
Because there are so many types of perches, it is hard to describe what the appearance is like for the whole group. Here are some general traits.
 
 
NOTE: You may want to visit the “Vocabulary and Anatomy” section of the Web page at https://www.dnr.illinois.gov/education/Pages/WildAboutFishes.aspx to help you understand some of the information in the text.
 
Some types of fishes have one dorsal fin while others have two dorsal fins. Perches have two dorsal fins.
Perches have thoracic pelvic fins with one spine and five rays. Thoracic pelvic fins are fins on the fish’s belly that are located in the throat area. Some fishes have pelvic fins that are placed much farther back on the body. The number of spines (sharp supporting structures) and rays (flexible supporting structures) in the fins can help to identify a fish.
 
Perches have ctenoid scales. Ctenoid scales are scales that have small projections from the rear edge. A different type of scale has a rounded edge with no projections. There are other types of fish scales as well.
 
The body of most perches is suited for living on or near the bottom of a body of water and in water that is moving, often swiftly. They are compact animals with a long body that often is fairly flat on the lower side.
 
Male darters are often very colorful in the breeding season.
 
Size: 
The smallest darter in Illinois is about one inch long as an adult. The largest darter in Illinois is about six inches long as an adult. Most adult darters in Illinois fall in the range of two to three inches in length.
 
Saugers and walleyes range from about 12 to 30 inches.
 
Yellow perch can be six to 16 inches long.
 
The ruffe is about 10 inches long as an adult.
 
Location:
Perches can be found throughout Illinois, but many of them are restricted to specific areas and habitats.
 
Food:
Aquatic insects (immature and adults), small crustaceans and other small aquatic invertebrates make up most of the diet of darters.
 
Saugers, walleyes and yellow perch eat fishes and aquatic insects.
 
The ruffe eats aquatic insects.
 
Reproduction:
The spawning period is either in spring or summer.
 
Fertilization is external, with the male and female releasing the sperm and eggs at the same time.
 
Eggs are often placed in aquatic vegetation, algae, under rocks or in gravel.
 
No parental care is given to the young, although in some species the male stays with the eggs until they hatch.
 
Some species do have courtship behaviors.
 
Male darters are often very colorful in the breeding season.

 Educator Suggestions

​1. Watch the Illinois Perches video podcast with the students. Discuss with them the information shown above and in the video.
 
2. Have the students look at the photos of the perches accessible at https://www.dnr.illinois.gov/education/Pages/WAFPerch.aspx. Can they tell the males from the females? What colors do they find on these fishes?
 
3. Use the information presented above and the following suggestions to help you meet some of the Benchmarks of the Illinois Early Learning and Development Standards. Please do not be limited by these suggestions or by these Standards. The information can be used in several subject areas.
 
Goal 11, Learning Standard 11.A: Develop beginning skills in the use of science and engineering practices, such as observing, asking questions, solving problems and drawing conclusions.
 
Have the students develop questions about perches that were not answered in the text or video. Let them build models to represent their ideas. If applicable, let them test the ideas and collect data. Involve math and computations skills. Describe the results and provide explanations.
 
Example
 
Students want to know what animals might eat a darter.
 
Have them postulate what types of animals might eat a fish that lives on the bottom of a body of flowing water. What kind of adaptations would it need to catch and eat a small fish? Ask them to draw or describe these features. Make a list. Now provide them with field guides, the Illinois’ Natural Resources Trading Cards and/or other resources to look for animals that might possess these features. When they find one, discuss whether it is reasonable or not that the species might feed on darters.
 
Goal 12, Learning Standard 12.A: Understand that living things grow and change.

Have the students compare the approximate size of a darter egg with the size of an adult darter. Uncooked quinoa is about the right size for the darter eggs. The smallest adult darter in Illinois is about one inch long. The longest darter is about six inches long. Most darters are two to three inches long. Use some standard length shapes to represent these sized of darters and have the students sort them by size. Discuss how something that started so small could become so much larger. Note: Make sure that they understand that the quinoa is not what the fish develop from.
 
Goal 12, Learning Standard 12.B: Understand that living things rely on the environment and/or others to live and grow.

Discuss with the students what these fishes need to survive (food, water, oxygen, space, shelter, certain temperatures, etc.).
 
How are these needs provided to the fishes by the environment that they live in? What would happen if they could not obtain one of the needs from the environment?
 
Goal 13, Learning Standard 13.A: Understand rules to follow when investigating and exploring.

Depending on what questions the students develop and test, they may need to be reminded of safety rules..
 
Goal 13, Learning Standard 13.B: Use tools and technology to assist with science and engineering investigations.

Depending on what questions the students develop and test, they may need to use scientific and technological tools to help them discover the answers.