Crayfish Bring Science Lessons to Life for Third-Graders

Equipped with magnifying glasses and their knowledge about living organisms, third-grade students recently took on the roles of scientists to closely examine the structures of crayfish. As part of the Structures of Life unit in Karen Green’s and Stephanie Kennedy’s science classes, the students made observations, took notes and drew conclusions about how the crayfish, which has the ability to regenerate its appendages, has evolved over time in order to survive.

“The crayfish are an exciting addition to the classroom, as this is not an animal many students have been exposed to, and they provide a new and up-close and personal learning experience,” Kennedy said. “Students have been made aware that these organisms have been removed from their natural habitat in order for them to study them. We consider this a privilege, and, as a result, work hard to try to mimic their natural habitat and care for the basic needs of the crayfish. Our study of crayfish helps students develop a respect for all living things.” 

Having studied the life cycle and natural habitat of crayfish, the young, budding scientists created a comfortable environment for them in the classroom by placing them in freshwater containers. The students observed their behavior in certain situations to determine how crayfish adaptations work to help them survive in their natural habitat. Over the next several lessons, they will also identify different parts of their body and determine their gender, observe any changes over time, such as molting or shedding of exoskeleton and regrowth of lost appendages, and compare the structures and functions of crayfish to that of humans. 

“Nothing is more powerful than a hands-on learning experience,” Kennedy said. “When you are able to see, smell, touch, hear and interact with materials and organisms, learning is connected to a personal experience as opposed to something you have simply read about. To that end, recall of specifics and broader contexts of meaning and understanding are solidified.” 
                    
Following their study of crayfish, the students will continue the life science unit with a focus on the human skeletal system. They will explore joints and their role in movement, focusing on opposable thumbs before building operational models of muscle and bone systems to see how muscles move. They will also investigate their skin by making and analyzing fingerprint patterns.