Objectives:
Students will leave the class knowing more about the unique properties of shark skin and understanding the electroreceptive ampullae in sharks and how they use it to sense prey.
*IMPORTANT NOTE* In the class description, encourage students to come to class with a random fact about sharks. (It can be whatever type of shark they choose. Anything from Zebra sharks to Hammerheads.) They will share their shark fact during the introduction part of the class.
Materials:
Visual aids (images of shark skin, ampullae structures)
Video clips showcasing shark skin and other characteristics
Theocratic Connection Links:
Video Links:
- WAS IT DESIGNED? – The Shark’s Skin
- How Sharks Use Electricity To Sense Prey:
- Shark skin feels like sandpaper and it hurts:
Introduction (7 minutes):
Begin by introducing sharks as fascinating and highly adapted marine predators.
Present the two main topics for the class: the properties of shark skin and the electroreceptive abilities of sharks.
Allow each student to present the shark fact they’ve prepared to share with the class.
The Remarkable Properties of Shark Skin (10 minutes):
Show an image or video of shark skin up close to illustrate its texture and structure. Explain how shark skin, covered in tiny grooved scales called dermal denticles, feels rough like sandpaper when touched from tail to head.
Discuss the two primary functions of these scales:
Reduced Water Resistance: The grooves channel water, allowing sharks to swim with minimal drag.
Parasite Prevention: The scales flex, creating an unstable surface that prevents parasites from attaching.
Highlight the possible applications of sharkskin properties in human technology:
Swimsuits: Sharkskin-inspired swimsuits can increase swimming speed by reducing drag.
Transportation: Potential developments in reducing friction drag for cars and boats.
Medical and Environmental Uses: Microbe-repellent coatings for boats and medical devices to reduce hospital-acquired infections.
Facilitate a short discussion with students on other potential uses for sharkskin-inspired technology.
How Sharks Sense Prey (10 minutes):
Introduce the concept of electroreception and its importance for sharks in locating prey. Show an image or diagram of a shark’s head highlighting the ampullae of Lorenzini (the pores visible on their snouts).
Explain how electroreception works:
Active Electroreception: Sharks use their own electric current to sense their surroundings.
Passive Electroreception: Sharks detect electric currents produced by other animals to locate prey.
Ask students a review question to make sure they understand:
“What are the dots on the sharks?” (Answer: Pores connecting jelly-filled tubes to bulb-like structures called ampullae)
Ensure that students understand the process of how the sharks electroreception works:
1. Electric current is detected by the pores.
2. The current travels through jelly-filled tubes to the ampullae.
3. The ampullae send signals to the nerves.
4. The signals are processed by the brain, allowing the shark to detect prey.
Conclusion (3 minutes):
Summarize the key points about shark skin and electroreception. Reinforce the importance of these adaptations in the shark’s survival and hunting efficiency. Encourage students to think about the broader implications of these adaptations in technology and medicine and how the shark’s design glorifies Jehovah.
Assessment: Assess student comprehension and engagement through active participation in discussions and thoughtful responses to reflection questions. Evaluate students’ understanding of shark skin properties and electroreception through their responses to questions and the quality of their participation in activities.