Science Crab, Plankton, Light Claim

In my science class, we just finished up our unit on light waves. During this, we learned about the different types of light, the wavelength, and about skin cancer around the world. As closure to our unit, my teacher made us write about whether we think a crab can or cannot see the plankton it eats. We had evidence cards to guide us and to use as resources.

The crabs cannot see the plankton they eat. According to Evidence Card E, orange fish, when closer to the surface of the water, a species of fish are seen and appear a bright orange color. However, closer to the floor of the ocean, they are nowhere to be seen, the visible light color does not transmit far enough for the fish to reflect the orange. Also, based on Evidence Card D, the same is with all of the other visible light colors, none travel far enough to reach the base of the ocean. Without any light reaching that far, the plankton do not reflect any color, and cannot be seen. Based on all of this, according to Evidence Card A, the crabs are not able to see the plankton they eat, as there is no visible light that reaches their eyes. Some may believe the crabs ARE able to see the plankton, due to the fact that the algae are able to absorb visible light, and can reflect the green light. However, the algae "live" and float in a higher area compared to the plankton. Even though the plankton eat the algae, none of the light is transferred into the plankton, which still proves that the plankton are not visible to the crabs.