This lesson focuses on the diffusion of gas molecules across the cuticle membrane of sea spider legs and the role body size plays in the ability of sea spiders to uptake gases. Students construct model sea spider legs of varying diameters and use them to investigate the relationship between surface area-to-volume ratios and diffusion.
Using photos from a variety of websites, including the PolarTREC and SCINI websites, students will identify organisms to phylum and/or class level (e.g. polychaetes, starfish, brittle stars, sponges) and then research the primary foods that these organisms eat. They will then develop a simple food web for these organisms.