This elementary project works well with younger children. You can use whole frozen squid from most fish markets or supermarkets. You will need to defrost them by soaking them in warm water shortly before you plan to use them --- no other preparation is needed. Place newspaper on all the tables to protect them and give each student a plastic plate and a squid. Students may wear plastic gloves and should wash their hands afterward. Students should examine the outside of the squid to identify the two tentacles, eight arms, hard beak, eye and siphon. Students should also look for dots of pigment on the squid's skin. These are the chromatophores, which allow the squid to change color. You may want to use only one squid, holding it up and asking students questions about it as you point out the external features.
This squid project can be used with elementary students of all ages. Elementary students can easily dissect a squid using toothpicks. They should carefully cut the squid open with safety scissors, along the ventral line of the mantle, and use the toothpicks to tease out the internal organs. For younger students, you can cut the squid open for them. Students should focus on the major organs, such as the heart, reproductive organs, digestive tract and ink sac. Less squeamish students may also want to dissect out the eye. Discuss with the students whether their specimen is male or female. Females will have a large white gland containing eggs in a jelly-like substance, lying on top of the other organs. Males will not have this organ. Males will have a white, fluid-filled sac toward the posterior of the mantle.
Drawing a diagram of a squid will help elementary school students to better understand squid anatomy. The younger students can draw the outside of the squid, making sure they include all of the features they can see. They should also label all of the features, such as mantle, tentacles and beak. Older elementary students can draw a picture of the squid anatomy as they dissect their squid. They can use colored pencils to denote the different organs and they should label all the organs they can identify.
The "pen" is a feather-shaped piece of cartilage that supports the mantle. Students can easily remove the pen by gripping it from the tail end and pulling slowly but firmly. The pen should slide out. Students can then dissect out the ink sac. This is a silvery-black organ connected to the intestines. Using scissors, students can cut open one end of the ink sac. If they press it gently with a toothpick, the ink will flow out. They can then dip the pen in the ink and use it to write with. For younger students, you can dissect out an ink sac and cut it open in a tank of water so the students can see how the ink spreads through the water. Discuss how the ink acts as a defense for the squid.