Make a Squid Print

Make a Squid Print

Grade Level

All

minutes

15 min - 1 hr

subject

Life Science

Activity Type: , ,

If you’ve ever seen a picture of a squid, you may have noticed that they have a bullet-like body. That streamlined shape helps them move quickly through the water and, in some cases, the air! There are more than 280 species of squid in the ocean. Different species share similar body plans and other features, but they also vary in ways that have enabled them to survive in a wide range of habitats.

Clawed armhook squid (Gonatus onyx) at 1328 meters. NOAA/Monterey Bay Aquarium Research Institute.
Clawed armhook squid (Gonatus onyx) at 1328 meters. Credit: NOAA/Monterey Bay Aquarium Research Institute.
Caribbean Reef Squid. Photo by Betty Wills, Wikimedia Commons.
Caribbean Reef Squid. Photo by Betty Wills, Wikimedia Commons.

 

Large red squid near seafloor. Pholidoteuthis adami. The red color serves as camouflage as the only light found in the depths of the ocean is blue. NOAA Okeanos Explorer Program, Gulf of Mexico 2012 Expedition
Large red squid near seafloor. Pholidoteuthis adami. The red color serves as camouflage as the only light found in the depths of the ocean is blue. NOAA Okeanos Explorer Program, Gulf of Mexico 2012 Expedition
A squid. Atlantic Ocean, Southeast U.S. shelf/slope area. 2004. By Andrew David, NOAA/NMFS/SEFSC Panama City; Lance Horn, UNCW/NURC - Phantom II ROV operator.
A squid. Atlantic Ocean, Southeast U.S. shelf/slope area. 2004. Credit: Andrew David, NOAA/NMFS/SEFSC Panama City; Lance Horn, UNCW/NURC – Phantom II ROV operator.
A spectacular deep sea squid (Mastigoteuthis sp.), known as a whiplash squid. NOAA OKEANOS Explorer Program , 2013 Northeast U. S. Canyons Expedition.
A spectacular deep sea squid (Mastigoteuthis sp.), known as a whiplash squid. NOAA OKEANOS Explorer Program , 2013 Northeast U. S. Canyons Expedition.

To us humans, squid may look both beautiful and strange. While you might expect to only see squid in the ocean, they’re a fairly common sight at grocery stores, fish markets, and bait shops, because people eat them and use them to catch fish. The species you encounter will differ depending on your location, but generally the squid we purchase as calamari come closer to shore for spawning and can live in depths up to 200 meters.

Longfin inshore squid ( Loligo pealeii ). Gulf of Mexico. SEFSC Pascagoula Laboratory; Collection of Brandi Noble, NOAA/NMFS/SEFSC.
Longfin inshore squid ( Loligo pealeii ). Gulf of Mexico. Credit: SEFSC Pascagoula Laboratory; Collection of Brandi Noble, NOAA/NMFS/SEFSC.
Humboldt squid (Dosidicus gigas) close up at 250 meters. By Rick Starr, NOAA/CBNMS.
Humboldt squid (Dosidicus gigas) close up at 250 meters. Credit: Rick Starr, NOAA/CBNMS.

A squid you won’t find at your local grocery story is the much larger Humboldt squid, which spends its days between 200 and 1,000 meters down in the ocean.

Look at the images of the squid above. What are the similarities? What are some of the most notable differences between them?

Using the Humboldt squid external anatomy sheet as a guide, identify the visible parts in the squid images above.

Although all squid species have adapted to their own ecosystems, you can use the common squid we find in the market to examine different structures that are generally present in squid anatomy. You can also use your examination to draw conclusions about how those structures relate to the life functions of that squid. Now, let’s observe a squid and use a squid print to catalog our findings!

Materials

PrintMaterials

  • 1 squid (should be obtained whole [i.e., none of the parts removed] from the fish market)
  • Ruler (necessary for math extension)
  • Hand lens (magnifying glass)
  • Squid print observation sheet
  • Humboldt squid external anatomy sheet (for guidance; note that the species you buy at the market will not be a Humboldt squid)
  • Paint (edible, watercolor, finger paint, etc.)
  • Paintbrush
  • Wax paper
  • Chopstick
  • Paper towel
  • Paper (printer paper, brown paper)

NOTE: Covering the table is recommended

  • Squid Observation

    Follow the steps to create observations for different parts of your squid.

    —To start, place your squid on wax paper.

  • Step 1

    —Use the Humboldt squid external anatomy sheet to identify the different structures of your squid.

  • Step 2 & 3

    —Examine the fins. What is the general shape of the fins? What do they feel like (floppy, rigid)?

    —Press down on different parts of the mantle. Describe the shape and stiffness on your observation sheet.

  • Step 4

    —Examine the suckers and rings on the arms and tentacles using a hand lens. Describe them on your observation sheet.

    Be sure to note any differences between arms and feeding tentacles.

  • Step 5

    Examine the skin of the squid from far away, and then with a hand lens. Write your observations down on your data sheet.

    Examine color, shape, size, arrangement, and iridescence.

    Squid skin has some interesting organs that help the squid camouflage. Learn more about those organs with this article.

  • Step 7

    Spread the tentacles and squeeze the area where the tentacles meet the body to reveal the beak. Examine the beak and write down observations on your data sheet.

Related Article

Playing Music Through a Squid

Create a Squid Print

You are going to create a print of your squid that shows the whole squid and its important structures. To create a print of the entire squid, you will have to paint in stages and arrange the squid parts so that the important structures are visible.

Follow the steps below to create your print.

  • Step 1

    To prepare your squid for printing, pat it dry with a paper towel.

  • Step 2

    Work with the top first, brushing the squid mantle and fins with a layer of paint.

  • Step 3

    Pick up the squid and place it paint-side down on your paper. Press down firmly on the sheet.

    You may need to smooth down the fins and slightly roll the specimen to get an accurate print.

  • Step 4

    Paint the mid-section of the squid (where they eyes are located), and place it on the paper paint-side down, below your mantle and fin section.

  • Step 5

    Paint the arms and tentacles one at a time, and press each one down to print them.

  • Step 6

    Paint the siphon, and then use the chopstick to stretch the siphon and press it down to create the print.

  • Step 7

    Let the print dry for 5-10 minutes.

  • Step 8

    Using your Humboldt squid external anatomy sheet as a guide, identify and label the parts of the squid on your print. Using your observation sheet, provide a description for each part.

  • Step 9

    After letting the print dry fully, snap a photograph. The print will continue to smell like fish, so you may not want to keep it around for long.

Squids are adapted to life in water. Looking at the list of basic functions below, see if you can connect the structures you examined with the functions they help the squid perform. Certain structures may be involved with more than one function.

StructureFunction

Squids4Kids gave us a closer look at both the external and internal anatomy of the Humboldt Squid.

Cephalopod Body Structures

I Cefalopodi viventi nel Golfo di Napoli (sistematica) : monografia by R. Friedländer & Sohn,1896. Public Domain
Illustration from I Cefalopodi viventi nel Golfo di Napoli (sistematica)

Squids, along with octopuses, cuttlefish, vampire squids, and nautili, are in a group of marine organisms called cephalopods. These organisms are soft-bodied and, except for the nautilus, do not have shells. You may be familiar with cephalopods because many species are experts at camouflage.

Although the body plans of other cephalopods are not the same as squids, they do have some similar structures. Using the images below, identify structures that are similar to the squid anatomy that you looked at earlier in the activity.

Squid. Photo by Klaus Stiefel
Squid. Credit: Klaus Stiefel.
Nautilus. Photo by Jessie Owens.
Nautilus. Photo by Jessie Owens.
Octopus vulgaris. Photo by Albert Kok at Dutch Wikipedia
Octopus vulgaris. Credit: Albert Kok at Dutch Wikipedia.
Cuttlefish found in Magic Point, Sydney. Photo by Klaus Stiefel
Cuttlefish found in Magic Point, Sydney. Credit: Klaus Stiefel.

 

What are the similarities in body plan? What are several major differences in body plan? Which of the cephalopods do you think is the fastest based on its body plan? Why?

As you can see from the range of body plans, cephalopods are a diverse class of organisms. A recent study found that cephalopod species have increased globally, which scientists think is due to their ability to survive in the oceans that are experiencing changes as a result of global warming.

Math Extension

Does the giant squid have a ridiculously large eye?

It may seem like this squid’s eye is way too big for its body, but believe it or not, it’s proportional! To draw this conclusion, scientists used allometry. Allometry is the study of biological scaling, where scientists examine the relationship between processes or traits that change together, referred to as co-varying biological measurements. For example, evolutionary biologist Julian Huxley looked at the relationship between claw size and body size in a male crab to examine whether the growth was proportional. He found that the claw actually grew at a faster rate than the rest of the crab body, resulting in what appears to be an exaggerated size.

Scientists have collected data on the proportion of mantle length to eye diameter for various squid species, such as the Humboldt squid and the giant squid. They found that, despite interspecies differences, the ratio was consistent among the 86 squid they tested. How does your squid stack up?

  • Step 1

    Using your ruler, measure the length of your squid’s mantle in centimeters (cm). Convert that measurement to millimeters (mm).

  • Step 2

    Using your ruler, measure the diameter of the eye. Convert that measurement to mm.

  • Step 3

    Calculate the Log10 coordinates using your squid’s mantle length and its eye diameter, using a scientific calculator and the equations shown.

  • Step 4

    Plot your mantle-eye ratio on the graph here to compare how your squid fits in with 86 other squid species studied.

    Graph Credit: Schmitz, L., Motani, R., Oufiero, C. E., Martin, C. H., McGee, M. D., Gamarra, A. R., … Wainwright, P. C. (2013). Allometry indicates giant eyes of giant squid are not exceptional. BMC Evolutionary Biology, 13, 45.

Why are we using a Log10 scale?

Logarithmic graphs, or log-scale graphs, are useful in organizing numerical data that varies widely in value. When graphing on a log-scale, the axes increase by a factor of 10 instead of by equal increments.

 

Want to learn more with cephalopods? Check out the Cephalopod Week spotlight.

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Xochitl Garcia is Science Friday’s education program assistant. She is a former teacher who loves hanging out with her fat-tailed gecko, which, despite the efforts of students, family, friends, and a fantasy football league to name it, is still only referred to as “the gecko.”

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