Science in Pajamas: Swimming Squid


Squid, which are similar to the octopus, have eight arms and two tentacles. The arms, called cephalopod limbs, resemble those on an octopus with suckers along their length. The two extra tentacles have suckers only their ends, and are meant to capture food such as fish and crabs.


Its powerful muscles contract to force out jets of water that propel it in the opposite direction that they’re facing - so it swims backward in a zigzag formation. As a strategy to avoid predators, it can shoot out an inky fluid made from melanin particles called sepia that creates a dark cloud, allowing it to create a diversion and flee to safety.


See the quick movements of a squid for yourself with a homemade creation!


What you'll need:

  • balloon

  • water

  • squirt cap (the type that comes on sports drinks works well)

  • bathtub

Instructions:

Fill the bathtub with water. Then, fill the balloon with water, and while you keep the neck pinched closed, have a friend stretch the lip up over a closed squirt cap. Hold your balloon “squid” underwater one end of the tub or sink, open the cap nozzle, and let go. Water will shoot out of the bottle and propel the balloon in the opposite direction - mimicking a real squid!


If you're interested in the detailed physics behind this movement, here's a great resource.

Resources and References:

  • Littlefield, Cindy A. Awesome Ocean Science: Investigating the Secrets of the Underwater World. Williamson Books, 2006.

  • Zych, Ariel. “Jet Propulsion Locomotion of Squid and Octopus.” Science Friday, www.sciencefriday.com/educational-resources/jet-setting-cephalopods/.

  • Watson, Stephanie. “How Squid Work.” HowStuffWorks, HowStuffWorks, 1 June 2007, animals.howstuffworks.com/marine-life/squid2.htm.


Featured Posts
Recent Posts
Archive
Search By Tags
Follow Us

Subscribe for Updates

ADDRESS

500 Discovery Parkway

Redwood City, CA 94063

info@sfbaymsi.org

Tel: 650-364-2760

Click here for directions

facebook fish logo.png
instagram.png
Twitter fish logo.png
linkin.png

Marine Science Institute is a tax-exempt 501(c)(3) not for profit organization. Federal Tax ID# 94-1719649

© 2020 All Rights Reserved  

Inspiring respect and stewardship for the marine environment through experiential learning

Thank you to our generous supporters who donated more than $25,000
kabcenell_logo
westpoint harbor
noaa1
Bohannon Foundation
Morgan Fam Fdn
HSF_logo_horiz_RGB_large crop 4
lesherlogo
JVLF Logo