This activity explores images of the bobtail squid, which serve as phenomena for learning about symbiosis and interspecies interactions.
The Hawaiian bobtail squid has a pouch inside its body called the light organ, which hosts bioluminescent bacteria such as Aliivibrio fischeri (formerly Vibrio fischeri). The relationship between squid and bacteria is a classic example of symbiosis. The squid provides the bacteria with food and shelter, and the bacteria emit a blue light that hides the squid from predators and prey. These images include a photograph of a bobtail squid and a picture of a squid’s light organ created from a video-microscopy recording.
The “Educator Materials” document includes background information and implementation suggestions for using the images as phenomena. The “Student Handout” includes the images and background information.
“Light Organ” image by Janna Nawroth, Research & Development, Emulate, Inc.
Student Learning Targets
Examine images of phenomena, make observations, and ask questions.
Collaborate with peers on ideas, ask questions that require higher levels of reasoning, and develop deeper understanding of concepts.
Explain the concept of symbiosis.
bacteria, bioluminescence, camouflage, cilia, counterillumination, host, marine biology, microbe, microscopy, mutualism, symbiosis
McFall-Ngai, M. “Divining the Essence of Symbiosis: Insights from the Squid-Vibrio Model.” PLoS Biology 12, 2: e1001783. https://doi.org/10.1371/journal.pbio.1001783.
Accessibility Level (WCAG compliance)
AP Biology (2019)
ENE-3.D, ENE-4.B, IST-5.A; SP3
IB Biology (2016)
AP Environmental Science (2020)
Learning Objectives & Practices: ERT-1.A, SP2
IB Environmental Systems and Societies (2017)
Common Core (2010)
Vision and Change (2009)
CC2, CC5; DP1