Comparing physiologies: Giant Pacific octopuses
Fun Fact
The giant Pacific octopus has three hearts, nine brains and blue blood.
Introduction
When I was young, my father told me that my tummy rumbled because I needed to power my engine by eating. I confess I thought that a small steam train was doing loops inside me. It either says a lot about my imagination or a lot about my Dad’s level of persuasion!
Children can have some interesting perspectives on what is inside them. Cultural perceptions can also make a huge difference. Why not investigate their prior knowledge by starting a conversation about the biology of the Pacific octopus or another sea creature they have studied?
Where to start
The Pacific octopus is a fascinating creature. Learn about its anatomy and life with the children. You can use this approach in numbers:
1 Pacific octopus
2 eyes
3 hearts
4 years – their average lifespan
5 metres – the biggest is nearly 5m long
6 months – a Pacific octopus mum watches her eggs for half a year
7 clams for afternoon tea
8 arms
9 brains
How is the Pacific octopus different from us? The children can start to compare their own anatomy to that of the octopus by investigating their own bodies: Where do they think their heart is? Can they feel it beating? What does it do? What colour is their blood? Where is their brain? How tall are they? Why do they think they have two eyes? Can they think of an animal that has more than two eyes? Imagine if they had a brain in each of their legs! What would that be like? This is also a great way to assess their prior knowledge.
What’s the STEM?
The children are comparing their physiology to that of a sea creature and become more aware of how their own body functions.
Interesting facts for adults
The giant Pacific octopus is a cephalopod, which is Greek, meaning head foot. Octo means eight, relating to its eight arms. Based on observations, octopuses use two of their limbs like legs and only six like arms. Despite the joke, “How do you make an Octopus laugh?” – Give is tentickles,” it is incorrect to call its arms tentacles!
Each of its arms has its own brain that controls movement. It allows them to work individually but still function as a whole. It also has a central brain that controls the nervous system. That’s nine brains total! They are very clever and can open jars, mimic other octopus species and tackle mazes.
They live for up to four years. A pacific octopus mum watches her eggs (up to 74,000) for seven months without eating or leaving the crevice in which she laid them.
Observations, conclusions and extensions
What other animals have you investigated with the children in your care?
Share your experiences using the comments section below.
Article author: Hayley Bates
National Certifications Coordinator
Hayley has an insatiable thirst for learning – about everything! Her sheer joy of discovery and passion for professional development makes her the perfect person to run the Little Scientist’s House Certification program.
