Make a sea potato
Have fun making a model of a sea potato and add it to your seabed in a box if you are making one.
Ages 5+
15+ minutes
Part of:
Convex Seascape SurveyEnjoy exploring seabed life by making a sea potato out of plasticine. Sea potatoes or common heart urchins are a type of sea urchin that burrow into the seabed. They are covered with spines and have lots of small legs underneath to move and feed.
Activity steps
Step 1
Make the overall shape of the sea potato by taking a 6 cm ball of modelling clay and shaping it like a heart.
Step 2
On what will be the bottom make an indent with your thumb to represent where the mouth would be. In nature, all sea urchins have a hole in their hard shells at the bottom for their mouth and one on top for their anus, with the soft organs in the middle. You could add a dimple on top for this last feature!
Step 3
Sea urchins have a five-fold symmetry which you can draw on the surface with a toothpick or modelling tool.
Step 4
Make the spines by rolling small sections of modelling clay and adding these to the surface of the overall shape.
Step 5
You can add tubular feet too using a different colour of modelling clay.
Step 6
Complete your sea potato by adding neon paint especially near and around the mouth area to show how the sea potato eats organic material in the sand.
Safety guidance
- Make sure that children wash their hands thoroughly after using the modelling clay and paint.
- Work on a non-stick surface.
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