Baby shells

Observe the size differences between young and old shelled animals.
Science content
Biology: Features, Adaptations of Living Things (K, 1, 3, 7)
Biology: Life Cycles (2)
Lessons activity is in
  • whelk egg case (or other baby shelled marine animals)
  • scissors to cut open egg case
  • box magnifier for each student
  • clear tape

Students are shown a marine snail egg case (e.g. knobbed whelk egg case containing tiny shells), found washed up on a beach (information and images).
An adult cuts baby shells out of the egg case. One shell is put in each student’s box magnifier.
Discussion of the shell shape: spiral, unlike the clams (and mussels) we have looked at before.
Students draw the spiral shell, filling a page of their notebook, to be as large as an adult shell. Tape the baby shell next to the adult, to compare the enormous size difference between baby and adult shells of this type.

Grades taught
Gr 1
Gr 2