A simple explanation and correction of the sentence: 'A whale’s favourite meal is tiny shrimp called plankton,' suitable for young learners.
The sentence you wrote is almost correct but needs a small change to be grammatically perfect.
Your sentence: A whale’s favourite meal is tiny shrimp called plankton.
Let's break it down:
A better way to say it is:
A whale’s favourite meal is tiny shrimp called krill.
Or, if you want to use plankton, you can say:
A whale’s favourite meal is tiny creatures called plankton.
So, depending on what you mean, you can pick one.
Also, if you want to say 'favorite' using British English, you write 'favourite' with a 'u' (which you did correctly!).
Summary: change 'tiny shrimp called plankton' to 'tiny shrimp called krill' for accuracy and correctness.