Originally Posted by
Taigu
A quick go at answering your question:
The mokugyo has the shape of a fish because a fish even when dead has open eyes, and thereore it symbolises awakening. It is uses solely to give the rhythm of sutra when we chant.
The wood has also often the shape of a fish but this time the fish has a pearl in his mouth, practice ( zazen) and the treasure of awakening ( the pearl) are one, it is used to call people to the Zendo to sit. Striking more rapidly is also a way to convey that time passes quickly and one has to not procrastinate.
The drum gives the time when priests are sitting.
(...)
But I am sure Jundo will have many more things to share with us.
Gassho
Taigu