What's the meaning of the coin in the fish's mouth?

There's a story that always puzzled me where Jesus tells the disciples to catch fish that will have coins in their mouths to pay taxes with.  What does this story mean?

In this story, the tax collectors corner Peter and are asking why if Jesus pays the Temple tax.  Peter answers them that Jesus does.  Then Peter goes into the house and Jesus asks him who Peter thinks kings collect taxes from - their own children or others.  Peter answers him "from others" and Jesus responds that the children are exempt.  But, Jesus adds, so that the disciples don't cause offense, he instructs Peter to fish in the lake and that he will find a coin to pay the Temple tax in the mouth of the first fish he catches. 

A tax was established from the time of the Old Testament. Over time, this tax levied on Jews for the Lord's sanctuary was increased to pay for the upkeep and operation of the Temple.  In one sense, it's not that unusual that Peter will find the coin to pay the tax in the mouth of a fish.  There are plenty of stories in the Bible about unusual finds! Maybe Jesus causes this miracle of the fish because Peter is a fisherman.  And it's interesting that this is the only Gospel to tell the story - maybe because Matthew was a former tax collector himself.

What's more important in the story than where he finds the coin is the problem of whether Jesus’ followers should be paying taxes to support the Temple in Jerusalem. The disciples were facing a conundrum. If they believed Jesus was the son of God, why should he, or they, pay for the upkeep of what Jews considered God's house on Earth - the Temple.  Yet if they didn’t pay the Temple tax, they would no longer be considered Jews, an identity they didn’t intend to shed. Jesus solves the dilemma for them by affirming his identity as the son of God, and also extending his kingship to his followers, while protecting himself and Peter from still more confrontation with authorities and Temple tax collectors.