What is the symbolism of the octopus Montalbano is given in the opening pages of the novel, A Voice in the Night?

The octopus given to Montalbano at the opening of the novel symbolizes the far reach of the mafia over the city. Just as the octopus has tentacles, the power of the mafia reaches in multiple directions, causing corruption. Montalbano continues to consume the octopus throughout the novel, representing the way in which he works to defeat the corruption in the city.