what is the possible allegorical significance of santiagos reaction to the shark

Santiago defends his fish with ferocity and abandon. He speaks to his fish like they are brothers. To Santiago, the killing of the Marlin was a communion. Santiago speaks to the dead fish as he fights off the sharks. It is as if Santiago is defending the honour of his brother. Santiago feels the Marlin has let itself be slain to a man worthy of the kill. I'm not sure if there is a specific work this is allegorical with but certainly the old man treats this as a battle not only for his catch but for the honour of his catch as well.