What happened when Albatross got his power in the novel, Darkstalker?

One day Albatross was playing with an empty clamshell. His sisters, Lagoon and Saphhire, came to see what he was doing. Sapphire tried to grab the clamshell from him and she mocked him. He yelled at her, and she took it away from him easily. Albatross does not know why he spoke to the shell, but he told it to bit her and bite off all her claws. The shell did as he commanded. That was how his power was discovered.