“They’re all colors, Derek,” Uncle Charlie told him. “Actually, the black ones aren’t as valuable as the white. They’re valuable, all right, especially if they’re perfectly matched, as those two your father sent us were.”
“I’d feel a lot more certain that we’d found the right place if we found some black ones.”
“Let’s go back down when we finish these oysters,” Biff said.
“Funny thing about sharks,” Uncle Charlie said. “Although they are the pearl diver’s greatest enemy, they can also help produce the pearl.”
“The best pearl is the perfectly round pearl. The foreign body which gets into the oyster must be perfectly round to produce the perfect pearl. These round objects are the eggs of parasitic worms. The adult worms are the parasites of sharks.”
“So where you find sharks, you can find pearls?” Biff asked.
“Not exactly, Biff. What I mean is this: where there are pearl fisheries, the perfect pearls come from the eggs the shark’s parasites lay.”
No more pearls were found in the batch dug that morning. It was growing late in the afternoon. They decided to go back to the morning’s site, and if no sharks were in evidence, they’d try half an hour’s diving.
They returned to the same site. Biff and Derek went overside. Before they started scooping up oysters, they made sure no sharks were around. Biff loaded one basket and sent it up. He saw Derek send one up. Biff filled another. He looked at his watch. They’d been down twenty minutes.
“One more basket,” Biff said to himself, “and we’ll call it a day.” He turned in Derek’s direction to signal to him that this was the last basket. Roiling water ahead pushed an alarm button in Biff’s mind. He increased his speed.
Derek was being attacked savagely by giant band shells. They swarmed around him, slashing at him with their claw-shaped, horny shells.
Biff whipped out his knife and shot into action.
The giant band shells, many times the size of the ordinary conch shell, are the only known shell fish to attack human beings. They have a tough, scimitar-shaped muscle which they use as a door to close the opening at the large end of the shell. While other conches use this muscle only as a door, the giant band shell uses it as a weapon. The end of the muscle is hooked and razor sharp. The giant band shell springs at a man, using a second muscle to propel itself, then slashes and cuts with its “door.” In moments, it can cut a man’s body to shreds.