A sea leopard behind a curtain of plankton. Like all sea mammals, sea leopards are curious, says photographer Bill Curtsinger. But they can also be dangerous.

• 一只海豹躲在浮游生物的幕面。摄影师比尔·钦格说，像其他海洋哺乳动物一样，海豹非常好奇，但同时也具有危险性。