Sea urchins, which feed mainly on algae, live in environments that alternate between species-rich kelp forests and sea urchin-dominated barrens.
Sea urchins, which feed mainly on algae, live in environments that alternate between species-rich kelp forests and sea urchin-dominated barrens.
海胆，主要以藻类为食，它决定着环境是成为品种丰富的海藻森林还是海胆遍地的“荒原”。