Sponges need a diet of fresh plankton, and they also need lots of space. You mustn’t keep them with fish species that feed on them or predator invertebrates. Urchins are fascinating, spiky ...

Plucking sponges from the reef prevents the glassy invertebrates from overpopulating and creates gaps in the reef where young corals can attach and grow. “Hawksbills are like the gardeners of ...