These include crabs, molluscs, sea urchins, starfish and polychaete worms. Clams, periwinkles, crabs, shrimp, starfish and sea urchins are found on most beaches. Invertebrate predators include crabs, starfish and octopuses. Globotruncanid Foraminifera and echinoderms such as sea urchins and starfish (sea stars) thrived. Common oyster predators include crabs, seabirds, starfish, and humans. Sea urchins use their tube feet to move around in a similar way to starfish. Tide pools provide a home for hardy organisms such as starfish, mussels and clams. Large outbreaks of these starfish can devastate reefs. Starfish and other echinoderms are sensitive to marine pollution. Brittle stars or ophiuroids are echinoderms in the class Ophiuroidea closely related to starfish. The larvae of several species of starfish can reproduce asexually before they reach maturity. Fertilizers also increase the amount of phytoplankton available for the crown-of-thorns starfish larvae to consume. Recovery has been shown in after storm disturbance and crown of thorns starfish invasions. Some species of starfish can regenerate lost arms. Saponins seem to occur throughout the lifecycle of the crown-of-thorns starfish.