Sea urchin
Sea urchins or urchins () are typically spiny, globular animals, echinoderms in the class Echinoidea. About 950 species live on the seabed, inhabiting all oceans and depth zones from the intertidal to . Their tests (hard shells) are round and spiny, typically from across. Sea urchins move slowly, crawling with their tube feet, and sometimes pushing themselves with their spines. They feed primarily on algae but also eat slow-moving or sessile animals. Their predators include sea otters, starfish, wolf eels, and triggerfish.
Fauna of the United States
In Hawaii, three species of sea turtles are considered native: honu, honu’ea and the leatherback sea turtle. Two other species, the loggerhead sea turtle and the olive ridley sea turtle, are sometimes observed in Hawaiian waters. The Hawaiian green sea turtle is the most common sea turtle in Hawaiian waters. As well as turtles, the sea life consist of more than forty species of shark and the Hawaiian spinner dolphin is widespread. Hawaii's coral reefs are home to over 5000 species, and 25 percent of these are found nowhere else in the world.