Jellyfishes live close to the shores of most oceans and spend most of their time floating near the surface. Jellyfishes have bell-shaped bodies that are between 95 percent and 96 percent water. They have a muscular ring around the margin of the bell that contracts rhythmically to propel them through the water. Jellyfishes are carnivores, subduing their prey with stinging tentacles and drawing the paralyzed animal into the digestive cavity. Jellyfishes are gelatinous—you can see through their bodies.