Starfish (Sea Stars)
There are more than 1500 species of starfish, which are also called sea stars. They come in a variety of colors, from bright orange to blue to pale pink to brown. Many of them have the typical echinoderm pattern, with five radially symmetrical sections, each sprouting one arm, or ray. Some species, though, have more than twenty arms. Some species, like the crown-of-thorns starfish, have bristles and bumps on their arms. The bristles can produce a dangerous venom, so it pays to be careful around any bristly types you find at the shore.
Most starfish eat clams and other bivalves. To manage this, the starfish forces the clam’s shell open with its strong arms. As soon as there’s even a narrow opening—say, one millimeter wide—the starfish turns its stomach inside out and thrusts it through the crack. The stomach then uses acid to begin digesting the clam. It soon weakens and the starfish is able to open the shell fully. It pulls its stomach back into itself and swallows the clam. Starfish may also eat various other small animals, such as snails, corals, worms, and sponges. Some species eat carrion and even feces.
--from Cabinet of Curiosities
Photography by Dee Puett