On top of its head, the sea spider has a knobby projection bearing two, three, or four simple eyes. The head ends in a snout with a sucking mouth. Sea spiders feed by sucking the body juices of such marine animals as sea anemones, sponges, and sea squirts. They prefers a liquid diet which they eat standing up. They insert their long proboscis into their prey, sucking up the nutrients.
Most sea spiders eat other animals and attack invertebrates (in-VER-teh-brehts), or animals without backbones that are attached to the ocean bottom, such as corals, clams, and marine worms. A few species feed on red algae (AL-jee), a special group of plantlike ocean life that lacks true roots, stems, or leaves. Other sea spiders feed on bits of plant and animal tissues that build up under colonies of invertebrates.
Picture Credit : Google