Sea spiders get their name from their vague similarity to "true" spiders. In a different class, sea spiders live in the ocean from shallow areas to thousands of meters below the surface of the water. Like other arthropods, they have a central body with legs around it. But, their bodies are tiny, with almost no abdomen and lots of appendages. Starting at the front end, a large proboscis with three lips is used to suck up food. Commonly, a stalk (tubercle) supports four eyes. Behind the proboscis may be long, clawed legs specialized for reproduction (ovigers). Males use them to court females and carry eggs. Walking legs come next and most sea spiders have four pairs but some have five or six. The walking legs are sturdy with eight joints, and each pair is on a separate body segment. Finally, at the tail end of a sea spider is an abdomen so small that it looks like a head and gives the spider the appearance of walking backwards.