There many different kinds of squid that live in the mesopelagic zone. Some of them remain in that zone most of the time, perhaps like the giant squid or colossal squid. Others like the Humboldt squid may come closer to the surface a lot more, so we see them more often. But most of the mesopelagic squid are much smaller and come in wide variety of strange shapes. Most of them glow in the dark with bioluminscent organs. We don't know very much about the behavior of most of these squids in their dark, cold, deep environment that often has very little oxygen.