The ice worms, as they are known, were found at a depth of around 500m. While this depth is nothing too strange, many things live at this and far greater depths, it was the habitat and food source that interested the scientists the most.
The ice worms live on a structure called a "hydrate", which is essentially a frozen block of methane gas. The methane bubbles up from the floor of the ocean and, owing to the pressure and temperature, the gas freezes. Mixed into the frozen gas is a family of bacteria that feeds off the hydrocarbons in the gas. It's these bacteria that attract the ice worms, as they provide a food source.
The small pink worms spend their entire two week life digging a small hollow into the methane ice to gain access to the bacteria. They then reproduce and die, leaving their offspring to carry on the cycle.
Strange creatures indeed.
