Here is a link to an article that talks about the recently found species of jellyfish in the Mariana Trench: http://www.smithsonianmag.com/smart-news/deep-sea-researchers-spot-mysterious-jellyfish-near-mariana-trench-180958961/?utm_source=facebook.com&no-ist
Here is a live-stream of the expedition that led to the discovery of this jellyfish (off topic, but live streams are pretty cool! :D): http://oceanexplorer.noaa.gov/okeanos/media/exstream/exstream.html