It's a little overwhelming to think how little we humans know of marine life. The earth is two-thirds water and yet we've only explored 5% of that.
Recently, scientists from the NOAA Okeanos Explorer Program sent a remote operated camera deep into the ocean off the coast of Puerto Rico. Some of the species of marine life they saw on their screens were so new, they didn't even have names for them.
Check it out.
Source - Quartz