It's a special week. A new fish family has been discovered. You can view a movie of this primitive eel that lives in a dark cave at the base of a coral reef in Palau. Of course, there are plenty of other great images to check out. Thank you very much, as always, to everyone who contributed.
Dr Dave Johnson from the US National Museum in Washington just emailed me about an incredible eel that he and colleagues recently described. The fish, Protanguilla palau, is now classified in a new family, the Protanguillidae. It is one of the oldest eels (in evolutionary terms) known.
This week we feature footage of a 'very lazy' snailfish filmed more than 1 km below the surface. Sadly, we show yet another incidence of how innocuous-appearing litter can have disastrous effects on fishes. As always, thank you to all the people who have contributed images.