This guy came out of the booth to gift us a crab. What a friendly dude!
Water tends to absorb light in the red portion of the visible spectrum, often giving the subjects of underwater marine photography a blue-green tint that can wash out their natural colors.
The yellow bioluminescent ring on this female octopus (Bolitaena pygmaea) may attract mates.
In nature, it is quite rare to encounter octopi with extra tentacles (or "arms," for the purists), but a pair of aquariums in Japan's Mie prefecture have some extraordinary specimens on hand.