These animals aren't fish at all. Related to octopus, they're chameleons of the deep, able to change the color and pattern of their skin when they hunt, mate and hide.
Cuttlefish can shoot clouds of ink for protection. Long ago, this dark-brown ink, called sepia, was used for writing and drawing.
Cuttlefish have an internal shell called a cuttlebone that's divided into small sections. By filling these tiny compartments with gas, cuttlefish can hover above the ocean floor like submarines.
To catch dinner, this ocean trickster can put on an amazing display. Waving its eight arms and flashing a rainbow of colors, it lures shrimp, crabs and fish close, then grabs them with two long tentacles.