Cuttle Up 

What am I looking at?

This is a fluorescently stained embryo of a dwarf cuttlefish. Its eyes are yellow (1). Its developing muscles and nervous system are green (2). A subset of neurons in its brain, in two patches of epithelial cells in its mantle, and in its arms are red (3). Its “cuttlebone,” an internal shell that acts like a skeleton and helps it control its buoyancy, is purple (4). And the nuclei of all the cells are blue, making the remaining unlabeled tissue blue (5).

Biology in the background

Cuttlefish are cephalopods, like squid and octopuses. The term cephalopod comes from Latin words that mean “head” and “foot” – which is apt, since the tentacles of these creatures, which help them move throughout their environment, extend directly from their center, which is where their brain is.

Cuttlefish can change the color of their skin through a wide range of tones. They use this ability to camouflage themselves from predators, hunt from ambush, and communicate with other cuttlefish. They use special cells in their skin called chromatophores to change color. These cells have colored pigment in them that shows up as different colors depending on how densely packed it is within a given cell. There are tiny muscles in their skin that can expand or contract the chromatophores, changing the density of the pigment and therefore the color that they appear to be.

An adult dwarf cuttlefish can grow up to 7 centimeters long, or roughly three times the size of a human thumbnail.

Technique

This image was created using confocal microscopy.