Best of Mike #511

On our dive trip earlier this year we had a lot of Octopus encounters. In fact, we may have had more interactions on this trip than the sum total of all of our other octopus encounters… ever.

I recently heard that the energy needed to change colors is considerable… which motivated me to learn more about what and how they are doing with these color changes.

So here’s what I learned…

Octopuses change color for camouflage, to communicate with other octopuses, and to match their mood.

The color changes can occur in a fraction of a second… sometimes under 100 milliseconds.

They can change color by stretching or squeezing millions of elastic cells called chromatophores under their skin.

Each chromatophore contains a sac filled with pigment that can be red, orange, brown, yellow, or black. When the muscles around the chromatophore tighten, the sac opens, revealing more pigment. When the muscles relax, the sac contracts, making the octopus appear white.

Best of Mike #510

This little guy, usually about 3-4in long, is a Green Razorfish.

His most distinctive feature are his eyes… made up of a bright red iris with a green pupil.

They are generally wary of divers… keeping their distance by moving away as you approach.

If they decide you are a big threat… they will dive under the sand and stay hidden until you move away.

Best of Mike #509

The Pedersen Cleaner Shrimp has a transparent body and legs that are covered with purple to lavender spots and two long, white, hair-like antennae.

They live in association with a variety of different anemone… you can see Corkscrew Anemone in the background of this pixture.

They are one of the cleaner shrimp… and will sway their bodies and wave those long antennae to attract customers. 

In fact, if a diver is gentle in their approach with a bare hand extended… these shrimp may swim out and attempt to clean fingers.

Best of Mike #508

Many fish have the ability to change their coloring in order to blend in with their surroundings.

I thought you might enjoy seeing that for yourself.

These two pixtures are the same fish, a Honeycomb Cowfish… taken just seconds apart as he swam across the reef.