Thursday, October 16, 2008

Octopus, a master of disguise

The only time I saw an octopus while I was on vacation in Coral Bay was in "The Lagoon" a snorkeling site north of the bay.

Of course I could only count myself lucky to have spotted it. It was partly hidden in a burrow that was less that a meter from the surface when I first found it. By estimation, the animal's head was 15 cm across.

Look at the photos and you will agree that the octopus is indeed a master of disguise, one who is capable for changing its colors and texture to blend into its background.

Special skin cells called chromatophores, which contain sacs of pigments, are responsible for the octopus' capability to change its colors quickly. An adult octopus may have as many as 2 millions of these cells. By contracting or stretching the sacs of pigments in those cells, the octopus can change its colors very quickly. The same mechanism occurs in the cuttlefish and squid too.

Color change doesn't just help the octopus blends into its surroundings, it also reflects the animal's mood, e.g. fear, aggressiveness and sexual arousal.

It later moved to another burrow but stayed there long enough for me to snap a few more shots.


Mosura said...

Pretty amazing. I've only ever seen an octopus about a half dozen times. I was watching a Blue-ringed octopus last year. It was in just a few cm's of water. It tucked itself into a little crevice and when the blue rings disappeared you could no longer see the octopus at all.

Robert said...

I am loving this blog.

My GF and I took up snorkling at the early this year.

We've managed to spot an octopus a couple of times at Mettam's Pool.

Tsun-Thai Chai said...

Thanks, Robert. And I envy you - I don't remember ever seeing an octopus at Mettams Pool. Did you have to go really deep when you spotted it?

Robert said...

The first one we saw was in ridiculously shallow actually! Like only a couple of metres in. It was a bit rough that day, so maybe it got washed in?

The second time was a little further out, but not too far (Jessica my partner is still a little timid). We had just discovered our first (and only so far) stingray (a ray of some kind, I'm not too good at identifying them yet) and sitting behind him was an octopus.

The two octopus sightings took place within two weeks of each other, and since then we have pretty much only seen fish.

We haven't ventured outside of Mettams Pool yet, thought.