What is the purpose of vibrant colors in deep-sea creatures?

[Medicago]

I have recently been to an exhibition of deep-sea life, some of the exhibited life forms live thousands of meters under the surface where sunlight does not penetrate, it is therefore that they rely entirely on geothermal vents as a source of energy, they have never been exposed to direct sunlight and neither, I suppose, did their ancestors. Looking at these creatures I couldn't help notice that, while some of them are entirely transparent and others are a bland shade of white or grey, as you'd expect in a light-less environment, there are a great number of richly coloured anemones and crabs. What is the purpose of this colour if there is barely any light to show it? Why would pigmentation develop in the first place?

 

[arildno]

Perhaps they are late-comers to the deepsea vents, and haven't shed their colours yet?

Interesting question, BTW

 

[Borek]

Could be their colors are random, after all, each substance interacts with a light this way or another. For example hemoglobin isn't red for a purpose, its color is completely accidental.

 

[schizoid]

... there are a great number of richly coloured anemones and crabs. What is the purpose of this colour if there is barely any light to show it? Why would pigmentation develop in the first place?

What kind of color ? Is it luminance like light producing creatures or pigmentation of skin ?
Do these still have eyes ?

 

[Borek]

I guess Medicago refers to pigmentation.

 

[Borek]

For some reason I have missed this phrase earlier:

some of them are entirely transparent and others are a bland shade of white or grey, as you'd expect in a light-less environment

Can you elaborate? Why do you think in a light-less environment any color should be preferred over others?

 

[schizoid]

I guess Medicago refers to pigmentation.

could you elaborate ? What is medicago ?

 

[Borek]

OP. That is, Original Poster. Person who started the thread.

 

[Monique]

Without having an example, it is hard to know what we are talking about. It could even be the case that organisms from the top-layer of the ocean adapted to living in the depths.

 

[schizoid]

OP. That is, Original Poster. Person who started the thread.

i got confused, I thought you were referring to some term . Forgot the OP was medicago.

 

[arildno]

Without having an example, it is hard to know what we are talking about. It could even be the case that organisms from the top-layer of the ocean adapted to living in the depths.

*Slap on monique's wrist for not crediting me with that idea. I was FIRSTEST!*

 

[Monique]

Oh, is that what you meant. And be careful with the slapping, I might slap back

 

[arildno]

My first post had a particularly poignant quality of clarity requiring a fine intellect to discern.

I will be more blunt&limpwristed in the future.

 

[Monique]

My first post had a particularly poignant quality of clarity requiring a fine intellect to discern.

If you say so
It appears that you haven't shed your colors yet either

 

[arildno]

It appears that you haven't shed your colors yet either

Actually, as the years go by, I'm acquiring new colours, rather than shedding them, for example a nice yellowing of my fingertips.

 

[Medicago]

Without having an example, it is hard to know what we are talking about. It could even be the case that organisms from the top-layer of the ocean adapted to living in the depths.

What kind of color ? Is it luminance like light producing creatures or pigmentation of skin ?
Do these still have eyes ?

No, it's not luminescent fish, specifically, I am referring to an Anemone with a red 'top', if you will, that lives exclusively around geothermal vents. Why would anything replace the sun for a geothermal vent over the course of evolution? I doubt it made it's way down from the surface.

Could be their colors are random, after all, each substance interacts with a light this way or another. For example hemoglobin isn't red for a purpose, its color is completely accidental.

I gave this some thought, it seems plausible, although sometimes the patterns and colours looked as if they serve/served some purpose at some point.