[Coral-List] Coral fluorescence

[Barbara Gratzer]

Dear all,

Since I have not received any answers yet, I will try to resend the
questions I came across lately:

1. I thought corals possessing colours have many GFP like proteins.  Now I
have discovered several acroporid finger-corals with purple colour that are
not fluorescent. Do you know why? Does GFP like protein not necessarily
mean they are fluorescent or does the colour derive from other proteins?
And why do some colours not possess colouration but are highly fluorescent
in contrast to others?

2. What's exactly the purpose of being fluorescent. I know the pigments
causing fluorescence are thought to act either as protection from
stress/sunlight or as enhancer for symbiodinium to increase photosynthesis,
but is it just a coincidence that they are fluorescent at the same time? I
dont understand the correlation.

3. Whats the purpose of different fluorescent light levels? Most of the
corals emmit green and yellow light and very few emmit red light. Is it
caused by the proteins or does it have something to do with different
photosynthetic active pigments?

4. Within our coral nursery I have come across several Acropora species
(especially purple coloured) that lost their original colour after being
transplanted and only had a bright brown colour after 6 month. Is that a
process caused by stress? Whats the purpose?

Thanks in advance for your answers!

Warm regards,

Barbara Gratzer MSc
~~~ Σ^^°> ~~~
Resident Marine biologist
Huvafen Fushi Resort
Republic of Maldives