Science is a journey full of surprises and the story behind the current interest in coral fluorescence and pigmentation is no less full of twists and turns. This tale is one of the reef-keeping hobby in Russia and Japan, a couple of fortuitous laboratory accidents, a revolution in biomedical research, revelations and fortunes made, discovery of a new symbiosis, as well as the small contributions of reef hobbyists from other parts of the globe. While coral coloration is today less likely to be the subject of intense interest (and debate) within the hobby than it was just 5 years ago, the situation is much different in peer-reviewed literature, with researchers producing a staggering amount of information on marine invertebrate fluorescent and non-fluorescent pigments. It is estimated that 26,000 papers mentioning fluorescent proteins will be in print by the end of 2006. Not all of these – few, in fact – are of much interest to the advanced aquarist, however, some offer glimpses of those conditions required to activate, or inactivate, the vivid coloration we sometimes see in our captive reefs. Of course, explaining pretty colors in an aquarium (or reef) is not usually researchers’ main goals. The revolutionary use of certain proteins as molecular markers (or ‘highlighters’) in the biomedical field has driven the identification, refinement and genetic modification of many ‘wild type’ fluorescent proteins. Other researchers have studied coral pigments in order to remotely sense (by aircraft or satellite) the light reflected and fluoresced by natural reefs. In this manner, vast tracts of reefs can be examined in relatively little time and an assessment of reef health can be made.

Why should reef hobbyists concern themselves with fluorescence? Isn’t it generally accepted that light energy is a prime requirement for expression of coloration? What if could understand and anticipate responses of a pigment to different visible light bandwidths, ultraviolet radiation or other stimuli? What of the effect of nutrients and supplement additions (such as iodine)? Not all pigments are fluorescent but all are selective in the wavelengths they absorb or reflect. With the recent introduction of relatively inexpensive spectrometers (such as those from Ocean Optics or Edmund Optics) more hobbyists can gain access to these powerful tools (for a review of the Ocean Optics spectrometer, see Riddle, 2006). An understanding of fluorescent proteins (at least their excitation and emission peaks – see definitions below) is essential for understanding the apparent color of corals, since fluorescence can influence the color perceived by the observer. Further, understanding of fluorescence and its effects is essential when we examine reflected light later in this series. Realizing the potential reasons for color transitions of our captive corals might enable us to see these shifts as environmental indicators, good or bad. But, perhaps most importantly to us as hobbyists, manipulating the artificial conditions with aquaria might allow us to alter pigmentation within certain invertebrates and create animals with ‘customized’ coloration.

This modest series of articles will review some recent conclusions drawn from experiments from the world’s leading authorities on fluorescent and non-fluorescent pigments. When possible, recommendations of areas for further investigation by hobbyists will be suggested. Observations by hobbyists can be of great use. It is difficult to ignore mountains of anecdotal evidence – it has been generally accepted within the hobby that light is sometimes a critical factor in promotion of some coral coloration.

In 1995, hobbyist (and scientist) Craig Bingman was perhaps the first to recognize that the rainbow of colors in marine invertebrates shared a common ancestor in a green fluorescent protein; an addendum followed in 1999. All observations have not proven prophetic – it was once very popular within the hobby to associate all coral coloration with pigments found within zooxanthellae. While it is true that light absorbed by the photopigments of symbionts does play an important part in the overall coloration perceived by the human eye, it is generally a mistake to ascribe fluorescence to chlorophyll and a definite error to link it to peridinin, beta-carotene and some other photopigments (the role these pigments play in determining the apparent coral color will be examined in a separate article. Phycoerythrin is a notable exception as it can lend an orange fluorescent color to corals under proper conditions). Articles that state differently-colored zooxanthellae are responsible for fluorescence are misleading. In the same vein, coloration was wrongly attributed to natural sunscreens that absorb and mitigate the effects of damaging UV radiation. By extension, the idea was formed within the hobby that ultraviolet energy is necessary for colorful corals (we know now that these sunscreens – MAAs for mycosporine-like amino acids – are colorless and do not lend color. We’ll examine in this series the recent evidence for the necessity of UV in color shifts and relate this to aquarium husbandry practices).

Peer-reviewed publications have not always been correct either. For instance, Kennedy (1979) described colorful invertebrate pigments as porphyrins (naturally abundant in plant and animal tissues. Porphyrin is a Greek word meaning ‘purple’ – they are chromatic pigments). Kennedy reviewed early work by Moseley (1877) which describes the red pigment found in Discosoma, Actinia, Flabellum, Stephanophyllia and Fungia as ‘polyperythrin’ with excitation wavelengths in the yellow-green portion of the spectrum.

Red fluorescence found in stony corals Montastraea cavernosa and Mussa angulosa tempted Kennedy to describe them as porphyrins as well. Even with missteps the pieces of the coloration puzzle are slowly but surely falling into place.

For general interest articles examining coral fluorescence in aquaria, see works of Riddle and Amussen (1998), Delbeek (2003), Calfo (2005), Blundell (2005), Finét and Lesage (2005) and Credabel (2006). Interesting comments concerning a few specific fluorescent pigments can be found in Delbeek and Sprung, 2005, as well as in Tyree (1998). Charles Mazel maintains a fascinating website on marine fluorescence at www.nightsea.com.

My fascination with coral pigments began when I saw a blue-tipped Acropora (formosa?) specimen. This was in the early 1990’s, and many hobbyists (including myself) were of the opinion that it was practically impossible to artificially over-illuminate an aquarium containing stony corals such as Acropora. So, I was very curious why a coral would reflect light energy necessary for photosynthesis (the coloration did not appear to be fluorescent). I did not know it at the time, but this simple observation would be a turning point in my life. I’m still unsure of the reason why that Acropora fragment reflected blue wavelengths, but my fascination would become a passion in the quest for answers about coelenterate coloration.

The first in this series will present information on a few of the fluorescent proteins found in marine invertebrates. Generally, fluorescent proteins are best viewed under relatively narrow bandwidths, such as those produced by actinic and black lights. However the mere categorization of ‘fluorescent’ and ‘non-fluorescent’ proteins presents difficulties – a protein can be fluorescent in a technical sense but the ‘glow’ may be of low intensity and invisible to the unaided eye. In addition, environmental conditions (such as light quality and/or quantity or chemical changes) may trigger a mutation of a non-fluorescent protein to a fluorescent species or vice versa. This leads us to a point where some definitions are in order before we continue.

Fluorescence. Fluorescence is a phenomenon in which a material absorbs light of one color (wavelength) and emits it at a different color (wavelength). Absorption occurs when an incoming photon (light particle) causes an electron to move from a stable ground state to a higher energy, unstable excited state. One of the ways for the excited electron to return to the ground state is to 'jump' back down, emitting a photon of light. There is always some energy lost to heat in the process, so the emitted photon has less energy than the original photon. The energy of a photon is related to its wavelength, which we perceive as color – higher energy corresponds to shorter wavelengths, lower energy to longer wavelengths. This shift in color was noted by the brilliant, if slightly off-beat, Sir George Stokes, who first described fluorescence in 1852.

See this informative web site for further information.

Emission spectrum. The emission spectrum is a measurement of the emitted energy as a function of wavelength. It is generally presented as a graph (see Figure 1). The spectrum will have a maximum but may also have secondary peaks, called 'shoulders'. In text the spectrum is often described by the wavelength of the emission peak. Some emission spectra cover a broad range of wavelengths, while others are quite sharp. This is described by the Full Width at Half Maximum (FWHM), the spectral width in nanometers at the level that is 50% of the value at the peak. The emission spectrum can be measured with a basic spectrometer like the units from Ocean Optics.

Excitation spectrum. The excitation spectrum is a measurement of the relative ability of different wavelengths of light to stimulate (excite) the fluorescence (see Figure 1). Like the emission spectrum, the excitation spectrum will have a maximum but may also have secondary peaks. The excitation spectrum tells you what wavelengths of light will be good at making that particular substance fluoresce. Unlike the emission spectrum, the excitation spectrum is difficult to measure without specialized, expensive instrumentation. To make the measurement you have to vary the wavelength of the incident light in very fine increments and measure the fluorescence response at each one.

Fluorescence lifetime. Fluorescence is short lived – once the excitation wavelengths are absent, fluorescence decays in a fraction of a second (billionths of a second), and the phenomenon ends.

Stokes shift. The Stokes shift describes the difference (in nanometers - nm) between the maximum excitation and maximum emission wavelengths. Stokes shifts of coral pigments can range from just a few nanometers to ~180nm and perhaps more.

Quantum Yield. The ratio of photons emitted through fluorescence to photons absorbed by a pigment is called the Fluorescence Quantum Yield. The higher the fluorescent quantum yield, the more efficient a pigment is at fluorescing absorbed light. Quantum yields and relative brightness vary significantly among reports, and could be due to many factors including protein purity and concentration, maturation conditions, protein source and so on (Terskikh et al., 2002).

Relative Brightness. Relative brightness is the comparison of emitted fluorescence to that of a standard (such as the fluorescent pigment from the jellyfish Aequorea, or a fluorescent dye). If the pigment’s ‘glow’ is less intense than that of the reference, the relative brightness is less <1. It is possible for the relative brightness to exceed that of the standard in which case, of course, the relative brightness will exceed 1.

Fluorescence Coupling and Förster Resonance Energy Transfer (FRET). Fluorescence Coupling occurs when a pigment’s emission overlaps the excitation spectrum of another pigment and energy is transferred between them via a radiative mechanism (that is, a photon is emitted from one pigment and absorbed by the other – this is a very low probability event). In this manner, it is possible that sequential transformation of wavelengths could occur. Coupling is possible between coral fluorescent pigments (FPs). Förster Resonance Energy Transfer (FRET, sometimes called Fluorescent Resonance Energy Transfer) is a non-radiative, ‘vibrational’ energy transfer between intimate donor and acceptor pigments. FRET is maximal when the distance between pigment granules in corals is <10µm (Salih et al., 2000). When it does occur in nature, energy transfer by FRET can be very efficient.

Photoconversion. Photoconversion is a change in absorption and emission properties of a fluorescent protein caused by incident light energy. Ultraviolet, violet, blue and green bandwidths are known to cause photoconversions. At least two sorts of photoconversion are known to occur in anthozoan pigments. These are known as ‘reddening’ and ‘photobleaching.’ Generally ‘reddening’ describes a process by which green fluorescent compounds are converted to those exhibiting red fluorescence. Photobleaching usually describes a change from green fluorescence to no fluorescence at all. Photoconversion is not responsible for all ‘reddening’. Some color shifts are due to:

Chemical oxidation. Oxygen plays a role in the maturation (colorless to green color shift) in the green fluorescent protein (GFP) of Aequorea victoria. It also plays an essential part in ‘reddening’ of fluorescent proteins in the false coral Discosoma, and ‘greening’ of a purple-red chromoprotein found in Goniopora tenuidens. We’ll discuss photoconversion in much more detail later in this series.

Photoactivatable Fluorescent Proteins (PAFPs). Some proteins of interest to aquarists can convert from a non-fluorescent state to one of fluorescence given the proper environmental triggers. Visible light (of various wavelengths and intensities) are required for photoactivation of these ‘chameleons’. Ultraviolet radiation can also activate certain pigments (more on this subject later in this series – don’t pull those UV shields yet!).

Pigment Characterization

Researchers have variously reported fluorescent proteins by color groupings (cyan-green-yellow-red), clade, numerical emission wavelength, or as overt and covert fluorescence. Fluorescence can play a major role in the appearance of an organism (such as a coral illuminated by a black light or spectrum weighted in the appropriate excitation wavelengths as found in ‘actinic’ fluorescent lamps or high-Kelvin metal halide lamps). Fluorescence can also play a part in the perceived color of a coral in daylight – strong fluorescence can ‘mix’ with the light reflected from a coral (This mixing of fluorescence and reflected light will be examined in a separate article). Not all coral pigments are fluorescent. These definitions will be used in this series of articles:

Chromoproteins. For our purposes, chromoproteins will describe the set of anthozoan pigments that do not visibly fluoresce (if at all). This includes the non-fluorescent pink and blue coral pigments (collectively called ‘pocilloporans’, Dove et al., 1995) and purple/red pigments found in some corals and anemones. ‘CP’ is the abbreviation for chromoprotein.

Fluorescent proteins can be subdivided into two categories:

Photopigments are organic compounds that harvest light energy for use in photosynthesis. Also called ‘accessory’ or ‘antennae’ pigments, the fluorescent substances of most interest to us in the discussion of coral fluorescence include chlorophyll a and phycoerythrin.

Green Fluorescent Proteins and homologues. Green fluorescent proteins (GFPs) and GFP-like proteins are those fluorescent pigments not intimately associated with photosynthesis (coral fluorescence is not due to the color of zooxanthellae!). Fluorescent proteins are variously colored cyan (CyFP), green (GFP), yellow (YFP) or red (RFP). These may have some role in photoprotection of the coral host and/or its symbiotic zooxanthellae. There are arguments for and against this line of reasoning. This will be discussed later in this series of articles.

‘Kindling’ Proteins (KPs) are sometimes referred to as Kindling Fluorescent Proteins (KFPs) and do not fall neatly into a fluorescent/non-fluorescent category as they can be transiently fluorescent. The transformation of a non-fluorescent protein to one capable of fluorescence is known as ‘kindling.’ Light (quality- often green wavelengths - and quantity or intensity) is often the environment trigger for kindling. See this site for an interesting tutorial:

Categorization of Coral Pigments

Various texts categorize visible radiation into divisions of perceived color and associated wavelengths. These categorizations do not always agree. I have unilaterally chosen a set of colors and associated wavelengths from one of my fossilized college text books and will list pigments accordingly (these are my articles – I can do anything I want!).

There is yet one more definition – the method of determining the shorthand for pigments. Again, there is no universal agreement. Matz et al., 1999 and Labas et al., 2002 use the genus name followed by a pigment number (I assume this is the order in which the pigments were identified, such as Zoanthus 1 or Discosoma 3). Matz et al. (1999) list two pigments from Zoanthus, and common sense dictates that we call them Zoanthus 1 and Zoanthus 2, yet Labas et al. (2002) list a pigment called Zoanthus 2 that has a different excitation and emission than either of the pigments listed in the Matz paper. There must, hopefully, be a better method. Some papers used abbreviations such as ‘mcavFP580’ (‘mcav’ means the pigment was isolated from the stony coral Montastraea cavernosa, while ‘FP’ stands for ‘fluorescent protein’ and the numbers describes the wavelength of the maximum fluorescent emission). This is perhaps unwieldy for our purposes, and I for several reasons have chosen to use the early (and shorter) abbreviations such as P-575

(‘P’ is for ‘pigment’ and ‘575’ is the wavelength of maximum fluorescence emission). There may be several coral genera containing a pigment with the same fluorescent emission, and the same pigment may exhibit small shifts in its exact peak location. The answer seems to list each pigment, by emission, and list the host animal in a separate column.

For non-fluorescent pigments (chromoproteins, or CPs) the wavelength number stands for the maximum absorption. Bear in mind that it is entirely possible for a single specimen to contain multiple pigments (whether they are fluorescent, or not). See Figures 3 and 4.

It is an important concept but most hobbyists are well aware of this fact – this phenomenon is apparent when specimens are viewed under ‘actinic’ fluorescent lamps.

Fluorescent and reflective pigments found in coral tissues are generally water-soluble. Loss of pigments in nature or in an aquarium would be expected to be quite low; however, corals contribute fluorescent compounds to the water column (Gentien, 1981). This scientist demonstrated that amounts of fluorescent compounds increased in prefiltered seawater when Acropora formosa, A. cerealis, A. hyacinthus, Stylophora pistillata, Favia favus, Favites flexuosa and Leptoria phyrgia specimens were incubated.

Koh (1997) found that the non-photosynthetic coral Tubastraea faulkneri secreted bioactive compounds to the water column, and some of these compounds could be visualized through fluorescence on developed thin-layer chromatographs. Allelopathic intra-actions and interactions of coral color morphs will be discussed briefly later in this series.

Phylogenetic Classifications

Though still in its infancy, computer software can sort (for our purposes) zooxanthellae and even pigments into ‘clades.’ At present, at least four pigment clades are known (A-D), which contain differing variations of cyan, green, yellow and red fluorescent proteins plus non-fluorescent chromoproteins. Figure 5 is one interpretation of pigments’ phylogenetic tree.

Software of this type is considered by some as subject to fault, but it is an interesting concept.

A Listing of Fluorescence Proteins

Table 1 is a compilation of over 90 fluorescent proteins found in various invertebrate species (non-fluorescent chromoproteins will be listed under separate cover). I have color-coded the appropriate fields to indicate approximate color of the wavelength listed. The column on the left lists the pigment’s name. Next is the maximum emission column followed by two additional columns listing second and third emissions (shoulders), if present. The excitation columns follow. (Note: Observed excitation and emission spectra can vary between instruments). Finally, the last two columns list the invertebrate host (in alphabetical order) and then a reference listing for those interested in further reading. I have used the genus and species identifications listed within various papers. Coral taxonomy is in a constant state of flux and I am not (nor do I have the time to be) qualified to revise identifications. This listing is as complete as I can make it with the references available to me. A fluorescent emission peaking at a certain wavelength does not necessarily mean that the animal host will appear the color that the wavelength indicates (individual coral colonies can contain ‘over 10,’ and possibly more, fluorescent pigments, Salih et al., 2004). Perceived color is a result of many factors.

Table 1. A compilation of anthozoan pigments reviewed in this series (listed by coral species).

Pigment	Emission	2	3	Excitation	2	3	Found in:	Reference
P-445	445	*	*	340	*	*	Acropora aspera	Dove et al., 2001
P-490	490	514	*	480	501	*	Acropora aspera	Papina et al., 2002
P-500	500	*	*	480	*	*	Acropora aspera	Dove et al., 2001
P-514	514	490	*	501	480	*	Acropora aspera	Papina et al., 2002
P-630	630	*	*	576	*	*	Acropora aspera	Dove et al., 2001
P-480	480	510	*	481	*	*	Acropora aspera (green band)*	Papina et al., 2002
P-476	476	510	575	500	475	*	Acropora aspera (orange band I)*	Papina et al., 2002
P-478	478	510	575	501	475	*	Acropora aspera (orange band II)*	Papina et al., 2002
P-487	487	517	*	*	*	*	Acropora cervicornis	Mazel,1995
P-518	518	*	*	*	*	*	Acropora cytheria @ Waikiki Aquarium	Hochberg et al., 2004
P-490	490	*	*	425	*	*	Acropora digitifera	Dove etal., 2001
P-495	495	*	*	*	*	*	Acropora digitifera	Gilmore et al., 2003
P-518	518	*	*	*	*	*	Acropora digitifera	Hochberg et al., 2004
P-590	590	*	*	570	*	*	Acropora digitifera	Dove et al., 2001
P-485	485	*	*	420	*	*	Acropora horrida	Dove et al., 2001
P-400	400	*	*	345	*	*	Acropora horrida	Dove et al., 2001
P-625	625	*	*	575	*	*	Acropora horrida	Dove et al., 2001
P-490	490	*	*	405	*	*	Acropora millepora	Cox and Salih, 2005
P-504	504	*	*	405	*	*	Acropora millepora	Cox and Salih, 2005
P-593	593	*	*	405**	*	*	Acropora millepora	Cox and Salih, 2005
P-409	409	*	*	*	*	*	Acropora nastua	Gilmore et al., 2003
P-482	482	515	*	451	430	*	Acropora nastua	Papina et al., 2002
P-483	483	*	*	427	451	*	Acropora nastua (green band)*	Papina et al., 2002
P-486	486	*	*	384	*	*	Acropora nobilis	Salih et al., 2000
P-484	484	515	*	450	502	*	Acropora secale	Papina et al., 2002
P-482	482	515	*	452	500	425	Acropora secale (green band)*	Papina et al., 2002
P-495	495	*	*	472	*	*	Acropora sp.	Karasawa et al., 2003
P-485	485	517	555	465	505	*	Acropora tenuis	Papina et al., 2002
P-517	517	555	485	505	465	*	Acropora tenuis	Papina et al., 2002
P-480	480	515	*	470	504	*	Acropora tenuis (green band)*	Papina et al., 2002
P-509	509	*	*	397	*	*	Aequoria victoria	Tsien, 1998
P-508-620	508-620	*	*	*	*	*	Agaricia agaricites @ 60m	Vermeij et al., 2002
P-565	565	*	*	490	*	*	Agaricia humilis	Mazel et al., 2003
P-486	486	*	*	426	*	*	Agaricia sp.	Mazel, 1997
P-497	497	527	*	*	*	*	Agaricia sp.	Mazel, 1995
P-513	513	545	490	*	*	*	Agaricia sp.	Mazel, 1995
P-515	515	*	*	*	*	*	Agaricia sp.	Mazel, 1995
P-557	557	600	545	*	*	*	Agaricia sp.	Mazel, 1995
P-542	542	*	*	*	*	*	Agaricia undata @ 40m	Vermeij et al., 2002
P-486	486	*	*	458	*	*	Anemonia majano	Matz et al., 1999
P-499	499	*	*	480	403	278	Anemonia sculata	Wiedenmann et al., 2002
P-595	595	*	*	574	*	*	Anemonia sculata	Wiedenmann et al., 2000
P-522	522	*	*	499	**	*	Anemonia sculata var. rufescens	Wiedenmann et al., 2000
CP-562	*	*	*	562	*	*	Anemonia sulcata, immature P-595	Wiedenmann et al., 2002
P-565	565	*	*	548	*	*	Cerianthus sp.	Ip et al., 2004
P-685	685	*	*	Violet/ Blue	Red	*	Chlorophyll - common to healthy hermatypic corals	Multiple references
P-484	484	*	*	456	*	*	Clavularia sp.	Matz et al., 1999
P-515	515	*	*	*	*	*	Colpophyllia natans	Fux and Mazel, unpublished
P-496	496	*	*	399	482	*	Condylactis gigantea	Labas et al., 2002
P-497	497	527	*	*	*	*	Condylactis gigantea	Mazel, 1995
P-508	508	*	*	494	*	*	Dendronephthya	Labas et al., 2002
P-575	575	*	*	557	*	*	Dendronephthya	Pakhomov et al., 2004
P-486	486	*	*	~448	*	*	Diploria labyrinthiformis	Fux and Mazel, unpublished
P-500	500	*	*	475	*	*	Discosoma sp.	Gross et al., 2000
P-583	583	*	*	558	530	487	Discosoma sp.	Matz et al., 1999; Baird et al., 2000
P-593	593	*	*	558	*	*	Discosoma sp. 2	Fradkov et al., 2000
P-512	512	*	*	503	*	*	Discosoma sp. 3	Labas et al., 2002
P-593	593	*	*	573	*	*	Discosoma sp. 3	Labas et al., 2002
P-483	483	*	*	443	*	*	Discosoma striata	Matz et al., 1999
P-611	611	*	*	559	*	*	Entacmaea quadricolor	Wiedenmann et al., 2002
P-487	487	517	*	*	*	*	Eusmilia fastigata	Mazel, 1995
P-518	518	*	*	503	*	*	Family Pectiniidae	Ando et al., 2004
P-517	517	*	*	507	*	*	Favia favus	Tsutsui et al., 2005
P-593	593	*	*	583	*	*	Favia favus	Tsutsui et al., 2005
P-507	507	536	575	*	*	*	Favia fragum	Mazel, 1995
P-561	561	*	*	548	*	*	Fungia concinna	Karasawa et al., 2004
P-505	505	*	*	492	*	*	Galaxea fascicularis	Karasawa et al., 2003
P-480	480	*	*	*	*	*	Goniopora tenuidens	Salih et al., 2004
P-494	494	*	*	*	*	*	Goniopora tenuidens	Salih et al., 2004
P-509	509	*	*	*	*	*	Goniopora tenuidens	Salih et al., 2004
P-520	520	*	*	488	*	*	Goniopora tenuidens	Salih et al., 1999
P-582	582	*	*	*	*	*	Goniopora tenuidens	Salih et al., 2004
P-500	500	*	*	405	481	*	Heteractis crispia	Labas et al., 2002
P-510	510	*	*	490	420	*	Heteractis magnifica	Tu et al., 2003
P-446(?)	446	*	*	380	*	*	Leptoseris fragilis	Schlichter et al., 1985
P-516	516	*	*	*	*	*	Lobophyllia hemprichii	Nienhaus et al., 2005
P-483	483	*	*	572	454	510	Lobophyllia hemprichii (red)	Salih et al., 2004
P-515	515	*	*	*	*	*	Lobophyllia hemprichii (red)	Salih et al., 2004
P-519	519	*	*	*	*	*	Lobophyllia hemprichii (red)	Salih et al., 2004
P-580	580	*	*	*	*	*	Lobophyllia hemprichii (red)	Salih et al., 2004
P-581	581	*	*	*	*	*	Lobophyllia hemprichii (red)	Salih et al., 2004
P-519-557	519-557	590	*	*	*	*	Madracis carmabi	Vermeij et al., 2002
P-520-555	520-555	590	*	*	*	*	Madracis carmabi	Vermeij et al., 2002
P-522-623	522-623	*	*	*	*	*	Madracis formosa @ 40m	Vermeij et al., 2002
P-534	534	575	*	*	*	*	Madracis formosa @ 60m	Vermeij et al., 2002
P-532	532	590	*	*	*	*	Madracis pharensis (brown tissue @ 10m)	Vermeij et al., 2002
P-533	533	590	*	*	*	*	Madracis pharensis (brown tissue @ 20m)	Vermeij et al., 2002
P-535	535	587	*	*	*	*	Madracis pharensis (brown tissue @ 60m)	Vermeij et al., 2002
P-520-570	520-570	590	*	*	*	*	Madracis pharensis (green tissue @ 10m)	Vermeij et al., 2002
P-520-570	520-570	590	*	*	*	*	Madracis pharensis (green tissue @ 20m)	Vermeij et al., 2002
P-520-570	520-570	590-620	*	*	*	*	Madracis pharensis (green tissue @ 40m)	Vermeij et al., 2002
P-520-570	520-570	590	*	*	*	*	Madracis pharensis (green tissue @ 60m)	Vermeij et al., 2002
P-519-570	519-570	590-615	*	*	*	*	Madracis pharensis (green tissue)	Vermeij et al., 2002
P-537	537	590	*	*	*	*	Madracis pharensis (grey and blue tissue @ 10m)	Vermeij et al., 2002
P-532	532	*	*	*	*	*	Madracis pharensis (red tissue @ 10m)	Vermeij et al., 2002
P-587	587	609	*	*	*	*	Madracis pharensis @  40m (brown tissue)	Vermeij et al., 2002
P-560	560	590	*	*	*	*	Madracis pharensis @ 10m (grey tentacles)	Vermeij et al., 2002
P-519-559	519-559	590	*	*	*	*	Madracis senaria	Vermeij et al., 2002
P-520-558	520-558	590	*	*	*	*	Madracis senaria	Vermeij et al., 2002
P-561	561	587-616	*	*	*	*	Madracis senaria @ 40m	Vermeij et al., 2002
P-559	559	590	*	*	*	*	Madracis senaria @ 60m	Vermeij et al., 2002
P-487	487	515	575	*	*	*	Manicina areolata	Mazel, 1995
P-487	487	515	*	*	*	*	Meandrina meandrites	Mazel,1995
P-480	480	*	*	*	*	*	Montastraea annularis	Manica and Carter, 2000
P-484	484	499	*	*	*	*	Montastraea annularis	Mazel, 1995
P-486	486	*	*	*	*	*	Montastraea annularis	Mazel, 1997
P-503	503	479	578	*	*	*	Montastraea annularis	Mazel, 1995
P-510	510	479	*	*	*	*	Montastraea annularis	Mazel, 1995
P-515	515	*	*	505	*	*	Montastraea annularis	Mazel, 1997; Manica & Carter, 2000
P-517	517	551	483	*	*	*	Montastraea annularis	Mazel, 1995
P-486	486	*	*	440	*	*	Montastraea cavernosa	Lesser et al., 2000
P-505	505	*	*	*	*	*	Montastraea cavernosa	Kelmanson & Matz, 2003
P-510	510	*	*	440	*	*	Montastraea cavernosa	Mazel et al., 2003
P-510-520	510-520	*	*	440	*	*	Montastraea cavernosa	Lesser et al., 2000
P-514	514	*	*	*	*	*	Montastraea cavernosa	Kelmanson & Matz, 2003
P-518	518	*	*	*	*	*	Montastraea cavernosa	Kelmanson & Matz, 2003
P-519	519	*	*	~505	*	*	Montastraea cavernosa	Kelmanson & Matz, 2003
P-522	522	*	*	*	*	*	Montastraea cavernosa	Kelmanson & Matz, 2003
P-575	575	~630	*	~525	~570	*	Montastraea cavernosa	Mazel, 1997
P-516	516	*	*	506	~480	*	Montastraea cavernosa (=mc2/3/4 - see P-515)	Labas et al., 2002
P-582	582	630	*	508	572	*	Montastraea cavernosa (mc1)	Kelmanson & Matz, 2003
P-515	515±3	*	*	505±3	*	*	Montastraea cavernosa (mc2/3/4)	Kelmanson & Matz, 2003
P-495	495	*	*	435	*	*	Montastraea cavernosa (mc5)	Kelmanson & Matz, 2003
P-507	507	*	*	495	*	*	Montastraea cavernosa (mc6)	Kelmanson and Matz, 2003
P-580	580	520	*	508	572	*	Montastraea cavernosa (mcavRFP)	Labas et al., 2002
P-510-623	510-623	*	*	*	*	*	Montastraea cavernosa @ 40m	Vermeij et al., 2002
P-534	534	593	*	*	*	*	Montastraea cavernosa @ 60m	Vermeij et al., 2002
P-486	486	*	*	440	*	*	Montastraea faveolata	Lesser et al., 2000
P-510-520	510-520	*	*	440	*	*	Montastraea faveolata	Lesser et al., 2000
P-575	575	*	*	506	555	*	Montipora (digitata/angulata)	Mazel, unpublished
P-485	485	*	*	420	460	465	Montipora caliculata	Dove et al., 2001
P-490	490	*	*	420-450	*	*	Montipora monasteriata	Dove et al., 2001
P-610	610	*	*	570	*	*	Montipora monasteriata	Dove et al., 2001
P-620	620	*	*	440	*	*	Montipora sp.	Kogure et al., 2006
P-515	515	*	*	*	*	*	Mycetophyllia lamarckiana	Mazel, 1997
P-515	515	*	*	~494	*	*	Mycetophyllia sp.	Fux and Mazel, unpublished
P-575	575	*	*	~569	~540	~500	Phycoerythrin within symbiotic cyanobacteria in coral	Mazel et al., 2004
P-462(?)	462	*	*	*	*	*	Platygyra daedalea	Salih et al., 2000
P-505	505	*	*	492	*	*	Plesiastrea verispora	Dove et al., 2001
P-574	574	550	*	*	*	*	Plesiastrea verispora	Dove et al., 2001
P-472	472	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-473	473	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-479	479	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-485	485	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-488	488	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-489	489	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-495	495	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-497	497	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-501	501	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-512	512	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-540	540	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-580	580	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-620	620	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-477	477	*	*	*	*	*	Plesiastrea verispora (blue)	Salih et al., 2004
P-482	482	*	*	*	*	*	Plesiastrea verispora (blue)	Gilmore et al., 2003
P-492	492	*	*	*	*	*	Plesiastrea verispora (blue)	Salih et al., 2004
P-473	473	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-479	479	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-485	485	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-489	489	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-495	495	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-497	497	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-503	503	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-508	508	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-511	511	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-512	512	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-515	515	*	*	*	*	*	Plesiastrea verispora (green morph)	Gilmore et al., 2003
P-515	515	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-518	518	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-540	540	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-580	580	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-620	620	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-440	440	*	*	358	*	*	Pocillopora damicornis	Dove et al., 2001
P-499	499	*	*	484	*	*	Pocillopora damicornis	Dove et al., 2001
P-508	508	*	*	440	450	*	Pocillopora damicornis	Apprill, 2003
P-516	516	*	*	486	*	*	Pocillopora damicornis	Salih et al., 2000
P-625	625	*	*	570	*	*	Pocillopora damicornis	Dove et al., 2001
P-530	530	*	*	450	**	*	Porites astreoides	Mazel, 2003
P-620	620	*	*	490	*	*	Porites astreoides	Mazel et al., 2003
P-496	496	*	*	*	*	*	Porites cylindrica	Salih et al., 2000
P-508	508	*	*	*	*	*	Porites cylindrica	Salih et al., 2000
P-485	485	*	*	420	*	*	Porites murrayensis	Dove et al., 2001
P-550	550	*	*	530	*	*	Porites murrayensis	Dove et al., 2001
P-625	625	*	*	570	*	*	Porites murrayensis	Dove et al., 2001
P-508	508	*	*	500	*	*	Ptilosarcus sp.	Labas et al., 2002
P-510	510	*	*	498	*	*	Renilla muelleri (sea pansy)	Labas et al., 2002
P-510	510	*	*	*	*	*	Ricordea florida	Mazel, 1995
P-513	513	*	*	*	*	*	Ricordea florida	Mazel, 1995
P-517	517	574	*	506	566	*	Ricordea florida	Labas et al., 2002
P-517	517	*	*	506	*	*	Ricordea florida	Mazel, 1995
P-518	518	*	*	508	475	*	Ricordea florida	Labas et al., 2002
P-518	518	*	*	*	*	*	Ricordea florida	Mazel, 1995
P-520	520	*	*	*	*	*	Ricordea florida	Mazel, 1995
P-573	573	510	*	*	*	*	Ricordea florida	Mazel, 1995
P-574	574	517	*	506	566	*	Ricordea florida	Labas et al., 2002
P-587-590	587-590	*	*	*	*	*	Ricordea florida (mouth)	Mazel, 1995
P-515	515	*	*	*	*	*	Ricordea sp.	Mazel, 1995
P-506	506	*	*	497	*	*	Scolymia cubensis 1	Labas et al., 2002
P-506	506	*	*	497	*	*	Scolymia cubensis 2	Labas et al., 2002
P-483	483	511	*	*	*	*	Scolymia sp.	Mazel, 1995
P-483	483	511	576	*	*	*	Scolymia sp.	Mazel, 1995
P-484	484	512	*	*	*	*	Scolymia sp.	Mazel, 1995
P-484	484	512	576	*	*	*	Scolymia sp.	Mazel, 1995
P-515	515	*	*	*	*	*	Scolymia sp.	Mazel, 1997
P-575	575	630	*	520	*	*	Scolymia sp.	Mazel et al., 2003
P-482	482	462	*	*	*	*	Seriatopora hystrix	Dove et al., 2001
P-503	503	535	*	*	*	*	Siderastrea radians	Mazel, 1995
P-503	503	535	*	*	*	*	Stoichactis sp.	Mazel, 1995
P-582	582	*	*	558	*	*	Trachyphyllia geoffroyi	Ando et al., 2002
P-576	576	*	*	*	*	*	Zoanthus - Mature form of P-522	Ianushevich et al., 2003
P-506	506	*	*	496	~440	*	Zoanthus 1	Matz et al., 1999
P-538	538	~580	*	528	494	*	Zoanthus 2	Matz et al., 1999
P-506	506	*	*	494	*	*	Zoanthus sp.	Yanushevich et al., 2002
P-538	538	*	*	525	494	*	Zoanthus sp.	Yanushevich et al., 2002
*Isolated pigments - See Comments in text.
**A good example of FRET - several pigments in A. millepora  'relay' excitation to P-593

 

Table 2. A listing of pigments (by emission spectra) of pigments discussed in Part 1 of this series.

Pigment	Emission	2	3	Excitation	2	3	Found in:	Reference
P-400	400	*	*	345	*	*	Acropora horrida	Dove et al., 2001
P-409	409	*	*	*	*	*	Acropora nastua	Gilmore et al., 2003
P-440	440	*	*	358	*	*	Pocillopora damicornis	Dove et al., 2001
P-445	445	*	*	340	*	*	Acropora aspera	Dove et al., 2001
P-446(?)	446	*	*	380	*	*	Leptoseris fragilis	Schlichter et al., 1985
P-462(?)	462	*	*	*	*	*	Platygyra daedalea	Salih et al., 2000
P-472	472	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-473	473	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-473	473	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-476	476	510	575	500	475	*	Acropora aspera (orange band I)*	Papina et al., 2002
P-477	477	*	*	*	*	*	Plesiastrea verispora (blue)	Salih et al., 2004
P-478	478	510	575	501	475	*	Acropora aspera (orange band II)*	Papina et al., 2002
P-479	479	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-479	479	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-480	480	510	*	481	*	*	Acropora aspera (green band)*	Papina et al., 2002
P-480	480	515	*	470	504	*	Acropora tenuis (green band)*	Papina et al., 2002
P-480	480	*	*	*	*	*	Goniopora tenuidens	Salih et al., 2004
P-480	480	*	*	*	*	*	Montastraea annularis	Manica and Carter, 2000
P-482	482	*	*	*	*	*	Plesiastrea verispora (blue)	Gilmore et al., 2003
P-482	482	515	*	451	430	*	Acropora nastua	Papina et al., 2002
P-482	482	462	*	*	*	*	Seriatopora hystrix	Dove et al., 2001
P-482	482	515	*	452	500	425	Acropora secale (green band)*	Papina et al., 2002
P-483	483	*	*	572	454	510	Lobophyllia hemprichii (red)	Salih et al., 2004
P-483	483	*	*	443	*	*	Discosoma striata	Matz et al., 1999
P-483	483	511	*	*	*	*	Scolymia sp.	Mazel, 1995
P-483	483	*	*	427	451	*	Acropora nastua (green band)*	Papina et al., 2002
P-483	483	511	576	*	*	*	Scolymia sp.	Mazel, 1995
P-484	484	*	*	456	*	*	Clavularia sp.	Matz et al., 1999
P-484	484	499	*	*	*	*	Montastraea annularis	Mazel, 1995
P-484	484	512	*	*	*	*	Scolymia sp.	Mazel, 1995
P-484	484	515	*	450	502	*	Acropora secale	Papina et al., 2002
P-484	484	512	576		*	*	Scolymia sp.	Mazel, 1995
P-485	485	*	*	420	*	*	Acropora horrida	Dove et al., 2001
P-485	485	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-485	485	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-485	485	*	*	420	460	465	Montipora caliculata	Dove et al., 2001
P-485	485	517	555	465	505	*	Acropora tenuis	Papina et al., 2002
P-485	485	*	*	420	*	*	Porites murrayensis	Dove et al., 2001
P-486	486	*	*	384	*	*	Acropora nobilis	Salih et al., 2000
P-486	486	*	*	458	*	*	Anemonia majano	Matz et al., 1999
P-486	486	*	*	426	*	*	Agaricia sp.	Mazel, 1997
P-486	486	*	*	~448	*	*	Diploria labyrinthiformis	Fux and Mazel, unpublished
P-486	486	*	*	*	*	*	Montastraea annularis	Mazel, 1997
P-486	486	*	*	440	*	*	Montastraea faveolata	Lesser et al., 2000
P-486	486	*	*	440	*	*	Montastraea cavernosa	Lesser et al., 2000
P-487	487	517	*	*	*	*	Acropora cervicornis	Mazel,1995
P-487	487	517	*	*	*	*	Eusmilia fastigata	Mazel, 1995
P-487	487	515	575	*	*	*	Manicina areolata	Mazel, 1995
P-487	487	515	*	*	*	*	Meandrina meandrites	Mazel,1995
P-488	488	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-489	489	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-489	489	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-490	490	*	*	425	*	*	Acropora digitifera	Dove etal., 2001
P-490	490	*	*	405	*	*	Acropora millepora	Cox and Salih, 2005
P-490	490	514	*	480	501	*	Acropora aspera	Papina et al., 2002
P-490	490	*	*	420-450	*	*	Montipora monasteriata	Dove et al., 2001
P-492	492	*	*	*	*	*	Plesiastrea verispora (blue)	Salih et al., 2004
P-494	494	*	*	*	*	*	Goniopora tenuidens	Salih et al., 2004
P-495	495	*	*	435	*	*	Montastraea cavernosa (mc5)	Kelmanson & Matz, 2003
P-495	495	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-495	495	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-495	495	*	*	*	*	*	Acropora digitifera	Gilmore et al., 2003
P-495	495	*	*	472	*	*	Acropora sp.	Karasawa et al., 2003
P-496	496	*	*	*	*	*	Porites cylindrica	Salih et al., 2000
P-496	496	*	*	399	482	*	Condylactis gigantea	Labas et al., 2002
P-497	497	527	*	*	*	*	Condylactis gigantea	Mazel, 1995
P-497	497	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-497	497	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-497	497	527	*	*	*	*	Agaricia sp.	Mazel, 1995
P-499	499	*	*	480	403	278	Anemonia sculata	Wiedenmann et al., 2002
P-499	499	*	*	484	*	*	Pocillopora damicornis	Dove et al., 2001
P-500	500	*	*	475	*	*	Discosoma sp.	Gross et al., 2000
P-500	500	*	*	405	481	*	Heteractis crispia	Labas et al., 2002
P-500	500	*	*	480	*	*	Acropora aspera	Dove et al., 2001
P-501	501	*	*	*	*	*	Plesiastrea verispora (blue morph)	Salih et al., 2004
P-503	503	479	578	*	*	*	Montastraea annularis	Mazel, 1995
P-503	503	535	*	*	*	*	Siderastrea radians	Mazel, 1995
P-503	503	535	*	*	*	*	Stoichactis sp.	Mazel, 1995
P-503	503	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-504	504	*	*	405	*	*	Acropora millepora	Cox and Salih, 2005
P-505	505	*	*	492	*	*	Plesiastrea verispora	Dove et al., 2001
P-505	505	*	*	492	*	*	Galaxea fascicularis	Karasawa et al., 2003
P-505	505	*	*	*	*	*	Montastraea cavernosa	Kelmanson & Matz, 2003
P-506	506	*	*	497	*	*	Scolymia cubensis 1	Labas et al., 2002
P-506	506	*	*	497	*	*	Scolymia cubensis 2	Labas et al., 2002
P-506	506	*	*	494	*	*	Zoanthus sp.	Yanushevich et al., 2002
P-506	506	*	*	496	~440	*	Zoanthus 1	Matz et al., 1999
P-507	507	536	575	*	*	*	Favia fragum	Mazel, 1995
P-507	507	*	*	495	*	*	Montastraea cavernosa (mc6)	Kelmanson and Matz, 2003
P-508	508	*	*	*	*	*	Plesiastrea verispora (green morph)	Salih et al., 2004
P-508	508	*	*	440	450	*	Pocillopora damicornis	Apprill, 2003
P-508	508	*	*	*	*	*	Porites cylindrica	Salih et al., 2000
P-508	508	*	*	494	*	*	Dendronephthya	Labas et al., 2002
P-508	508	*	*	500	*	*	Ptilosarcus sp.	Labas et al., 2002
P-508-620	508-620	*	*	*	*	*	Agaricia agaricites @ 60m	Vermeij et al., 2002
P-509	509	*	*	*	*	*	Goniopora tenuidens	Salih et al., 2004
P-509	509	*	*	397	*	*	Aequoria victoria	Tsien, 1998
P-510	510	479	*	*	*	*	Montastraea annularis	Mazel, 1995
P-510	510	*	*	*	*	*	Ricordea florida	Mazel, 1995
P-510	510	*	*	498	*	*	Renilla muelleri (sea pansy)	Labas et al., 2002
P-510	510	*	*	490	420	*	Heteractis magnifica	Tu et al., 2003
P-510	510	*	*	440	*	*	Montastraea cavernosa	Mazel et al., 2003
P-510-520	510-520	*	*	440	*	*	Montastraea faveolata	Lesser et al., 2000
P-510-520	510-520	*	*	440	*	*	Montastraea cavernosa	Lesser et al., 2000
P-510-623	510-623	*	*	*	*	*	Montastraea cavernosa @ 40m	Vermeij et al., 2002

Transcribing the charts from various papers has been time-consuming work. The charts and the information contained within these articles are fine for our casual purposes. In all cases, the original papers should be reviewed for exact graphical data should requirements go beyond ‘aquarium’ use.

Writing this series of articles has been tedious – sometimes frustrating. It includes information I’ve gathered over the last 20 years (see the Reference list at the end of this article). I have tried to ‘weed through’ as many references as I can, looking for those one or two pertinent sentences that are often buried in pages of important, yet irrelevant, material. More often that not, what is of extreme importance to the genetic engineer is of little practical use to us as reef hobbyists. These articles are as complete as I can make them – there is always the temptation to download just one more paper, send one more email, research one ‘last’ angle. The excitement of discovery is addictive, yet at some point I must temporarily conclude the work, knowing the paper will be dated by the time I finish typing this sentence.

This time, we’ll examine pigments with emissions up to the true green portion (P-510) of the spectrum. With that said, let’s get started!

Violet and Blue Pigments

Relatively little is known about blue fluorescent coral pigments. The biomedical field has little interest in these since they do not work well in many studies due to cellular autofluorescence. In additional, the excitation wavelengths can harm living cells. Solving the issue of blue fluorescence (or blue non-fluorescence for that matter) will probably be left in the hands of coral researchers interested in these pigments’ possible ecological functions.

It is interesting to note that excitation wavelengths for P-400, P-440 and P-445 absorb some of the ultraviolet radiation in a range that natural-occurring UV sunscreens do not- MAAs or mycosporine-like amino acids absorb UV energy up to ~360nm (Bandaranayake, 1998).

P-400

Host: Acropora horrida

• Excitation: 345nm
• Emission: 400nm
• Stokes shift: 55nm
• Reference: Dove et al., 2001
• Comments: No fluorescent quantum yield is available for this pigment. Violet fluorescence is uncommon in anthozoans. This pigment’s absorption suggests exposure to UV radiation (such as that from an unshielded metal halide lamp) would result in maximum fluorescence. Salih et al., 1998 state that certain Acropora species including, among others, A. horrida and A. tortuosa, sometimes are devoid of zooxanthellae within their polyps (the symbiotic dinoflagellates are concentrated in other tissues). In these cases, the coral polyps will not contain fluorescent pigments, but coloration is found in areas where zooxanthellae are concentrated. This certainly suggests (but does not prove) that the pigments have a biological function, perhaps as a natural sunscreen. This particular Acropora specimen appeared blue in natural light.

P-409

Host: Acropora nastua

• Excitation: Not listed
• Emission: 495nm
• Stokes shift: N/A
• Reference: Gilmore et al., 2003
• Comments: This specimen appears brown with blue tips in natural light and was collected at a depth of 1.5m at Cape Maeda, Okinawa, Japan.

P-440

Host: Pocillopora damicornis

• Excitation: 358nm
• Emission: 440nm
• Stokes shift: 82nm
• Reference: Dove et al., 2001
• Comments: This coral specimen appeared pink in natural light. Maximum absorption of coral tissue is 560nm, indicating the presence of a non-fluorescent chromoprotein (Dove et al., 1995). See Figure 7.

P-445

Host: Acropora aspera

• Excitation: 340nm
• Emission: 445nm
• Stokes shift: 105nm
• Reference: Dove et al., 2001
• Comments: Maximum absorption of coral tissue, zooxanthellae and pigments is at 580nm (data not shown) due to the presence of a non-fluorescent chromoprotein - pocilloporan. This Acropora specimen was blue in color. See Figure 8.

P-446 (?)

Although Schlichter et al. (1985, 1986) do not specifically mention the maximum fluorescence wavelength of their deep-water Leptoseris fragilis, it appears as if the fluorescent peak is close to 446nm (when variously excited by ultraviolet radiation at 380 and 390nm, violet at 400nm and blue at 430nm). The shoulder at ~380nm in Figure 10 is caused by the excitation light.

P-462 (?)

Salih et al., 2000 note a ‘dense blue’ layer of fluorescent pigment in the oral disk of a shallow-water stony coral Platygyra daedalea. No exact emission wavelength is listed, although it appears to be ~462nm in one of the article’s charts.

P-472

Host: Plesiastrea verispora

• Excitation: 330-380nm
• Emission: 472nm
• Stokes shift: Unknown
• Reference: Salih et al., 2004
• Comments: This P. verispora appeared blue in natural light, and was collected at a depth of 4-8m in Port Jackson, Australia.

P-473

Host: Plesiastrea verispora

• Excitation: 330-380nm
• Emission: 473nm
• Stokes shift: Unknown
• Reference: Salih et al., 2004
• Comments: These P. verispora appeared green or blue in natural light, and were collected at a depth of 4-8m in Port Jackson, Australia.

P-477

Host: Plesiastrea verispora

• Excitation: 330-380nm
• Emission: 476nm
• Stokes shift: Unknown
• Reference: Salih et al., 2004
• Comments: This P. verispora appeared blue in natural light, and was collected at a depth of 4-8m in Port Jackson, Australia.

P-479

Host: Plesiastrea verispora

• Excitation: 330-380nm
• Emission: 477nm
• Stokes shift: Unknown
• Reference: Salih et al., 2004
• Comments: These P. verispora appeared green or blue in natural light, and were collected at a depth of 4-8m in Port Jackson, Australia.

Green-Blue Pigments

P-480

Host: Acropora aspera

• Excitation: 504nm, with a shoulder at 510nm
• Emission: 480nm
• Stokes shift: 70-76nm
• Reference: Papina et al., 2002
• Comments: This emission was identified in a ‘green band’ from a SDS-PAGE separation.

P-482

Host: Acropora nastua

• Excitation: 451nm, shoulder at 430nm
• Emission: 482nm, with a shoulder at 515nm
• Stokes shift: 31nm
• Reference: Papina et al., 2002
• Comments: This Acropora nastua specimen was collected off the coast of Okinawa, Japan at a depth of 1.5m in August, 2001 (Papina et al., 2002). In daylight, the coral appeared brown with blue tips (the blue coloration probably due to a non-fluorescent chromoprotein). When viewed under a black light, the coral fluoresced blue. pH values ranging from 5.0 to 8.0 did not affect fluorescent quantum yield or spectral characteristics. See Figure 11.

Host: Seriatopora hystrix

• Excitation: 462nm
• Emission: 482nm
• Stokes shift: 20nm
• Reference: Dove et al., 2001
• Comments: Maximum absorption of coral tissue, zooxanthellae and pigments combined is at 560nm (data not shown). This coral appeared pink in natural light, due to a non-fluorescent pink pigment (one of a group of pigments collectively called pocilloporans, Dove et al., 1995). See Figure 12.

Host: Plesiastrea verispora

• Excitation: Not listed
• Emission: 482nm
• Stokes shift: N/A
• Reference: Gilmore et al., 2003.
• Comments: ThesePlesiastrea specimens (appearing blue in natural light) were collected in 5-9m of water at Port Jackson, Australia.

P-483

Host: Scolymia sp.

• Excitation: Not listed
• Emission: 483nm
• Stokes shift: N/A
• Reference: Mazel, 1995
• Comments: Emission shoulders at 511nm and 576nm. See Figure 13.

Host: Discosoma striata

• Excitation: ~458nm
• Emission: 483nm
• Stokes shift: 25nm
• Reference: Matz et al., 1999
• Comments: This pigment has a quantum yield of 0.46. Brightness (relative to the GFP in A. victoria) is 0.50. P-483 is structurally similar to P-583 (an orange-red pigment also found in some Discosoma specimens. Substitutions of only two amino acid residues in the DNA account for the shift of color from green-blue to orange-red). This pigment was concentrated in blue-green stripes on the animal’s oral disk. It apparently was in combination with an unidentified cyan fluorescent pigment.

Host: Acropora nastua

• Excitation: 427nm and 451nm
• Emission: 483nm
• Stokes shift: Unknown
• Reference: Papina et al., 2002
• Comments: This ‘green band’ was identified as an emission in a SDS-PAGE separation of pigments.

P-484

Host: Scolymia sp.

• Excitation: Not listed
• Emission: 484nm
• Stokes shift: N/A
• Reference: Mazel, 1995
• Comments: Shoulder emissions at 512nm and 576nm. See Figure 14.

Host: Acropora secale

• Excitation: 450nm, with an excitation shoulder at 502nm.
• Emission: 484nm, with a shoulder at 515nm.
• Stokes shift: 34nm
• Reference: Papina et al., 2002
• Comments: Collected in shallow water (1.5m depth) off the coast of Okinawa, Japan in August 2001. pH values ranging from 5.0 to 8.0 did not significantly affect fluorescent quantum yield or spectral absorption/emission qualities. Judging from the excitation and emission wavelengths, it appears from this pigment might be activated (probably by UV or violet/blue light) to P-515, which would change the apparent fluorescence from green-blue to more of a green coloration. The appearance of this coral was brown (due to zooxanthellae) with pink tips (probably due to the presence of the chromoprotein CP-560, a ‘pocilloporan’).

Host: Montastrea annularis

• Excitation: Not listed
• Emission: 484nm, with emission shoulder at 499nm.
• Stokes shift: N/A
• Reference: Mazel, 1995
• Comments:

Host: Clavularia sp

• Excitation: ~456nm
• Emission: 484nm
• Stokes shift: ~28nm
• Reference: Matz et al., 1999
• Comments: Fluorescent quantum yield is 0.48. Brightness (relative to the emission of A. victoria) is 0.77. As most hobbyists know, the intense green fluorescence is concentrated in the oral disk and tentacles.

P-485

Host: Acropora horrida

• Excitation: 420nm
• Emission: 485nm
• Stokes shift: 65nm
• Reference: Dove et al., 2001; Salih et al., 1999.
• Comments: Maximum absorption at 579nm (data not shown). Acropora horrida’s polyps often do not contain zooxanthellae – they, along with fluorescent coloration, are found elsewhere within the coral host’s tissues (Salih et al., 1999). This coral is blue in natural light.

Host: Montipora caliculata

• Excitation: 420nm, 450nm and 465nm
• Emission: 485nm
• Stokes shift: 20-65nm
• Reference: Dove et al., 2001
• Comments: Maximum absorption at 579nm (data not shown). This specimen was colored purple in natural light – probably as a result of the presence of a non-fluorescent chromoprotein.

Host: Porites murrayensis

• Excitation: 420nm
• Emission: 485nm
• Stokes shift: 65nm
• Reference: Dove et al., 2001
• Comments: This coral is purple in color in natural light, with a tissue maximum absorption at 576nm (data not shown). The purple coloration is likely due to the presence of a non-fluorescent chromoprotein.

Host: Plesiastrea verispora

• Excitation: 330-380nm
• Emission: 485nm
• Stokes shift: Unknown
• Reference: Salih et al., 2004
• Comments: These P. verispora appeared green or blue in natural light, and were collected at a depth of 4-8m in Port Jackson, Australia.

P-486

Host: Diploria labrynthiformis

• Excitation: Not listed
• Emission: 486nm
• Stokes shift: N/A
• Reference: Mazel, unpublished
• Comments: Specimen collected in the Caribbean.

Host: Agaricia sp.

• Excitation: 426nm
• Emission: 486nm
• Stokes shift: 60nm
• Reference: Mazel, 1997
• Comments: See Figure 16.