Coralmania by Eric Borneman

Dinoflagellates - Predators, Pathogens, and Partners


Dinoflagellates are single celled protists that are superficially well-known by aquarists and laypersons alike. First discovered by Müller in 1773, and later described by Ehrenberg in the 1830's from examinations of Cretaceous cherts, the dinoflagellates are thought to have originated in the Ediacaran Era or earlier, 570 million to one billion years ago and near the base of eukaryotic evolution. These ancient organisms are directly or indirectly responsible for great benefit and harm to humankind. Does this statement sound grandiose? If so, consider that without dinoflagellates, some 7% of the world's people would lack food, some countries would fail to exist and many thousands of people, now deceased, would still be alive. These tiny cells also provide billions of dollars in economic value. In this article, I will explain how such seemingly outlandish claims are, in fact, true.

Dinoflagellates, composed of some 1,200 to 2,000 species in 130 or more genera, are classified in the Phylum Dinoflagellata and the division Pyrrophyta. Their name comes from the Greek word dinos, meaning "whirling," with the latter part of their name derived from the characteristic flagella they possess. The dinoflagellates, about half of which are photosynthetic and some of which are bioluminescent, are important components of oceanic primary productivity. They are found dispersed in all oceans and all ocean zones, and can exist in pelagic or benthic zones or within host tissues. A small percentage of them are freshwater species. They are perhaps well-known as parasites or pathogens, and some are even symbionts of invertebrate hosts. Dinoflagellates may be capable of moving and swimming (all live in aquatic environments) using two flagella. These flagella, one oriented around the cell (the transverse flagellum), and the other oriented toward the posterior (the longitudinal flagellum) are the diagnostic criteria of this group.

Dinoflagellates typically have an outer covering called the theca, or amphiesma, from which descriptive features can be ascertained. Two broad groups of dinoflagellates can be distinguished by the presence or absence of well-developed cellulose-containing thecal plates, and these groups are termed armored dinoflagellates or unarmored (naked) dinoflagellates, respectively. The theca may be divided into two parts by a transverse groove called the girdle, or cingulum, that rings the cell. The part of the theca above the girdle is the epitheca, and the part below is the hypotheca. The girdle is the location of the transverse flagellum. Another groove, the sulcus, runs longitudinally and is the location for attachment of the longitudinal flagellum. The cell's anterior end, the apex, may have an apical pore complex in armored dinoflagellates, the function of which is unknown. The posterior end of the cell, the antapex, often has projecting spines or protuberances. The theca can be shed, regenerated, or remain undeveloped during a dinoflagellate's various life stages.

Remarkable features of dinoflagellates seem to be the rule rather than the exception. Dinoflagellates may possess ejectile organelles similar to the cnidarian nematocysts. Many have numerous structures near the periphery of their cell interior called trichocysts, features similar to those found in ciliates. They are discharged by rapid hydration and are thought to function in protection, toxin discharge, secretion or prey capture. Another feature found in some species are mucocysts, located directly below the cell membrane, which eject mucilagenous material that may aid cells in adhering to substrates, or may function in prey capture. A third type of ejectile organelle is found in some species. These are the cnidocysts, and are very similar in structure to cnidarian nematocysts. They are less numerous than trichocysts and their function is unknown, but they are believed to be involved in defense or prey capture. Other unusual cellular inclusions in dinoflagellates may include a peduncle, pusule, eyespots, virus-like particles, paranuclear bodies and others, and are reviewed by Spector (1994).

Still other unusual features exist in dinoflagellates. In almost every species, nuclear chromosomes are permanently condensed in a condition that is similar to what is normally seen prior to mitosis in cell nuclei in other eukaryotes. Furthermore, dinoflagellate nuclei contain many times the amount of DNA found in most other eukaryotic cells, a feature which is discussed in more depth below. At least some species are probably polyploid. Dinoflagellates can reproduce asexually or sexually. In the former case, the cell divides longitudinally by fission, maintaining a haploid state. Each haploid daughter can, however, act as a gamete. The flagellated haploid cells can laterally fuse and form a diploid zygote that can remain motile. Under unfavorable conditions, however, some dinoflagellate zygotes enlarge and thicken (the hypnozygote stage), lose motility and produce red bodies within the cell. This diploid form, called a cyst (or dinocyst), settles to the bottom of the water column and is a "resting stage" in the dinoflagellate's life cycle. The cyst can have a tough coating of a substance called sporopollenin, or it may be embedded with calcium carbonate or silica. The cysts emerge, or germinate, in a motile stage upon encountering favorable environmental conditions, with another round of division, this time by meiosis, again resulting in a haploid cell. This type of life cycle strategy is termed haplontic.

Some interactive and basic descriptions of mitosis and meiosis can be found here: http://www.biologyinmotion.com/cell_division/
http://www.pbs.org/wgbh/nova/miracle/divide.html#

For more detailed information, visit:
http://www.biologie.uni-hamburg.de/b-online/e09/09b.htm

Trophic Strategies

Many dinoflagellates are photosynthetic and are among the major primary producers of the phytoplankton along with diatoms. This form of energy acquisition allows some 50% of dinoflagellates to be considered autotrophic, although all but a few species are auxotrophic for vitamin B12, thiamin and biotin (reviewed in Provasoli and Carlucci, 1974). Dinoflagellates are generally described as C3 plants, although some species may resemble C4 plants under certain conditions, and dinoflagellates, in general, may show some characteristics of both types. The difference between these types is whether or not three or four carbon sugars are produced and the enzymes used to fix CO2.

Chloroplasts are membrane bound organelles found within photosynthetic organisms that are the primary sites of light harvesting and photosynthesis, and contain most of the photosynthetic pigments. The chloroplasts found in red and green algae are known to have evolved from a symbiosis between a cyanobacterium and a eukaryotic cell more than one billion years ago. The primary light absorbing pigments in most plant chloroplasts are the chlorophylls. Dinoflagellates have both chlorophyll a (chl-a) and chlorophyll c (chl-c) whereas most plants and green algae contain mostly clorophyll a and, to a lesser degree chl-b. Chlorophylls d and e also exist in algae, the former mainly in some red algae. While some other organisms besides dinoflagellates contain chl-c, this pigment suggests a larger evolutionary disparity between dinoflagellates and most other "phytoplankton." It also confers an advantage in that the photosynthetic organisms containing multiple chlorophylls are able to effectively harvest light energy from a broader range of wavelengths of light. In the case of chl-b, more common in green algae, the spectrum is shifted towards the longer wavelengths into the green spectrum. Chl-c lacks as great a peak in the red spectrum as chl-a, and it might be surmised that having chl-b would be more advantageous to dinoflagellates, since less competition for light is the primary reason to harbor various pigments. However, it is the coupling of chlorophylls with peridinin, a broad band light harvesting pigment, that gives dinoflagellates a distinct advantage over other phytoplankton. Chlorophylls are the pigments largely responsible for green coloration in plants. The primary absorption peaks are at 430nm and 663nm, and 434nm and 666nm for chl-a and chl-c, respectively, corresponding to the blue and red areas of the spectrum. Because dinoflagellate chloroplasts are unusually contained by three membranes, as opposed to a normal one or two, it is believed that they likely have evolved a tertiary endosymbiosis with a plasmid that contains the additional photosynthetic pigment complex of peridinin (Morden and Sherwood 2002). The orange-red peridinin pigment absorbs very broadly, with a maximum at around 480nm and another small shoulder at 520nm. The combined units of carotenoid-chlorophyll-protein complexes (PCP complex) consisting mainly of peridinin, chlorophyll a, and one of 12 to 20 proteins, form multiple complexes where, interestingly, the interaction of chlorophyll with the peridinin protein shifts the absorption peaks of chl-a upwards about 10nm.

Some web images of action spectra for photosynthetic pigments can be found here:
http://www.prozyme.com/technical/spectra/img/percp-abs.gif
http://www.chm.bris.ac.uk/motm/chlorophyll/chloroabs.gif
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/pigment.gif
http://www.biology.mcgill.ca/undergrad/c441b/lect07/absorb.gif

An in-depth article about the interactions of peridinin with chlorophyll can be found here: http://www.nat.vu.nl/bio/pdf/D03-1C6.pdf

Here is an image of some Noctiluca, probably N. miliaris. These are purportedly the largest dinoflagellates. They lack chlorophyll, and eat smaller protozoans. They are also brilliantly bioluminescent, a fact alluded to by their name as "noctiluca" means "night light." They are shaped rather like a lily pad, and what appear to be "threads" in this image are the large flagella that are used in prey capture. Photo and caption by Ronald Shimek.

Other pigments are used indirectly as accessory pigments. Some have oxidative abilities and are used in the electron transport chains that are part of both the light and dark reactions of photosynthesis. Some even have duplicate functions, adding other levels of function to the photosynthetic cell. For example, fucoxanthin can be present as an accessory pigment in peridinin-containing species, while in some others, it may replace peridinin. Fucoxanthin is a common carotenoid primarily in diatoms and dinoflagellates.

Carotenoids are accessory pigments that are responsible for predominantly yellow and orange coloration and absorb primarily between 450nm and 550nm. Their color is usually masked by the presence of chlorophyll, but in dinoflagellates chlorophylls play second fiddle to peridinin. Carotenoids are composed of carotenes and carotenols (xanthophylls). Carotenes have numerous secondary functions, but may be most important to zooxanthellae by acting as antioxidants. Xanthophylls consist of oxygenated carotenes such as neoxanthin, violaxanthin and lutein, all of which provide characteristic coloration through absorption, either functionally or incidentally. Fucoxanthin is a yellow-green pigment with primary absorption around 530 nm that is characteristic of dinoflagellates. Also important in dinoflagellates are the xanthophylls dinoxanthin and diadinoxanthin, which play roles in preventing photooxidative damage to the photosynthetic apparatus. Also unusual for eukaryotes is that dinoflagellates show distinct circadian rhythms, most notably by the daily migration of the chloroplasts within the cells.

Color: Name:
Absorption peak (nm):
orange beta carotene
447, 449
blue-green *chlorophyll a
662, 429
orange-yellow unknown
 
yellow *diadinoxanthin
476, 446
orange-red *peridinin (64%)
480
light green chlorophyll c1, c2, c3
461, 583, 644
pink unknown
464
yellow *dinoxanthin
470, 440
  *diatoxanthin
427, 454, 482
brick-red neo-peridinin
 
yellow-green fucoxanthin
500
  zeaxanthin
455
  P-457 (neoxanthin derivative)
457
*major components
Table 1. Pigments found to be contained within zooxanthellae of corals, comprising numerous species of dinoflagellates.

Perhaps of most interest to aquarists, unarmored marine dinoflagellates of many species are the marine symbionts known as zooxanthellae that take up residence within the gastrodermis of most hermatypic (reef building) coral polyps. However, dinoflagellates have similar symbiotic roles with other marine invertebrates including sea anemones, radiolarians, sponges, foraminiferans, turbellarians, jellyfish, clams, and other groups. Much of the golden or brown color of corals is due to the zooxanthellae, and in particular their xanthophyll content and composition. The degree to which this color contributes to the corals' overall color depends on many factors, including genetics (heritable phenotype), pigment density, algal cell density, and production of animal-associated fluorescing proteins. The algal cell and pigment density can be a function of light (high light produces lower pigment/cell density and lower light produces more darkly colored colonies from higher dinoflagellate cell density/pigment concentration), and nutrients (higher nitrogen causes higher dinoflagellate cell densities). Nonetheless, symbioses with corals have enabled coral reefs to develop, since the partnership potentially allows the calcification rate of corals to outpace natural degrading and eroding processes. By enhancing the success of corals and the growth of coral reefs, dinoflagellates are responsible for many countries' coastal buffer, the habitat that allows for productive fisheries that provide up to 7% of the world's protein intake, and are indirectly responsible for billions of dollars of tourism and recreational use revenue that centers on coral reef activities.

Click here for larger image
Small, round, naked dinoflagellates lacking flagella are endosymbionts of corals, and are seen here as a nearly complete monolayer in the gastrodermis of Acropora cervicornis (upper cell layer).
Photo by Eric Borneman.

Not all dinoflagellates are autotrophic, however, and some do not photosynthesize at all. They can also exist by several variably heterotrophic strategies including species that are phagotrophic (ingesting whole cells), saprophytic (feeding on decaying matter), parasitic (feeding directly on other organisms), and mutualistic (living in mutually beneficial symbioses). Herbivory is possible in many species, and some species have potent cellulolytic enzymes to degrade plant cell walls. Phagotrophic species may attach to the surface of their prey and then develop rhizopodia that envelop the cell. Dinoflagellate species are known to feed on eggs (particularly copepod eggs), unicellular and filamentous algae, bacteria, and other microorganisms.

Toxic Dinoflagellates

Perhaps the most infamous aspect of dinoflagellates is the ability of some species to produce toxins. Blooms of toxin-producing dinoflagellates are called "red tides" and these often-seasonal events make news. Dinoflagellates are also responsible for ciguatera and other shellfish poisonings. Harmful dinoflagellate blooms produced by between 20-70 toxic species, are very similar to blooms of non-toxic species and likely occur by competitive exclusion. However, all toxic species are photosynthetic, exist in estuarine or neritic (coastal water overlying the continental shelf) areas, and produce water- or lipid-soluble toxins.

A "red tide," more properly termed a harmful algal bloom, is somewhat of a misnomer since the water rarely turns red but more usually a tint of orange, resulting from the rapid bloom and dense populations (up to 100 million cells/l) of one or more of several species of dinoflagellates (or diatoms). They can be problematic, for some of the rapidly blooming species produce potent neurotoxins called saxitoxins (and related toxins). These toxins accumulate in suspension feeders such as edible mussels and clams, and can also accumulate or kill fish or other animals, including man, that eat these shellfish. The onset of symptoms, called paralytic shellfish poisoning, can occur almost immediately upon ingestion. If inhaled, death can occur within minutes, and while there is no antidote, the toxin is inactivated by strong bases. Ironically, saxitoxin and tetradotoxin in miniscule amounts is part of the "dangerous pleasure" of eating fugu, a sashimi of various pufferfishes. Both poisons are found and both act in a similar fashion by blocking sodium channels. While in Fukuoka last year, arguably the center of fugu-dining in Japan, I opted not to roll the dice on saxitoxin/tetratodotoxin ingestion. Other dinoflagellate species can produce brevetoxins that cause symptoms similar to those of neurotoxic shellfish poisoning. Massive fish kills along the Gulf Coast have been caused by brevetoxin-producing dinoflagellate species, and aerosolization of seaspray during red tides can cause sickness in those living on or visiting coastlines. The most common marine toxin disease is ciguatera, a neurologic gastrointestinal and cardiovascular impairment caused by the accumulation of dinoflagellate-produced ciguatoxin in contaminated fish. The higher the trophic level of the fish, the more concentrated the ciguatoxin, and barracuda, eels, groupers, snappers and jacks are notorious for causing cases of ciguatera in humans after being eaten. For more information on Ciguatera, follow this link: http://www.cdc.gov/nceh/ciguatera/default.htm

Click here for larger image
Barracuda, while tasty, are one of the fish most likely to cause ciguatera poisoning if eaten, particularly older and larger fish. Photo by Eric Borneman.

A more recent and frightening discovery in 1988 of a toxic dinoflagellate can be found in Pfiesteria piscicida. This species has been responsible for massive fish kills along the Atlantic coast of the United States and produces at least one very potent neurotoxin. The blooms, occurring mainly in estuarine habitats, are short-lived, often lasting only a few hours. What makes Pfiesteria so intriguing is that there are at least 24 forms in its life cycle, including normal non-toxic photosynthesizing forms, toxic and non-toxic cyst forms, and a predatory form. One toxin produced by a cyst stage stuns fish, facilitating attachment of the dinoflagellate. The same toxin causes tissue necrosis and open sores. Another toxin affects fish respiration. Then, the dinoflagellate adopts a micropredatory role and feeds on the dissolving tissue. For more information, visit: http://www.epa.gov...pfiesteria/fact.html.

Dinoflagellates in the Aquarium: "Snotty" Dinoflagellates and Fish Parasites

Besides the precautions that should be taken for toxic dinoflagellates which are certainly potentially present in marine aquaria, and the obvious interest in symbiotic species such as zooxanthellae, aquarists are probably well-familiar with reports or experiences of a brown, slimy, snotty algae that traps gas bubbles and covers the surfaces of live rock, tank walls, and even corals. A web photo of the appearance of this material can be found here. Such periodic blooms are often reported in the spring, and seem to correlate with deaths of fish and especially with lethargy or paralysis and death of herbivorous snails. These are covered extensively by Sprung and Delbeek (1994), along with methods of eradication. Such cases may indeed be blooms of toxic dinoflagellates. There are, however, other toxic microalgae, other slimy snotty algae, and other algae that trap gas bubbles. The gas bubbles are likely oxygen being produced by photosynthesis, and of the many mat or film-forming microorganisms, photosynthetic protists, algae, and cyanobacteria can all appear very similar. Cyanobacteria, in particular, are also well known for producing toxins.

During dives in both the Caribbean and Indo-Pacific, I have noticed snotty brown material with gas bubbles that appears to be localized areas of what are described as dinoflagellates in reef tanks. Recently, it was found that these accumulations on reefs are composed of chrysophytes, specifically Chrysocystis fragilis (Schaffelke et al. 2004). Interestingly, many chrysophytes have several life stages, can produce toxins especially during blooms (Boenikg and Stadler 2004), contain pigments similar to those in dinoflagellates, and can have two flagella. They are golden brown in color, and could be easily confused with dinoflagellates, even if examined by microscopy. They are also correlated with tissue mortality and bleaching signs where they cover living corals in the wild, similar to what is seen in aquaria. For more information on chrysophytes, visit the following page: http://www.ucmp.berkeley.edu/chromista/chrysophyta.html.

Click here for larger image
Chrysophytes on reef rock between Millepeora alcicornis and Montastraea faveolata. Photo by Eric Borneman.

The last and perhaps best-known dinoflagellate groups are parasites of fish, Amyloodinium ocellatum and Cryptocaryon irritans, better known as marine velvet and ick, respectively. These common and troublesome parasites are covered extensively in the aquarium and scientific literature. An article on them has also appeared in this magazine.

Conclusion

Dinoflagellates are an evolutionarily ancient lineage that encompasses extremely diverse and abundant single-celled organisms. Utilizing mixotrophic strategies and possessing numerous unusual and characteristic features, the dinoflagellates are well-adapted for survival. Photosynthetic species have chloroplasts and mitochondria, both believed to originally represent endosymbioses with a primitive prokaryotic cell. Dinoflagellates with a triple membrane enclosed perdinin-containing chloroplast and a tendency to form parasitic or mutualistic symbioses with other marine species probably represent a favorably adaptive lifestyle. Understanding the nature of their ecology and biology better equips aquarists to deal with both troublesome and beneficial species. If nothing else, brown corals may take on a whole new "light" in the eyes of their beholders.



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References and Additional Reading

General

Website: http://www.palaeos.com/Eukarya/Units/Alveolata/Dinoflagellata.000.html

Toxic dinoflagellates

Anderson DM, AW White and DG Baden (eds). 1985. Toxic dinoflagellates. Proceedings of the Third International Conference on Toxic Dinoflagellates. Elsevier, NY.

Boenigk J, Stadler P. 2004. Potential toxicity of chrysophytes affiliated with Poteriochromonas and related 'Spumella-like' flagellates. J Plank Res 26: 1507-1514

Carreto JI, Carigman MO, Montoya NG. 2001. Comparative studies on mycosporine-like amino acids, paralytic shellfish toxins and pigment profiles of the toxic dinoflagellates Alexandrium tamarense, A. catenella and A. minutum Mar Ecol Prg Ser 223: 49-60

Gainey, L.F. and S.E. Shumway. 1988. A compendium of the responses of bivalve molluscs to toxic dinoflagellates. J. Shellfish Research 7: 6223-628.

Hallegraeff, G.M. 1993. A review of harmful algal blooms and their apparent global increase. Phycologia 32: 79-99.

Lassus P, Arzul G, E-Le Denn E, Gentien P, Marcaillou-LeBaut C (eds). 1995. Harmful marine algal blooms. Proceedings of the Sixth International Conference on Toxic Marine Phytoplankton. Lavoisier: Paris

Smayda, T.J. and Y. Shimuzu (eds) 1993. Toxic phytoplankton blooms in the sea. Proceedings of the 5th International Conference on Toxic Marine Phytoplankton. Elsevier: Amsterdam.

Steidinger K.A., Baden D.G. 1984. Toxic marine dinoflagellates. In: Dinoflagellates (Spector D.L., ed.) Academic Press, NY: 201-261.

Taylor D. L., and H.H. Seliger (eds) 1978. Toxic dinoflagellate blooms. Proceedings of the Second International Conference on Toxic Dinoflagellate Blooms. Elsevier, NY.

Identification

Dodge J.D. 1985. Atlas of dinoflagellates: a scanning electron microscope survey. Farrand Press, London.

Dodge J.D. 1984. Dinoflagellate taxonomy. In: Dinoflagellates (Spector D.L., ed.) Academic Press, NY: 17-42.

Ecology and Evolution

Fensome RA, MacRae RA, Williams GL. Dinoflagellate evolution and diversity through time. Online http://www.mar.dfo-mpo.gc.ca/science/review/e/pdf/dinoflagellate.pdf

Gast RJ, Caron DA. 1996. Molecular phylogeny of symbiotic dinoflagellates from planktonic foraminifera and radiolaria. Mol Biol Evol 13: 1192-1197

Hackett JD, Anderson DM, Erdner DL, Bhattacharya D. 2004. Dinoflagellates: a remarkable evolutionary experiment. Am J Bot 91: 1523-1534

Loeblich A.R. 1984. Dinoflagellate evolution. In: Dinoflagellates (Spector D.L., ed.) Academic Press, NY: 481-522

Morden C.W., Sherwood A.R. 2002. Continued evolutionary surprises among dinoflagellates. Proc Natl Acad Sci, USA 99: 11558-11560

Biology

Loeblich A.R. 1984. Dinoflagellate physiology and biochemistry. In: Dinoflagellates (Spector D.L., ed.) Academic Press, NY: 299-324

Pfiester L.A. 1984. Sexual reproduction. In: Dinoflagellates (Spector D.L., ed.) Academic Press, NY: 181-199

Pfiester, L.A. 1989. Dinoflagellate sexuality. Int Rev Cytol 114: 249-272.

McLachlan, J., Chen, L. C.-M., and Edelstein, T. 1971. The culture of four species of Fucus under laboratory conditions.

Provasoli, L., and Carlucci, A.F. 1974. Vitamins and growth regulators. In: Algal Physiology and Biochemistry (Stewart, W.D.P., ed.). Blackwell Scientific, UK, pp. 741-87.

Roberts, K. R. 1991. The flagellar apparatus and cytoskeleton of dinoflagellates; organization and use in systematics. In: The biology of free-living heterotrophic flagellates (Patterson D..J. and Larsen J. (eds.). Clarendon Press, Oxford: 285-302.

Spector D.L. 1984. Dinoflagellate nuclei. In: Dinoflagellates (Spector D.L., ed.) Academic Press, NY: 107-47

Spector D.L. 1984. Unusual inclusions. In: Dinoflagellates (Spector D.L., ed.) Academic Press, NY: 365-390

Sweeney B.M. 1984. Circadian rhythmicity in dinoflagellates. In: Dinoflagellates (Spector D.L., ed.) Academic Press, NY: 343-364

Taylor, F.J.R. (ed.). 1987. The Biology of Dinoflagellates. Botanical Monographs, Volume 21. Blackwell Scientific Publications, Oxford 785 pp.

Photosynthesis and Pigments

Damjanovic A, Thorsten R, Schulten K. 2000. Excitation transfer in the peridinin-chlorophyll-protein of Amphidinium carterae. Biophys J 79: 1695-1705

Dutton HJ. 1997. Carotenoid-sensitized photosynthesis: quantum efficiency, fluorescence and energy transfer. Photosynth Res 52: 175-185

Frank HA, Chynwat V, Desamero RZB, Farhoosh R, Erickson J, Bautista J. 1997. On the photophysics and photochemical properties of carotenoids and their role as light-harvesting pigments in photosynthesis. Pure Appl Chem 69: 2117-2124

Levy O, Dubinsky Z, Achituv Y.. 2003. Photobehavior of stony corals: responses to light spectra and intensity. J Exp Biol 206: 4041-4049

Liaen-Jensen S. 1991. Marine carotenoids: recent progress. Pure Appl Chem 63: 1-12

Mamoru M, Katoh T. 1991. Carotenoids in photosynthesis: absorption, transfer and dissipation of light energy. Pure Appl Chem 63: 123-130

Maritorena S, Payri C, Babin M, Claustre H, Bonnafous L, Morel A, Rodière M. 2002. Photoacclimatization in the zooxanthellae of Pocillopora verrucosa and comparison with a pelagic algal community. Oceanologica Acta 25: 125-134.

Poryvkina L, BabichenkoS, Leeben A. 2001. Analysis of phytoplankton pigments by excitation spectra of fluorescence. Proc EARS-eL-SIG-Workshop LIDAR, Dresden/FRG, June 16-17 2000: 224-232.

Young AJ, Phillip D, Ruban AV, Horton P, Frank HA. 1997. The xanthophylls cycles and carotenoid-mediated dissipation of excess excitation energy in photosynthesis. Pure Appl Chem 69: 2125-2130

Others

Brusca RC, Brusca GJ (eds.) 2003. Invertebrates, 2nd ed. Sinauer Associates, Sunderland. 936 pp.

Schaffelke B, Heimann K, Marshall PA, Ayling AM. 2004. Blooms of Chrysocystis fragilis on the Great Barrier Reef. Coral Reefs 23: 514

Sprung J, Delbeek JC. 1994. The Reef Aquarium. Ricordea Publishing, Coconut Grove. 544pp.




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Dinoflagellates - Predators, Pathogens, and Partners by Eric Borneman - Reefkeeping.com