Marine protozoa

Saxitoxins are water-soluble compounds that prevent proper nerve functioning. They are produced in nature by plant-like marine protozoa called dinoflagellates. Humans typically acquire such toxins by eating bivalve mollusks fed on dinoflagellates. A terrorist would likely deliver a saxitoxin as an aerosol or use it as a poison to contaminate food or water. 

Chase, Z., and N. M. Price. 1997. Metabolic and oceanographic consequences of Fe deficiency in heterotrophic marine protozoa. Limnology and Oceanography 42 1673—1684. 

Strom, S.L. (1993) Production of phaeopigments by marine protozoa results of laboratory experiments analyzed by HPLC. Deep-Sea Res. 40, 57-80. 

Johannes, R.E. (1955) Influence of marine protozoa on nutrient regeneration. Limnology and Oceanography 1 0, 434 42. 

Nagata T. and Kirchman D.L. 1990. Filtration-induced release of dissolved free amino acids application to cultures of marine protozoa. Mar. Ecol. Prog. Ser. 68 1-5. 

Increased amounts of faecal-oral water-borne pathogens (virus, bacteria and protozoa) and microbial indicators (bacterial and viral) have been reported in groundwater bodies [18], karst springs [19, 20], surface freshwater [21-26], marine waters used for bathing [27-29] and shellfish growing [30] as well as tap water [31]. 

Dive, D. Persoone, G. Protozoa as test organisms in marine ecotoxicology luxury or necessity In Ecotoxicological Testing for the Marine Environment, Persoone, G., Jaspers, E., Claus, C., Eds. State Univ. Ghent and Inst. Mar. Sci. Res. Belgium, 1984 Vol. 1, 281-306. 

Pietra, F. (1997) Secondary metaholites from marine microorganisms bacteria, protozoa, algae and fungi. Achievements and prospects. Nat. Prod. Rq>., 14,453-64. 

Bacteria, protozoa, and venomous animals synthesize numerous toxins that are used to kill their prey or to defend themselves. Sea anemones, jellyfish, cone snails, insects, spiders, scorpions, and snakes all make potent and highly specific neurotoxins. Plants form a host of alkaloids and other specialized products, some of which are specifically neurotoxic and able to deter predators. More than 500 species of marine cone snails of the genus Conus synthesize a vast array of polypeptide toxins (conotoxins), 487-489 some with unusual posttranslational modifications.490 491 The slow-moving snails are voracious predators that use their toxins, which they inject with a disposible harpoonlike tooth,492 to paralyze fish, molluscs, or worms.493... 

Ammonia is also the major nitrogenous end product in some of the simpler aquatic and marine animal forms, such as protozoa, nematodes, and even bony fishes, aquatic amphibia, and amphibian larvae. Such animals are called am-monotelic. But in many animals, NH3 is toxic, and its removal by simple diffusion is difficult. Thus, in terrestrial snails and amphibia, as well as in other animals living in environments in which water is limited, urea is the principal end product (fig. 22.6). Urea formation also helps to maintain osmotic balance with seawater in cartilagenous fishes. In such animals, most of the urea secreted by the kidney glomerulus is reabsorbed by the tubules. Indeed, the amount of nitrogen excreted by the kidneys of fishes is small com-... 

Antia, N. J. (1980). Nutritional physiology and biochemistry of marine cryptomonads and chrysomo-nads. In Biochemistry and Physiology of Protozoa (Levandowsky, M., and Humer, S. eds.). Academic Press, New York. pp. 67—115. 

Caron, D. A. (1991). Evolving role of protozoa in aquatic nutrient cycles. In Protozoa and their Role in Marine Processes (Reid, P. C., Turley, C. M., and Burkfll, P. H., eds.) Springer, Berlin, pp. 387-415. 

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