Symbiotic algae

Some of these species can carry out photosynthesis, but they may do so by engulfing symbiotic algae. It has been suggested that Grypania found in iron sediments could be the earliest eukaryotes. 

Although perhaps not an attraction to nutrients in a strict sense, symbiotic dino-flagellates (zooxanthellae) have been known for some time to be attracted to host invertebrates (which ultimately provide them with nutrients), presumably via chemical cues from the hosts (Kinzie 1974 Fitt 1984). These cues may include ammonia and nitrate released from the host (Fitt 1984). Recently Pasternak et al. (2004) demonstrated chemoattraction by Symbiodinium sp. to cell-free homogenates of juvenile soft coral polyps, which did not previously have symbiotic zooxanthellae, but not to adult polyps, which did already have symbiotic algae. The attraction was subsequently shown to be a true chemotactic response with an additional chemoki-netic effect of the algae swimming slower in the presence of host chemical cues (Pasternak et al. 2006). 

Buchsbaum Pearse, V., and Muscatine, L. Role of symbiotic algae (Zooxanthellae) in coral calcification. Biol. Bull. 141, 350-363 (1971). 

Other potential producers such as symbiotic algae, which are able to synthesize secondary products similar to palytoxin (Nakamura et al. 1993) and which live in large masses in the mesogloea of the Zoantharia, have also been considered. In this context, Maeda et al. (1985 cited from Halstead 2002) reported the detection of palytoxin or a closely related compound in the red alga Chondria crispus. However, the lack of correlation between algae (as expressed by chlorophyll a content) and... 

Recycling of nutrients between coral hosts and symbiotic dinoflageUates (zoox-antheUae) is a key reef process (see Section II above). ZooxantheUae take up the ammonium excreted by the coral animal, therefore this waste N is not released to the wider system (Muscatine and D Elia, 1978 Wilkerson and Trench, 1986). Recycling of N by the coral host could satisfy aU the nitrogen needs of the symbiotic algae (Crossland and Barnes, 1974, 1977). 

Muscatine, L. (1990). The role of symbiotic algae in carbon and energy flrtx in reef corals. In Coral Reefs . (Dubinsky, Z., ed.). Elsevier, Amsterdam, pp. 75—87. 

Wang, J. T., and Douglas, A. E. (1997). Nutrients, signals, and photosynthate release by symbiotic algae. The impact of taurine on the dinoflageUate alga Symbiodinium from the sea anemone Aiptasia pulcheUa. Plant Physiol. 114, 631—636. 

Vandermeulen, J.H. and Muscatine, L., 1974. Influence of symbiotic algae on calcification in reef corals Critique and progress report. In W.B. Vernberg (Editor), Symbiosis in the Sea. University of South Carolina Press, Columbia, pp. 1—19. 

ESCAP (1995), chemical pollution and increased sedimentation have been observed to cause bleaching in coral s symbiotic algae, which gives coral its color, causing it to abandon the coral due to environmental stress. Without these algae, the coral will eventually die. It is also expected that should sea temperature rise due to global warming, this will also exacerbate this condition. 

FIGURE 34.1 Structure of symbioimine. Symbioimine, an amphoteric iminium compound, was isolated from symbiotic algae of the marine acoel flatworm Amphiscolops sp. which was collected at Sesoko Island, Okinawa, Japan. 

Dutton GJ (1980) Glucuronidation of drugs and other compounds. CRC Press, Boca Raton, Florida Dykens JA (1984) Enzymic defenses against oxygen toxicity in marine cnidarians containing endo-symbiotic algae. Mar Biol Lett 5 291-301... 

P. fiaifovmis is normally red-brown due to the presence of a symbiotic alga. Sponges of this species living in dark caves lack the alga and are white. In a further study these white sponges... 

Muscatine, L. (1967). Glycerol excretion by symbiotic algae from corals and Tridacna and its control by the host. Science 156, 516-519. 

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