Coral metabolic activity

A coral reef may be considered as a self-supporting system, but with considerable interzonal transfer. The major site of metabolic activity is the reef flat, and probably the upper reaches of the seaward slope. The reef flat is a net consumer requiring an input of organic carbon. This gain is probably obtained from the algal pavement and the upper slope, which are seaward of the reef flat. 

Figure 1.10 Showing widespread colonization of coral skeleton by primary mesenchymal stem cells stained green to show that they are viable and metabolically active.

By interfering with any one of the many phases associated with these second messenger pathways, toxins may alter channel gating. For example, the blue green algal toxins, aplysiatoxin, and lyngbyatoxin bind to and activate protein kinase C in a manner similar to phorbol esters (73). They also stimulate arachidonic acid metabolism (74). The coral toxin, palytoxin, also stimulates arachidonic acid breakdown albeit by an unknown mechanism (74) and affects other biochemical activities of the cell (see chapters by Fujiki et al., Wattenberg et al., and Levine et al., this volume). 

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