Vol. 37 No. 2, 1998
The Involvement of Calcium in Heat-induced Coral Bleaching
Shiao-Ping Huang1,3, Ku-Lin Lin1 and Lee-Shing Fang1,2,*
1Institute of Marine Resources, National Sun Yat-sen University, Kaohsiung, Taiwan 804
2National Museum of Marine Biology and Aquarium, Preparatory Office, Kaohsiung, Taiwan 800
3Department of Medical Technology, Foo-Yin Institute of Technology, Kaohsiung, Taiwan 831
Shiao-Ping Huang, Ku-Lin Lin and Lee-Shing Fang (1998) Coral
bleaching is inducible by elevated sea water temperature. At the
subcellular level the mechanism of bleaching is unclear. We
investigated the relationship between intracellular calcium
concentration and bleaching induced by elevated temperature.
Intracellular calcium concentration rose in proportion to the duration
of heat treatment. Bleaching was inhibited after applying the calcium
chelator EGTA and the cation ionophore A23187 to deplete extra- and
intracellular calcium concentrations. Further, heat-induced coral
bleaching was inhibited when the ambient calcium concentration in sea
water was reduced or depleted. The extent of bleaching was correlated
with the calcium concentration of the sea water. These findings
indicate that calcium plays a pivotal role in the subcellular mechanism
of coral bleaching.
Key words: Coral bleaching, Calcium concentration, Exocytosis.