<P> Although corals exist both in temperate and tropical waters , shallow - water reefs form only in a zone extending from approximately 30 ° N to 30 ° S of the equator . Tropical corals do not grow at depths of over 50 meters ( 160 ft ) . The optimum temperature for most coral reefs is 26 -- 27 ° C ( 79 -- 81 ° F ) , and few reefs exist in waters below 18 ° C ( 64 ° F ) . However , reefs in the Persian Gulf have adapted to temperatures of 13 ° C ( 55 ° F ) in winter and 38 ° C ( 100 ° F ) in summer . There are 37 species of scleractinian corals identified in such harsh environment around Larak Island . </P>
<P> Although corals exist both in temperate and tropical waters , shallow - water reefs form only in a zone extending from approximately 30 ° N to 30 ° S of the equator . Tropical corals do not grow at depths of over 50 meters ( 160 ft ) . The optimum temperature for most coral reefs is 26 -- 27 ° C ( 79 -- 81 ° F ) , and few reefs exist in waters below 18 ° C ( 64 ° F ) . However , reefs in the Persian Gulf have adapted to temperatures of 13 ° C ( 55 ° F ) in winter and 38 ° C ( 100 ° F ) in summer . There are 37 species of scleractinian corals identified in such harsh environment around Larak Island . </P>
the optimum temperature for coral formation occurs where the average annual temperatures are between
the optimum temperature for coral formation occurs where the average annual temperatures are between
26 -- 27 ° C ( 79 -- 81 ° F )
26 -- 27 ° C ( 79 -- 81 ° F )