Like other reef-building corals, Pavona clavus has many microscopic, photosynthetic algae, called zooxanthellae, living within the polyp tissues. The coral and the algae have a mutually beneficial relationship, where the coral provides protection for the algae, which in return provides energy and nutrients for the coral through photosynthesis (4) (6). Both Pavona clavus and its zooxanthellae are very sensitive to changes in water temperature and acidity, and any increase in the water temperature greater than one or two degrees Celsius above the normal average can stress the coral and cause ‘bleaching’, a phenomenon in which the coral expels it zooxanthellae and turns white (4) (6). Elevated sea temperatures are often associated with short-term events, such as the El Niño phenomenon, and long-term global warming trends (7).
Very little else is known about the biology of Pavona clavus. Preliminary results from a study on spawning and recruitment in this species suggest that it may reproduce seasonally, with peak spawning events restricted to around two months each year during the full moon (August and September in the eastern Pacific) (8).
Previous studies on other Pavona species suggest that corals in this genus are typically ‘broadcast’ spawners , meaning they release, buoyant, mucus-laden egg masses into the water, which may contain as many as 9,000 to 28,000 eggs per square centimetre. It is likely that Pavona clavus is able to reproduce both sexually and asexually, with most colonies of other Pavona species containing both gonochoric (colonies composed of a single sex) and hermaphroditic populations (9).
The age of first maturity in most reef building corals is typically three to eight years, with individuals often living for more than ten years in healthy reef environments (1).