Energetic Relationships and Biogeographical Differences among Fecundity, Growth and Reproduction in the Reef Coral Pocillopora Damicornis

Data on larval production versus colony growth for the pan-Pacific coral Pocillopora damicornis indicate major differences exist in allocation between geographically separated populations. At Enewetak Atoll, Marshall Islands, P. damicornis releases planula larvae throughout the year. Measured growth rates ranged from 1.5 to 3.5 cm per year, while the caloric value of planulae released ranged from 20.2% to 167.4% of colony caloric content on a yearly basis (N = 32, x = 62.4% ± 32.8 SD/yr). No significant correlation exists between percent of colony caloric content released as planulae and depth, or with colony size. Planula production represents from 1 to 10 times the caloric value of new colony tissue growth at Enewetak. In the eastern Pacific (Panama), Pocillopora damicornis colonies did not release planulae over the 2-year period sampled, but exhibited a higher linear growth rate of 3.6 to 6 cm per year. P. damicornis colonies (ca. 10 cm in diameter) from both Enewetak and the eastern Pacific allocate similar amounts of colony caloric content to biomass production annually (80% to 100%). At Enewetak, the majority of this energy is represented by planulation, while in the eastern Pacific, the energy is allocated to colony growth and subsequent fragmentation.