Growth, population dynamics, and reproductive output model of the non-zooxanthellate temperate solitary coral Caryophyllia inornata (Scleractinia, Caryophylliidae)

Coral age can be strictly related to size, but processes like fragmentation, fusion, and partial colony mortality can decouple this relationship. When these phenomena are negligible, such as in solitary corals, age-based growth and population dynamics models can be used. In this study, the population size, structure, and growth rates of the temperate solitary coral Caryophyllia inornata were assessed at Elba Island (north-western Mediterranean Sea). Growth rate of this species decreased exponentially with age. The two growth curves estimated by field measurements and by growth band analysis provided homogeneous relationships between size and age. The decreasing number of individuals with age indicated a steady state population, with a turnover time of 4 yr and a maximum life span of 22 yr. Maximum biomass yield and most reproductive output was by individuals of 8–15 yr age classes. The life strategy was characterized by high fecundity, continuous embryo production, high larval output, and high larval mortality.