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

Abstract

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, agebased 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.

Low and variable pH decreases recruitment efficiency in populations of a temperate coral naturally present at a CO2 vent

“…Sample size was determined based on previous studies on the species, where a similar sample size allowed to reliably characterize biometry and growth. Samples were dried, cleaned, and polyp length ( L : maximum axis of the oral disk) and dry skeletal mass ( M ) determined with standard protocols (Goffredo et al , ; Caroselli et al ).…”

“…Polyp length, width ( W : minimum axis of the oral disk), and height ( h : oral‐aboral axis) were measured with calipers (Goffredo et al , ; Caroselli et al ). Skeletal volume was estimated with the formula (Goffredo et al , , ; Caroselli et al , ). Polyps were fixed in saturated formalin solution (10% formaldehyde and 90% seawater; the solution was saturated with calcium carbonate) and transferred to the laboratories for cyto‐histometric analyses (Airi et al ; Gizzi et al ; and references therein).…”

“…where L t is individual length at age t , L ∞ is the asymptotic length (maximum expected length in the population), k is a growth constant (larger for fast growth up to the asymptotic length, smaller for slow growth), and t is the age of the individual. L ∞ and k , along with their CI, were estimated for each site through a regression analysis by least squares procedure developed in the software MATLAB R2012a (MathWorks, Natick, U.S.A.) (Caroselli et al , ).…”

“…Size at sexual maturity and percentage of mature polyps in each age class were derived from previous reproductive studies on B. europaea (Goffredo et al ; Airi et al ). The number of planulae released by each age class (biXi) was estimated by multiplying: fertility (bi), number of individuals (Xi), and percentage of mature polyps (Fi) (Goffredo et al ; Caroselli et al ).…”

“…Population demographic analyses are important to reveal relationships between organisms and their environment (Bak and Meesters ; Goffredo et al , ; Caroselli et al , ) and assess population turnover. This can be useful for restoration actions (Knittweis et al ), yet no information on ocean acidification effects on the dynamics of coral populations naturally thriving in acidified seawater is currently available.…”