Search for: All records

Abstract Phenotypic variability is the ability of the same species to express different phenotypes under different environmental conditions. Several coral species that exist along a broad depth distribution have been shown to differ in skeletal morphology and nutrient acquisition at different depths, which has been attributed to variability in response to differing levels of light availability. This study examined the phenotypic variability of two common depth generalist corals,Montastraea cavernosaandPorites astreoides,along a gradient from 10 to 50 m in the Cayman Islands, by examining changes in skeletal morphology, photophysiology, symbiont cell density, and chlorophyll concentration. Skeletal features ofM. cavernosawere found to increase in size from 10 to 30 m, but returned to smaller sizes from 30 to 50 m, whileP. astreoidesskeletal features continued to increase in size from 10 to 40 m. No differences were observed in either symbiont density or chlorophyll concentration across depths for either species. However, all photophysiological parameters exhibited significant depth-dependent variations in both species, revealing adaptive strategies to different light environments. These results suggest that both species have high variability in response to depth. Patterns of skeletal morphology and photophysiology, however, suggest thatM. cavernosamay be more variable in regulating photosynthetic efficiency compared toP. astreoides, which likely facilitates the broader depth distribution of this species.