Abstract
As coral reefs decline, cryptic sources of resistance and resilience to stress may be increasingly important for the persistence of these communities. Among these sources, inter‐ and intraspecific diversity remain understudied on coral reefs but extensively impact a variety of traits in other ecosystems. We use a combination of field and sequencing data at two sites in Florida and two in the Dominican Republic to examine clonal diversity and genetic differentiation of high‐ and low‐density aggregations of the threatened coral Acropora cervicornisin the Caribbean. We find that high‐density aggregations called thickets are composed of up to 30 genotypes at a single site, but 47% of genotypes are also found as isolated, discrete colonies outside these aggregations. Genet–ramet ratios are comparable for thickets (0.636) and isolated colonies after rarefaction (0.569), suggesting the composition of each aggregation is not substantially different and highlighting interactions between colonies as a potential influence on structure. There are no differences in growth rate, but a significant positive correlation between genotypic diversity and coral cover, which may be due to the influence of interactions between colonies on survivorship or fragment retention during asexual reproduction. Many polymorphisms distinguish isolated colonies from thickets despite the shared genotypes found here, including putative nonsynonymous mutations that change amino acid sequence in 25 loci. These results highlight intraspecific diversity as a density‐dependent factor that may impact traits important for the structure and function of coral reefs.
Highlights
Coral reefs worldwide are threatened by a combination of local and global stressors, including anthropogenic climate change (Hoegh‐Guldberg et al, 2007)
We use field and ‐generation sequencing data from isolated and thicket communities of the threatened coral Acropora cervicor‐ nis to examine (a) the genetic composition of each reef surveyed in Florida and the Dominican Republic, (b) differences in cover, growth, and bleaching impacts related to colony density, and (c) genetic dif‐ ferences between thickets and isolated colonies that may contribute to phenotype
We examine the threatened staghorn coral Acropora cervicornis at a range of contemporary natural densities in Florida and the Dominican Republic, finding differential clonal propagation and al‐ lelic differences between thickets and isolated colonies
Summary
Coral reefs worldwide are threatened by a combination of local and global stressors, including anthropogenic climate change (Hoegh‐Guldberg et al, 2007). Intra‐ and interspecific diversity influence various ecological outcomes in other ecosystems, including the structure of associ‐ ated invertebrate communities (Johnson, Lajeunesse, & Agrawal, 2006), disease resistance (Zhu et al, 2000), nutrient cycling, stress resistance (Hughes & Stachowicz, 2004), resilience after distur‐ bance (Reusch et al, 2005), and productivity (Huang et al, 2018). These impacts may be pronounced in foundational species, which form structure that influences other species in the community (Barbour et al, 2009). We use field and ‐generation sequencing data from isolated and thicket communities of the threatened coral Acropora cervicor‐ nis to examine (a) the genetic composition of each reef surveyed in Florida and the Dominican Republic, (b) differences in cover, growth, and bleaching impacts related to colony density, and (c) genetic dif‐ ferences between thickets and isolated colonies that may contribute to phenotype
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
