scholarly journals Environmental specialization and cryptic genetic divergence in two massive coral species from the Florida Keys Reef Tract

2020 ◽  
Author(s):  
John P. Rippe ◽  
Groves Dixon ◽  
Zachary L. Fuller ◽  
Yi Liao ◽  
Mikhail Matz
Keyword(s):  
Coral Species ◽  
De Novo ◽  
Environmental Gradients ◽  
Florida Keys ◽  
Divergent Selection ◽  
Geographic Ranges ◽  
Broadcast Spawning ◽  
Reef Tract ◽  
Spatially Varying ◽  
Spatially Varying Selection

ABSTRACTBroadcast-spawning coral species have wide geographic ranges, spanning strong environmental gradients, but it is unclear how much spatially varying selection these gradients actually impose. Strong divergent selection might present a considerable barrier for demographic exchange between disparate reef habitats. We investigated whether the cross-shelf gradient (nearshore - offshore - deep) is associated with spatially varying selection in two common coral species, Montastraea cavernosa and Siderastrea siderea, in the Florida Keys. Toward this end, we generated a de novo genome assembly for M. cavernosa and used 2bRAD to genotype 20 juveniles and 20 adults of both species from each of the three reef zones to identify signatures of selection occurring within a single generation. Unexpectedly, each species was found to be composed of four genetically distinct lineages, with gene flow between them still ongoing but highly reduced in 13.0-54.7% of the genome. Each species includes two sympatric lineages that are only found in the deep (20 m) habitat, while the other lineages are found almost exclusively on the shallower reefs (3-10 m). The two “shallow” lineages of M. cavernosa are also specialized for either nearshore or offshore: comparison between adult and juvenile cohorts indicates that cross-shelf migrants are more than twice as likely to die before reaching adulthood than local recruits. Siderastrea siderea and M. cavernosa are among the most ecologically successful species on the degraded Florida Keys Reef Tract, and this work offers important insight on the genomic background of divergent selection and environmental specialization that may in part explain their resilience and broad environmental range.

scholarly journals Environmental specialization and cryptic genetic divergence in two massive coral species from the Florida Keys Reef Tract

2021 ◽  
Author(s):  
John P. Rippe ◽  
Groves Dixon ◽  
Zachary L. Fuller ◽  
Yi Liao ◽  
Mikhail Matz
Keyword(s):  
Genetic Divergence ◽  
Coral Species ◽  
Florida Keys ◽  
Massive Coral ◽  
Reef Tract

scholarly journals Genetic structure and diversity of the mustard hill coral Porites astreoides along the Florida Keys reef tract

2021 ◽  
Vol 51 (4) ◽  
Author(s):  
Dominique N. Gallery ◽  
Michelle L. Green ◽  
Ilsa B. Kuffner ◽  
Elizabeth A. Lenz ◽  
Lauren T. Toth
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Relatedness ◽  
Florida Keys ◽  
Genetic Population ◽  
High Genetic Diversity ◽  
Western Atlantic ◽  
Porites Astreoides ◽  
Single Well ◽  
Reef Tract

AbstractIncreases in local and global stressors have led to major declines in coral populations throughout the western Atlantic. While abundances of other species have declined, however, the relative abundance of the mustard hill coral, Porites astreoides, has increased. Porites astreoides is relatively resilient to some stressors, and because of its mixed reproductive strategies, its populations often recover quickly following disturbances. The ability for P. astreoides to continue as a potential “winner” in western Atlantic reefs relies on maintaining sufficient genetic variation within populations to support acclimatization and adaptation to current and future environmental change. Without high genetic diversity and gene flow within the population, it would have limited capacity for adaptation and the species’ competitive advantages could be short-lived. In this study, we determined the genetic relatedness of 37 P. astreoides colonies at four shallow reefs along the offshore Florida Keys Reef Tract (FKRT), a region particularly hard-hit by recent disturbances. Using previously designed microsatellite markers, we determined the genetic diversity and connectivity of individuals among and between sites. Our results suggest that the FKRT likely contains a single, well-mixed genetic population of P. astreoides, with high levels of gene flow and evidence for larval migration throughout the region. This suggests that regional populations of P. astreoides likely have a higher chance of maintaining resilience than many other western Atlantic species as they face current and future disturbances.

scholarly journals Genotype by environment interactions in coral bleaching

2021 ◽  
Vol 288 (1946) ◽  
pp. 20210177
Author(s):  
Crawford Drury ◽  
Diego Lirman
Keyword(s):  
Coral Bleaching ◽  
Environmental Gradients ◽  
Explanatory Power ◽  
Cell Signalling ◽  
Conservation Strategies ◽  
Acropora Cervicornis ◽  
Genotype By Environment ◽  
Significant Enrichment ◽  
Reef Tract ◽  
Reef Decline

Climate-driven reef decline has prompted the development of next-generation coral conservation strategies, many of which hinge on the movement of adaptive variation across genetic and environmental gradients. This process is limited by our understanding of how genetic and genotypic drivers of coral bleaching will manifest in different environmental conditions. We reciprocally transplanted 10 genotypes ofAcropora cervicornisacross eight sites along a 60 km span of the Florida Reef Tract and documented significant genotype × environment interactions in bleaching response during the severe 2015 bleaching event. Performance relative to site mean was significantly different between genotypes and can be mostly explained by ensemble models of correlations with genetic markers. The high explanatory power was driven by significant enrichment of loci associated DNA repair, cell signalling and apoptosis. No genotypes performed above (or below) bleaching average at all sites, so genomic predictors can provide practitioners with ‘confidence intervals' about the chance of success in novel habitats. These data have important implications for assisted gene flow and managed relocation, and their integration with traditional active restoration.

scholarly journals Testing biodiversity theory using species richness of reef-building corals across a depth gradient

2019 ◽  
Vol 15 (10) ◽  
pp. 20190493 ◽  
Author(s):  
T. Edward Roberts ◽  
Sally A. Keith ◽  
Carsten Rahbek ◽  
Tom C. L. Bridge ◽  
M. Julian Caley ◽  
...  
Keyword(s):  
Species Richness ◽  
Large Scale ◽  
Coral Species ◽  
Environmental Gradients ◽  
Abiotic Factors ◽  
Empirical Support ◽  
Null Model ◽  
Local Scale ◽  
Small Scale ◽  
Energy Availability

Natural environmental gradients encompass systematic variation in abiotic factors that can be exploited to test competing explanations of biodiversity patterns. The species–energy (SE) hypothesis attempts to explain species richness gradients as a function of energy availability. However, limited empirical support for SE is often attributed to idiosyncratic, local-scale processes distorting the underlying SE relationship. Meanwhile, studies are also often confounded by factors such as sampling biases, dispersal boundaries and unclear definitions of energy availability. Here, we used spatially structured observations of 8460 colonies of photo-symbiotic reef-building corals and a null-model to test whether energy can explain observed coral species richness over depth. Species richness was left-skewed, hump-shaped and unrelated to energy availability. While local-scale processes were evident, their influence on species richness was insufficient to reconcile observations with model predictions. Therefore, energy availability, either in isolation or in combination with local deterministic processes, was unable to explain coral species richness across depth. Our results demonstrate that local-scale processes do not necessarily explain deviations in species richness from theoretical models, and that the use of idiosyncratic small-scale factors to explain large-scale ecological patterns requires the utmost caution.

scholarly journals Evolutionary trends in onshore-offshore distribution patterns of mushroom coral species (Scleractinia: Fungiidae)

2012 ◽  
Vol 81 (4) ◽  
pp. 199-221 ◽  
Author(s):  
Bert W. Hoeksema
Keyword(s):  
Related Species ◽  
Coral Species ◽  
Environmental Gradients ◽  
Distribution Patterns ◽  
Similar Distribution ◽  
Closely Related Species ◽  
Species Association ◽  
Incidence Data ◽  
Coral Fauna ◽  
Mushroom Coral

A phylogenetically based comparative analysis of onshore-offshore distribution patterns of mushroom coral species (Scleractinia: Fungiidae) was made to reconstruct an evolutionary scenario for differentiation in fungiid shelf habitats. This phyloecological study integrates data on fungiid distribution patterns along environmental gradients on the Spermonde Shelf, SW Sulawesi, with a recently published phylogeny reconstruction of the Fungiidae. A mushroom coral fauna of 34 species was used to compare their distributions by use of 50-m2 belt quadrats in transects (1) from the mainland to the shelf edge, (2) around reefs with regard to predominant wind directions, and (3) over bathymetrical reef zones. Species association ordinations were made for each of the four shelf zones using both abundance and incidence data to examine whether closely related species cooccurred. Some closely related species or even sister species appeared to show very similar distribution patterns and to coexist in high abundances. These results indicate that there may not be community saturation and competitive exclusion among mushroom corals species, most of which are free-living. In reconstructions of fungiid habitat evolution, offshore reef slopes appear to be original (ancestral), whereas onshore habitats, shallow reef flats, and deep sandy reef bases seem to be derived. The latter is in contrast with an earlier hypothesis, in which deep sandy substrates were considered ancestral mushroom coral habitats.

scholarly journals Spatially varying selection shapes life history clines among populations of Drosophila melanogaster from sub-Saharan Africa

2015 ◽  
Vol 28 (4) ◽  
pp. 826-840 ◽  
Author(s):  
D. K. Fabian ◽  
J. B. Lack ◽  
V. Mathur ◽  
C. Schlötterer ◽  
P. S. Schmidt ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Life History ◽  
Sub Saharan Africa ◽  
Sub Saharan ◽  
Spatially Varying ◽  
Spatially Varying Selection

scholarly journals The Genetic Consequences of Spatially Varying Selection in the Panmictic American Eel (Anguilla rostrata)

Genetics ◽  
2011 ◽  
Vol 190 (2) ◽  
pp. 725-736 ◽  
Author(s):  
Pierre-Alexandre Gagnaire ◽  
Eric Normandeau ◽  
Caroline Côté ◽  
Michael Møller Hansen ◽  
Louis Bernatchez
Keyword(s):  
Anguilla Rostrata ◽  
American Eel ◽  
Spatially Varying ◽  
Spatially Varying Selection

scholarly journals Major QTL controls adaptation to serpentine soils in Mimulus guttatus

2018 ◽  
Author(s):  
Jessica P. Selby ◽  
John H. Willis
Keyword(s):  
Genetic Basis ◽  
Common Garden ◽  
Serpentine Soils ◽  
Mimulus Guttatus ◽  
Fitness Effects ◽  
Spatially Varying ◽  
Spatially Varying Selection ◽  
Physical Challenges ◽  
Two Populations ◽  
Major Qtl

ABSTRACTSpatially varying selection is a critical driver of adaptive differentiation. Yet, there are few examples where the fitness effects of naturally segregating variants that contribute to local adaptation have been measured in the field. This project investigates the genetic basis of adaption to serpentine soils in Mimulus guttatus. Reciprocal transplant studies show that serpentine and non-serpentine populations of M. guttatus are genetically differentiated in their ability to survive on serpentine soils. We mapped serpentine tolerance by performing a bulk segregant analysis on F2 survivors from a field transplant study and identify a single QTL where individuals that are homozygous for the non-serpentine allele do not survive on serpentine soils. This same QTL controls serpentine tolerance in a second, geographically distant population. A common garden study where the two serpentine populations were grown on each other′s soil finds that one of the populations has significantly lower survival on this “foreign” serpentine soil compared to its home soil. So, while these two populations share a major QTL they either differ at other loci involved in serpentine adaptation or have different causal alleles at this QTL. This raises the possibility that serpentine populations may not be broadly tolerant to serpentine soils but may instead be locally adapted to their particular patch. Nevertheless, despite the myriad chemical and physical challenges that plants face in serpentine habitats, adaptation to these soils in M. guttatus has a simple genetic basis.

scholarly journals Temperature regimes impact coral assemblages along environmental gradients on lagoonal reefs in Belize

2016 ◽  
Author(s):  
Justin H. Baumann ◽  
Joseph E. Townsend ◽  
Travis A. Courtney ◽  
Hannah E. Aichelman ◽  
Sarah W. Davies ◽  
...  
Keyword(s):  
Life History ◽  
Community Structure ◽  
Coral Reefs ◽  
Coral Species ◽  
Environmental Gradients ◽  
Coral Community ◽  
Life History Strategies ◽  
Percent Cover ◽  
Chl A ◽  
Reef System

AbstractCoral reefs are increasingly threatened by global and local anthropogenic stressors such as rising seawater temperature, nutrient enrichment, sedimentation, and overfishing. Although many studies have investigated the impacts of local and global stressors on coral reefs, we still do not fully understand how these stressors influence coral community structure, particularly across environmental gradients on a reef system. Here, we investigate coral community composition across three different temperature and productivity regimes along a nearshore-offshore gradient on lagoonal reefs of the Belize Mesoamerican Barrier Reef System (MBRS). A novel metric was developed using ultra-high-resolution satellite-derived estimates of sea surface temperatures (SST) to classify reefs as exposed to low (lowTP), moderate (modTP), or high (highTP) temperature parameters over 10 years (2003 to 2012). Coral species richness, abundance, diversity, density, and percent cover were lower at highTP sites relative to lowTP and modTP sites, but these coral community traits did not differ significantly between lowTP and modTP sites. Analysis of coral life history strategies revealed that highTP sites were dominated by hardy stress tolerant and fast-growing weedy coral species, while lowTP and modTP sites consisted of competitive, generalist, weedy, and stress-tolerant coral species. Satellite-derived estimates of Chlorophyll-a (chl-a) were obtained for 13-years (2003-2015) as a proxy for primary production. Chl-a concentrations were highest at highTP sites, medial at modTP sites, and lowest at lowTP sites. Notably, thermal parameters correlated better with coral community traits between site types than productivity, suggesting that temperature (specifically number of days above the thermal bleaching threshold) played a greater role in defining coral community structure than productivity on the MBRS. Dominance of weedy and stress-tolerant genera at highTP sites suggests that corals utilizing these two life history strategies may be better suited to cope with warmer oceans and thus may warrant protective status under climate change.

scholarly journals Demographic compensation does not rescue populations at a trailing range edge

2018 ◽  
Vol 115 (10) ◽  
pp. 2413-2418 ◽  
Author(s):  
Seema Nayan Sheth ◽  
Amy Lauren Angert
Keyword(s):  
Environmental Gradients ◽  
Demographic Data ◽  
Species Range ◽  
Severe Drought ◽  
Vital Rates ◽  
Population Declines ◽  
Geographic Ranges ◽  
Population Growth Rates ◽  
Range Edge ◽  
Outstanding Question

Species’ geographic ranges and climatic niches are likely to be increasingly mismatched due to rapid climate change. If a species’ range and niche are out of equilibrium, then population performance should decrease from high-latitude “leading” range edges, where populations are expanding into recently ameliorated habitats, to low-latitude “trailing” range edges, where populations are contracting from newly unsuitable areas. Demographic compensation is a phenomenon whereby declines in some vital rates are offset by increases in others across time or space. In theory, demographic compensation could increase the range of environments over which populations can succeed and forestall range contraction at trailing edges. An outstanding question is whether range limits and range contractions reflect inadequate demographic compensation across environmental gradients, causing population declines at range edges. We collected demographic data from 32 populations of the scarlet monkeyflower (Erythranthe cardinalis) spanning 11° of latitude in western North America and used integral projection models to evaluate population dynamics and assess demographic compensation across the species’ range. During the 5-y study period, which included multiple years of severe drought and warming, population growth rates decreased from north to south, consistent with leading-trailing dynamics. Southern populations at the trailing range edge declined due to reduced survival, growth, and recruitment, despite compensatory increases in reproduction and faster life-history characteristics. These results suggest that demographic compensation may only delay population collapse without the return of more favorable conditions or the contribution of other buffering mechanisms such as evolutionary rescue.

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