scholarly journals High clonality in Acropora palmata and Acropora cervicornis populations of Guadeloupe, French Lesser Antilles

2015 ◽  
Vol 66 (9) ◽  
pp. 847 ◽  
Author(s):  
A. Japaud ◽  
C. Bouchon ◽  
J.-L. Manceau ◽  
C. Fauvelot

Since the 1980s, population densities of Acroporidae have dramatically declined in the Caribbean Sea. Quantitative censuses of Acroporidae provide information on the number of colonies (i.e. ramets), but not on the number of genetically distinct individuals (i.e. genets). In this context, the aim of our study was to provide an overview of the genetic status of Acropora populations in Guadeloupe by examining the genotypic richness of Acropora palmata and Acropora cervicornis. Using 14 microsatellite loci, we found extremely low genotypic richness for both species from Caye-à-Dupont reef (i.e. 0.125 for A. palmata and nearly zero for A. cervicornis). Because genetic diversity contributes to the ability of organisms to evolve and adapt to new environmental conditions, our results are alarming in the context of ongoing global warming as long periods of clonal growth without sexual recruitment may lead to the extinction of these populations.

1998 ◽  
Vol 25 (2) ◽  
pp. 122-130 ◽  
Author(s):  
TIMOTHY R. McCLANAHAN ◽  
NYAWIRA A. MUTHIGA

Many coral reefs in the Caribbean, and elsewhere, have undergone changes from hard coral to fleshy algal dominance over the past two decades which has often been interpreted as a localized response to eutrophication and fishing. Here, data on the abundance of hard corals and algae from lagoonal patch reefs distributed throughout a large (260 km2) remote reef atoll located approximately 30 km offshore from the sparsely-populated coast of Belize, Central America, are compared with a study of these patch reefs conducted 25 years previously. Data and observations indicate that these patch reefs have undergone a major change in their ecology associated with a 75% reduction in total hard coral, a 99% loss in the cover of Acropora cervicornis and A. palmata, and a 315% increase in algae, which are mostly erect brown algae species in the genera Lobophora, Dictyota, Turbinaria and Sargassum. Such changes have been reported from other Caribbean reefs during the 1980s, but not on such a remote reef and the present changes may be attributed primarily to both a disease that began killing Acropora in this region in the mid 1980s and a reduction in herbivory. The low level of herbivory may be attributable to the disease-induced loss of the sea urchin Diadema antillarum in 1983, or fishing of herbivorous fishes, but both explanations are speculative. The present density of fisherfolk is low, and their efforts are not targetted at herbivorous fishes, and population densities of D. antillarum 14 years after the mortality are <1 individual per 1000 m2, but there is no comparative data from before the die off. There is, however, no indication that these major changes occurred on the fore reef, because A. palmata is abundant and erect algal abundance is low. We suggest that reported changes in other Caribbean reefs are not necessarily or exclusively influenced by local human factors such as localized intense eutrophication or fishing.


Author(s):  
Jörn Geister

The windward reef complex NE and E of San Andrés Island is briefly described in terms of submarine topography, sediments and the distribution of corals and other benthonic organisms. The breaker zone of the San Andrés barrier and other exposed Western Caribbean reefs characteristically exhibits a profuse growth consisting almost exclusively of Millepora. In this respect they are different from most other described West Indian reef localities, where Acropora palmata is the dominating species in this part of the reef. The replacement of Acropora palmata by Millepora is interpreted as an adaptation of the reef crest community to high energy environments due to long swell prevailing at the Western end of the Caribbean Sea. A few short reef sections exposed to the maximum degree of wave energy show conspicuous algal ridges.


Zootaxa ◽  
2018 ◽  
Vol 4526 (1) ◽  
pp. 56
Author(s):  
MATHEUS V. LOPES ◽  
BÁSLAVI CÓNDOR-LUJÁN ◽  
FERNANDA AZEVEDO ◽  
THIERRY PÉREZ ◽  
MICHELLE KLAUTAU

Calcareous sponges from the Lesser Antilles were recently inventoried and several specimens morphologically resembling species of the genus Ascoleucetta were collected. Morphological and molecular (C-LSU and ITS) analyses indicated that these specimens from the Lesser Antilles constituted a new genus. They lack the conspicuous and very characteristic ornamentation of the inhalant apertures found in two out of three species of Ascoleucetta, including the type species A. compressa. In the molecular analyses, the specimens clustered as an independent lineage, distant from the clade of A. compressa. Based on these results, we decided to erect a new genus, Bidderia gen. nov., whose type species is Bidderia bicolora gen. nov. sp. nov. Considering this new discovery, we are proposing to transfer the species A. amitsba to the genus Bidderia gen. nov. and to rediagnose Ascoleucetta. 


2020 ◽  
Vol 6 (17) ◽  
pp. eaax9395 ◽  
Author(s):  
Katie L. Cramer ◽  
Jeremy B. C. Jackson ◽  
Mary K. Donovan ◽  
Benjamin J. Greenstein ◽  
Chelsea A. Korpanty ◽  
...  

The mass mortality of acroporid corals has transformed Caribbean reefs from coral- to macroalgal-dominated habitats since systematic monitoring began in the 1970s. Declines have been attributed to overfishing, pollution, sea urchin and coral disease, and climate change, but the mechanisms are unresolved due to the dearth of pre-1970s data. We used paleoecological, historical, and survey data to track Acropora presence and dominance throughout the Caribbean from the prehuman period to present. Declines in dominance from prehuman values first occurred in the 1950s for Acropora palmata and the 1960s for Acropora cervicornis, decades before outbreaks of acroporid disease or bleaching. We compared trends in Acropora dominance since 1950 to potential regional and local drivers. Human population negatively affected and consumption of fertilizer for agriculture positively affected A. palmata dominance, the latter likely due to lower human presence in agricultural areas. The earlier, local roots of Caribbean Acropora declines highlight the urgency of mitigating local human impacts.


PLoS ONE ◽  
2015 ◽  
Vol 10 (10) ◽  
pp. e0139192 ◽  
Author(s):  
Jada Benn Torres ◽  
Miguel G. Vilar ◽  
Gabriel A. Torres ◽  
Jill B. Gaieski ◽  
Ricardo Bharath Hernandez ◽  
...  

mBio ◽  
2019 ◽  
Vol 10 (6) ◽  
Author(s):  
Marcus M. Teixeira ◽  
Primavera Alvarado ◽  
Chandler C. Roe ◽  
George R. Thompson ◽  
José S. L. Patané ◽  
...  

ABSTRACT Coccidioides posadasii is a pathogenic fungus that causes coccidioidomycosis in many arid regions of the Americas. One of these regions is bordered by the Caribbean Sea, and the surrounding landscape may play an important role in the dispersion of C. posadasii across South America through southeastern Mexico, Honduras, Guatemala, and Venezuela. Comparative phylogenomic analyses of C. posadasii reveal that clinical strains from Venezuela are genetically distinct from the North American populations found in (i) Arizona and (ii) Texas, Mexico, and the rest of South America (TX/MX/SA). We find evidence for admixture between the Venezuela and the North American populations of C. posadasii in Central America. Additionally, the proportion of Venezuelan alleles in the admixed population decreases as latitude (and distance from Venezuela) increases. Our results indicate that the population in Venezuela may have been subjected to a recent bottleneck and shows a strong population structure. This analysis provides insight into potential for Coccidioides spp. to invade new regions. IMPORTANCE Valley Fever is a fungal disease caused by two species of fungi: Coccidioides immitis and C. posadasii. These fungi are found throughout the arid regions of North and South America; however, our understanding of genetic diversity and disease in South America is limited. In this report, we analyze 10 new genomes of Coccidioides posadasii from regions bordering the Caribbean Sea. We show that these populations are distinct and that isolates from Venezuela are likely a result of a recent bottleneck. These data point to patterns that might be observed when investigating recently established populations.


2007 ◽  
Vol 25 (2) ◽  
pp. 331-340 ◽  
Author(s):  
R. C. Cruz Gómez ◽  
S. N. Bulgakov

Abstract. The North Brazil Current Rings (NBCR) penetration into the Caribbean Sea is being investigated by employing a merged altimeter-derived sea height anomaly (TOPEX/Poseidon, Jason-1 and ERS-1, 2), the ocean surface color data (SeaWiFS) and Global Drifter Program information. Four strategies are being applied to process the data: (1) calculations of the Okubo-Weiss parameter for NBCR identification, (2) longitude-time plots (also known as Hovmöller diagrams), (3) two-dimensional Radon transforms and (4) two-dimensional Fourier transforms. A twofold NBCR structure has been detected in the region under investigation. The results have shown that NBC rings mainly propagate into the Caribbean Sea along two principal pathways (near 12° N and 17° N) in the ring translation corridor. Thus, rings following the southern pathway in the fall-winter period can enter through very shallow southern straits as non-coherent structures. A different behavior is observed near the northern pathway (~17° N), where NBC rings are thought to have a coherent structure during their squeezing into the eastern Caribbean, i.e. conserving the principal characteristics of the incident rings. We attribute this difference in the rings' behavior to the vertical scales of the rings and to the bottom topography features in the vicinity of the Lesser Antilles.


Coral Reefs ◽  
2021 ◽  
Author(s):  
Hannah F. Nylander-Asplin ◽  
Ronald L. Hill ◽  
Jennifer C. Doerr ◽  
Lisa Greer ◽  
Nicole D. Fogarty

AbstractAcropora cervicornis and A. palmata have experienced substantial losses in coral cover throughout the Caribbean, but their hybrid (A. prolifera) appears to be increasing at some sites. The shifts in relative abundance could result from hybridization with subsequent asexual fragmentation, recent increased hybridization, or a disproportionate loss in the parental species. Here, acroporid taxa from three U.S. Virgin Islands sites were genotyped revealing 35 hybrid genotypes, suggesting multiple hybridization events. Genotypic richness in A. cervicornis (0.62), A. prolifera (0.64), and A. palmata (0.68) was not significantly different across sites. To further explore acroporid dynamics at these sites, we analyzed existing photo transects from 2009 to 2017 to reveal significant losses of A. cervicornis but stable hybrid percent cover. High genotypic richness and stable populations suggest acroporid hybrids may become the primary shallow reef-builders in some locations previously occupied by the parental species.


Author(s):  
Abraham Anthony Chen ◽  
Trevor Falloon

The core of the West Indies consists of the archipelago of islands that stretches southeast from the Yucatan and Florida peninsulas to Venezuela. Generally the term “West Indies” is synonymous with the “Antilles” and is therefore often used to refer to the islands that compose the Greater and Lesser Antilles. The islands of the Greater Antilles include Cuba, Hispaniola, Puerto Rico, and Jamaica—all located in the north Caribbean Sea—while the Lesser Antilles encompasses the smaller islands found to the south and east. In total, the West Indies embraces about 25 island territories. There are complex mountain ranges in the Greater Antilles, such as the Blue Mountains (2257 m) in central Jamaica and the Pico Duarte (3175 m) in the Dominican Republic, smaller volcanic peaks in the northeast island arc, and low-lying islands composing the remainder of the Lesser Antilles. The variation in local topography contributes significantly to the general rainfall pattern across the West Indian islands, as the windward sides of the larger and more mountainous islands are rainy and windswept, while the leeward sides are drier. In comparison, the low-lying eastern islands receive much less rainfall due to their lack of topographic relief and are much more dependent on seasonal rains. It is, however, the location of the West Indian islands between the permanent high pressure zone of the subtropical north Atlantic (the Azores high) and the equatorial trough of low pressure that gives rise to the mean monthly West Indian rainfall depicted in figure 11.2. Early in the year (December through March) and for a brief period in July, the Caribbean is dominated by subsidence from the inner zone of the Azores high and is at its driest. Rainfall during this period (barring July) is largely from the intrusion of fronts from North America. By the onset of the rainy season, however, the Azores high drifts farther north, resulting in weakened trade winds. At the same time, the Caribbean Sea warms up.


Zootaxa ◽  
2008 ◽  
Vol 1878 (1) ◽  
pp. 1 ◽  
Author(s):  
HORIA R. GALEA

A recent collection of shallow-water hydroids from Guadeloupe and Les Saintes, in the eastern Caribbean Sea, was studied. This is the first comprehensive report on the hydroid fauna from the study area. A total of 48 species, belonging to 9 families of athecates and 12 families of thecates, are described or listed. All the species are illustrated and, when necessary, data on the cnidome composition are provided. Two new species, Zanclea migottoi sp. nov. and Halopteris vervoorti sp. nov., are described. Rhizogeton sterreri (Calder, 1988) is redescribed based on fertile material. Its taxonomic status is discussed and the genus Rhizodendrium Calder, 1988 is included in the synonymy of Rhizogeton L. Agassiz, 1862. Scandia michaelsarsi (Leloup, 1935) is believed to be a synonym of S. gigas (Pieper, 1884), and morphological arguments are provided to support this hypothesis. An undescribed type of peculiar gonothecae, arising from the hydrothecal apertures, was found in Dynamena disticha (Bosc, 1802). Sertularella peculiaris (Leloup, 1935) is redescribed and its synonymy discussed. The nematocyst types of Symmetroscyphus intermedius (Congdon, 1907) were identified. Some species in the present collection are provisionally identified or assigned to a genus, pending the discovery of fertile material or additional life cycle studies. Finally, the hydroid fauna from the study area proves to be preponderantly tropical in nature, with several species also occurring in temperate seas. A number of species are first records for the Caribbean basin: R. sterreri, Eudendrium capillare Alder, 1856, Coryne pusilla Gaertner, 1774, Halecium cf. lankesteri (Bourne, 1890), S. gigas, and Sertularia loculosa Busk, 1852.


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