1
|
Yen LP, Yong CLX, Todd PA. The effect of coral colony morphology, coral surface condition, particle size, and seeding point on the trapping and deposition of microplastics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 921:171077. [PMID: 38382597 DOI: 10.1016/j.scitotenv.2024.171077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 02/02/2024] [Accepted: 02/16/2024] [Indexed: 02/23/2024]
Abstract
Coral reefs are increasingly identified as microplastic sinks. Understanding the trapping and deposition effects on microplastics among coral colonies of different morphologies can help identify which corals and coral reefs are at higher risk of microplastic exposure. Here, we used a current-generating saltwater flume to explore microplastic trapping and deposition among branching coral, Pocillopora acuta, colonies with contrasting morphologies (open and compact), together with varying coral surface conditions (live, dead, and waxed), microplastic sizes (400 to 500 μm and 900 to 1000 μm), and seeding points (above-colony and mid-colony). Results revealed that more microplastics were trapped by, and deposited nearer to, compact colonies compared to those with a more open morphology-likely due to differences in flow dynamics. More of the larger microplastics were trapped, as were those introduced at the mid seeding point, but coral surface condition had no significant effect. These findings add to the growing evidence that corals are effective at trapping and facilitating deposition of microplastics. Branching corals with compact structures are potentially at high risk of microplastic pollution impact. We posit that coral composition, i.e. the relative abundance of compact branching colonies, will affect microplastic accumulation in natural reef environments. SYNOPSIS: This study demonstrates the effects of coral morphology on microplastic trapping and deposition, providing mechanistic insights into the factors that contribute to coral reefs acting as microplastic sinks.
Collapse
Affiliation(s)
- Li Peng Yen
- Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore
| | - Clara Lei Xin Yong
- Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore
| | - Peter A Todd
- Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore.
| |
Collapse
|
2
|
Blanchon P, Chutcharavan P. Meltwater Pulse 1a drowned fringing reefs around Tahiti 15 000 years ago. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230918. [PMID: 38094270 PMCID: PMC10716648 DOI: 10.1098/rsos.230918] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 11/21/2023] [Indexed: 12/21/2023]
Abstract
Reconstruction of postglacial sea-level rise using reef cores recovered from Tahiti during IODP Expedition 310 showed that the first major acceleration, known as Meltwater Pulse 1a (MWP-1a), was a 12-22 m rise in 340 years starting at 14.65 ka BP. Although it was reported that the pulse did not drown Tahitian reefs, the subsequent discovery of a fringing reef at the base of several cores implies that its timing, magnitude and impact require revision. Here, we report facies and paleodepth data from this reef, revise sea level, and revisit reef response. We find its reef crest is dominated by surf-adapted corals to a depth of 2.5 m and show that it retreated upslope over an approximately 1000-year interval from 16 ka. Reef development then apparently ceased at 15 ka at -106 m and remained absent for approximately 600 years, before resuming at 14.4 ka further upslope at -93 m. This absence is consistent with reef drowning and requires that MWP-1a had a smaller magnitude of 13.8 ± 1.3 m, and may have started 300 years earlier than previously reported. It confirms MWP-1a was a global event, drowning reefs on Tahiti as well as those in other oceans.
Collapse
Affiliation(s)
- Paul Blanchon
- Reef Geoscience Group, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Puerto Morelos, Mexico
| | - Peter Chutcharavan
- Department of Earth and Environmental Sciences, University of Minnesota Twin Cities, Minneapolis, USA
- Department of Geoscience, University of Wisconsin Madison, Madison, WI, USA
- Department of Geological Sciences, University of Florida, Gainesville, USA
| |
Collapse
|
3
|
Ferreira SB, Burns JHR, Pascoe KH, Kapono CA, Reyes AJ, Fukunaga A. Prediction of habitat complexity using a trait-based approach on coral reefs in Guam. Sci Rep 2023; 13:11095. [PMID: 37422484 PMCID: PMC10329656 DOI: 10.1038/s41598-023-38138-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 07/04/2023] [Indexed: 07/10/2023] Open
Abstract
Scleractinian corals are primary contributors to the structural complexity of coral reef ecosystems. The structure derived from their carbonate skeletons underpins the biodiversity and myriad of ecosystem services provided by coral reefs. This study used a trait-based approach to provide new insights into the relationships between habitat complexity and coral morphology. Three-Dimensional (3D) photogrammetry techniques were used to survey 208 study plots on the island of Guam, from which structural complexity metrics were derived and physical traits of corals were quantified. Three traits at the individual colony level (e.g., morphology, size, and genera) and two site-level environmental characteristics (e.g., wave exposure and substratum-habitat type) were examined. Standard taxonomy-based metrics were also included at the reef-plot level (e.g., coral abundance, richness, and diversity). Different traits disproportionately contributed to 3D metrics of habitat complexity. Larger colonies with a columnar morphology have the highest contribution to surface complexity, slope, and vector ruggedness measure, whereas branching and encrusting columnar colonies have the highest contribution to planform and profile curvature. These results highlight the importance of considering colony morphology and size in addition to conventional taxonomic metrics for the understanding and monitoring reef structural complexity. The approach presented here provides a framework for studies in other locations to predict the trajectory of reefs under changing environmental conditions.
Collapse
Affiliation(s)
- Sofia B Ferreira
- MEGA Lab, College of Natural and Health Sciences, University of Hawaii at Hilo, Hilo, HI, 96720, USA.
| | - John H R Burns
- MEGA Lab, College of Natural and Health Sciences, University of Hawaii at Hilo, Hilo, HI, 96720, USA
| | - Kailey H Pascoe
- MEGA Lab, College of Natural and Health Sciences, University of Hawaii at Hilo, Hilo, HI, 96720, USA
- Center for Global Discovery and Conservation Science, Arizona State University, Hilo, HI, 96720, USA
| | - Clifford A Kapono
- MEGA Lab, College of Natural and Health Sciences, University of Hawaii at Hilo, Hilo, HI, 96720, USA
- Center for Global Discovery and Conservation Science, Arizona State University, Hilo, HI, 96720, USA
| | - Andres J Reyes
- Marine Scientist, NAVFAC Systems Command Marianas, Joint Region Marianas, Santa Rita, GU, 96915, USA
| | - Atsuko Fukunaga
- MEGA Lab, College of Natural and Health Sciences, University of Hawaii at Hilo, Hilo, HI, 96720, USA
- Center for Global Discovery and Conservation Science, Arizona State University, Hilo, HI, 96720, USA
| |
Collapse
|
4
|
Oury N, Noël C, Mona S, Aurelle D, Magalon H. From genomics to integrative species delimitation? The case study of the Indo-Pacific Pocillopora corals. Mol Phylogenet Evol 2023; 184:107803. [PMID: 37120114 DOI: 10.1016/j.ympev.2023.107803] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 04/06/2023] [Accepted: 04/24/2023] [Indexed: 05/01/2023]
Abstract
With the advent of genomics, sequencing thousands of loci from hundreds of individuals now appears feasible at reasonable costs, allowing complex phylogenies to be resolved. This is particularly relevant for cnidarians, for which insufficient data is available due to the small number of currently available markers and obscures species boundaries. Difficulties in inferring gene trees and morphological incongruences further blur the study and conservation of these organisms. Yet, can genomics alone be used to delimit species? Here, focusing on the coral genus Pocillopora, whose colonies play key roles in Indo-Pacific reef ecosystems but have challenged taxonomists for decades, we explored and discussed the usefulness of multiple criteria (genetics, morphology, biogeography and symbiosis ecology) to delimit species of this genus. Phylogenetic inferences, clustering approaches and species delimitation methods based on genome-wide single-nucleotide polymorphisms (SNP) were first used to resolve Pocillopora phylogeny and propose genomic species hypotheses from 356 colonies sampled across the Indo-Pacific (western Indian Ocean, tropical southwestern Pacific and south-east Polynesia). These species hypotheses were then compared to other lines of evidence based on genetic, morphology, biogeography and symbiont associations. Out of 21 species hypotheses delimited by genomics, 13 were strongly supported by all approaches, while six could represent either undescribed species or nominal species that have been synonymised incorrectly. Altogether, our results support (1) the obsolescence of macromorphology (i.e., overall colony and branches shape) but the relevance of micromorphology (i.e., corallite structures) to refine Pocillopora species boundaries, (2) the relevance of the mtORF (coupled with other markers in some cases) as a diagnostic marker of most species, (3) the requirement of molecular identification when species identity of colonies is absolutely necessary to interpret results, as morphology can blur species identification in the field, and (4) the need for a taxonomic revision of the genus Pocillopora. These results give new insights into the usefulness of multiple criteria for resolving Pocillopora, and more widely, scleractinian species boundaries, and will ultimately contribute to the taxonomic revision of this genus and the conservation of its species.
Collapse
Affiliation(s)
- Nicolas Oury
- UMR ENTROPIE (Université de La Réunion, IRD, IFREMER, Université de Nouvelle-Calédonie, CNRS), Université de La Réunion, St Denis, La Réunion, France; Laboratoire Cogitamus, Paris, France.
| | - Cyril Noël
- IFREMER - IRSI - Service de Bioinformatique (SeBiMER), Plouzané, France
| | - Stefano Mona
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, EPHE-PSL, Université PSL, CNRS, SU, UA, Paris, France; EPHE, PSL Research University, Paris, France; Laboratoire d'Excellence CORAIL, Perpignan, France
| | - Didier Aurelle
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, EPHE-PSL, Université PSL, CNRS, SU, UA, Paris, France; Aix Marseille Université, Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | - Hélène Magalon
- UMR ENTROPIE (Université de La Réunion, IRD, IFREMER, Université de Nouvelle-Calédonie, CNRS), Université de La Réunion, St Denis, La Réunion, France; Laboratoire Cogitamus, Paris, France; Laboratoire d'Excellence CORAIL, Perpignan, France
| |
Collapse
|
5
|
Kramer N, Guan J, Chen S, Wangpraseurt D, Loya Y. Morpho-functional traits of the coral Stylophora pistillata enhance light capture for photosynthesis at mesophotic depths. Commun Biol 2022; 5:861. [PMID: 36002592 PMCID: PMC9402581 DOI: 10.1038/s42003-022-03829-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 08/10/2022] [Indexed: 12/03/2022] Open
Abstract
The morphological architecture of photosynthetic corals modulates the light capture and functioning of the coral-algal symbiosis on shallow-water corals. Since corals can thrive on mesophotic reefs under extreme light-limited conditions, we hypothesized that microskeletal coral features enhance light capture under low-light environments. Utilizing micro-computed tomography scanning, we conducted a novel comprehensive three-dimensional (3D) assessment of the small-scale skeleton morphology of the depth-generalist coral Stylophora pistillata collected from shallow (4–5 m) and mesophotic (45–50 m) depths. We detected a high phenotypic diversity between depths, resulting in two distinct morphotypes, with calyx diameter, theca height, and corallite marginal spacing contributing to most of the variation between depths. To determine whether such depth-specific morphotypes affect coral light capture and photosynthesis on the corallite scale, we developed 3D simulations of light propagation and photosynthesis. We found that microstructural features of corallites from mesophotic corals provide a greater ability to use solar energy under light-limited conditions; while corals associated with shallow morphotypes avoided excess light through self-shading skeletal architectures. The results from our study suggest that skeleton morphology plays a key role in coral photoadaptation to light-limited environments. Micro-computed tomography scanning and 3D light simulation models reveals distinct morphotypes of the coral species Stylophora pistillata depending on depth, and suggest that coral skeletal micromorphology plays a key role in coral photoadaptation.
Collapse
Affiliation(s)
- Netanel Kramer
- School of Zoology, Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel.
| | - Jiaao Guan
- Department of Electrical and Computer Engineering, University of California San Diego, San Diego, USA
| | - Shaochen Chen
- Department of Nanoengineering, University of California San Diego, San Diego, USA
| | - Daniel Wangpraseurt
- Department of Nanoengineering, University of California San Diego, San Diego, USA.,Scripps Institution of Oceanography, University of California San Diego, San Diego, USA
| | - Yossi Loya
- School of Zoology, Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel
| |
Collapse
|
6
|
Chiazzari B, Magalon H, Gélin P, Macdonald A. Living on the edge: Assessing the diversity of South African Pocillopora on the margins of the Southwestern Indian Ocean. PLoS One 2019; 14:e0220477. [PMID: 31374077 PMCID: PMC6677312 DOI: 10.1371/journal.pone.0220477] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 07/16/2019] [Indexed: 11/19/2022] Open
Abstract
Scleractinia of the Maputaland reef complex (MRC) in South Africa exist at the margins of the Western Indian Ocean (WIO) coral distribution and are the only substantial hermatypic coral communities in South Africa. Pocillopora species occupy a conspicuous component of the MRC, and previous investigations identified three species of Pocillopora utilizing conventional taxonomy. Thus, our aims were four-fold: to elucidate Pocillopora species diversity using genetic techniques, primarily using species delimitation methods based on the ORF gene; to test for the presence of hybridisation within the Pocillopora community on the South-West margin of distribution in the Indian Ocean using two nuclear and two mitochondrial markers; to test the presence of cryptic species, using 13 microsatellite markers, finally, to elucidate the degree of genetic diversity within each Pocillopora species found and compare this to communities in lower latitudes. We illustrate taxonomic inconsistencies between these inventories and our phylogenetic data. The MRC harbours unique populations of Pocillopora, consisting of three species hypothetically co-occurring throughout the south WIO, namely: P. meandrina/P. eydouxi, commonly misidentified as P. verrucosa, P. verrucosa, sometimes correctly identified, but also commonly misidentified as P. damicornis sensu lato, and P. villosa, almost always misidentified as P. eydouxi. The hypothesis that hybrid swarms of Pocillopora occur in marginal environments such as the MRC was not supported, with low levels of introgressive hybridization reported instead. Analyses illustrate low genetic diversity at the species and population resolutions, suggesting a small founder population for each species. Nevertheless, these populations are demographically unique, exhibiting high levels of ITS2 haplotype endemism compared to higher latitude populations and the rest of the WIO. Pocillopora diversity on the MRC represents a unique assemblage and warrants further protection.
Collapse
Affiliation(s)
- Brent Chiazzari
- School of Life Sciences, University of KwaZulu-Natal, Westville, KwaZulu-Natal, South Africa
| | - Hélène Magalon
- UMR ENTROPIE (Université de La Réunion, IRD, CNRS), Laboratoire d’excellence CORAIL, Faculté des Sciences et Technologies, La Réunion, France
| | - Pauline Gélin
- UMR ENTROPIE (Université de La Réunion, IRD, CNRS), Laboratoire d’excellence CORAIL, Faculté des Sciences et Technologies, La Réunion, France
| | - Angus Macdonald
- School of Life Sciences, University of KwaZulu-Natal, Westville, KwaZulu-Natal, South Africa
| |
Collapse
|
7
|
Soto D, De Palmas S, Ho MJ, Denis V, Chen CA. Spatial variation in the morphological traits of Pocillopora verrucosa along a depth gradient in Taiwan. PLoS One 2018; 13:e0202586. [PMID: 30118513 PMCID: PMC6097691 DOI: 10.1371/journal.pone.0202586] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/06/2018] [Indexed: 11/18/2022] Open
Abstract
Pocillopora verrucosa is a widely distributed depth-generalist coral that presents plasticity in its skeletal macro- and microstructure in response to environmental gradients. Light and water movement, which covary with depth, are the main environmental drivers of morphological plasticity in this genus; however, assessing environmentally-induced plasticity may be confounded by the extent of interspecific variation in Pocillopora. We examine the morphology of 8 typed P. verrucosa specimens collected along a depth gradient ranging from 7 to 45 meters and comprising 3 sites throughout Ludao, Taiwan. We measured 36 morphological characters, 14 which are novel, in 3 regions on the corallum-the apex, branch and base-in order to quantify their relationship to site and depth. We found significant correlation between depth and 19 morphological characters, notably branch verruca area, branch verruca height, base verruca spacing, base spinule length, and branch corallite area. 60% of microstructural characters and 25% of macrostructural characters showed a correlative relation to depth, suggesting that depth acclimatization is manifested primarily at the microstructural level. Canonical discriminant analysis of all morphometric characters by depth supports clustering into 3 groups: an overlapping 7m and 15m group, a 23-30m group, and a 38-45m group. Canonical discriminant analysis by site supports clustering into low- and high-current sites, differentiated primarily by branch septa width, base septa width, pre-terminal branch width, terminal branch maximum length, and terminal branch minimum length. We conclude that distinctive patterns of morphological variation in mesophotic specimens of P. verrucosa could reflect the effects of abiotic parameters such as light and water flow. Elucidating the mechanisms behind the morphological changes that occur in response to environmental gradients can help clarify the role that physiological plasticity plays in the acclimatization of corals to the unique environmental settings of mesophotic coral ecosystems.
Collapse
Affiliation(s)
- Derek Soto
- Biodiversity Program, Taiwan International Graduate Program, Academia Sinica and National Taiwan Normal University, Taipei, Taiwan
- Department of Life Science, National Taiwan Normal University, Taipei, Taiwan
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Stephane De Palmas
- Biodiversity Program, Taiwan International Graduate Program, Academia Sinica and National Taiwan Normal University, Taipei, Taiwan
- Department of Life Science, National Taiwan Normal University, Taipei, Taiwan
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Ming Jay Ho
- Biodiversity Program, Taiwan International Graduate Program, Academia Sinica and National Taiwan Normal University, Taipei, Taiwan
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
- Green Island Marine Research Station, Academia Sinica, Ludao, Taiwan
| | - Vianney Denis
- Institute of Oceanography, National Taiwan University, Taipei, Taiwan
| | - Chaolun Allen Chen
- Biodiversity Program, Taiwan International Graduate Program, Academia Sinica and National Taiwan Normal University, Taipei, Taiwan
- Department of Life Science, National Taiwan Normal University, Taipei, Taiwan
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
- Institute of Oceanography, National Taiwan University, Taipei, Taiwan
| |
Collapse
|
8
|
Johnston EC, Forsman ZH, Toonen RJ. A simple molecular technique for distinguishing species reveals frequent misidentification of Hawaiian corals in the genus Pocillopora. PeerJ 2018; 6:e4355. [PMID: 29441239 PMCID: PMC5807929 DOI: 10.7717/peerj.4355] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 01/20/2018] [Indexed: 12/25/2022] Open
Abstract
Species within the scleractinian genus Pocillopora Lamarck 1816 exhibit extreme phenotypic plasticity, making identification based on morphology difficult. However, the mitochondrial open reading frame (mtORF) marker provides a useful genetic tool for identification of most species in this genus, with a notable exception of P. eydouxi and P. meandrina. Based on recent genomic work, we present a quick and simple, gel-based restriction fragment length polymorphism (RFLP) method for the identification of all six Pocillopora species occurring in Hawai‘i by amplifying either the mtORF region, a newly discovered histone region, or both, and then using the restriction enzymes targeting diagnostic sequences we unambiguously identify each species. Using this approach, we documented frequent misidentification of Pocillopora species based on colony morphology. We found that P. acuta colonies are frequently mistakenly identified as P. damicornis in Kāne‘ohe Bay, O‘ahu. We also found that P. meandrina likely has a northern range limit in the Northwest Hawaiian Islands, above which P. ligulata was regularly mistaken for P. meandrina.
Collapse
Affiliation(s)
- Erika C Johnston
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, United States of America
| | - Zac H Forsman
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, United States of America
| | - Robert J Toonen
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, United States of America
| |
Collapse
|
9
|
Gélin P, Fauvelot C, Bigot L, Baly J, Magalon H. From population connectivity to the art of striping Russian dolls: the lessons from Pocillopora corals. Ecol Evol 2018; 8:1411-1426. [PMID: 29375807 PMCID: PMC5773318 DOI: 10.1002/ece3.3747] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 10/25/2017] [Accepted: 10/27/2017] [Indexed: 01/01/2023] Open
Abstract
Here, we examined the genetic variability in the coral genus Pocillopora, in particular within the Primary Species Hypothesis PSH09, identified by Gélin, Postaire, Fauvelot and Magalon (2017) using species delimitation methods [also named Pocillopora eydouxi/meandrina complex sensu, Schmidt-Roach, Miller, Lundgren, & Andreakis (2014)] and which was found to split into three secondary species hypotheses (SSH09a, SSH09b, and SSH09c) according to assignment tests using multi-locus genotypes (13 microsatellites). From a large sampling (2,507 colonies) achieved in three marine provinces [Western Indian Ocean (WIO), Tropical Southwestern Pacific (TSP), and Southeast Polynesia (SEP)], genetic structuring analysis conducted with two clustering analyses (structure and DAPC) using 13 microsatellites revealed that SSH09a was restricted to the WIO while SSH09b and SSH09c were almost exclusively in the TSP and SEP. More surprisingly, each SSH split into two to three genetically differentiated clusters, found in sympatry at the reef scale, leading to a pattern of nested hierarchical levels (PSH > SSH > cluster), each level hiding highly differentiated genetic groups. Thus, rather than structured populations within a single species, these three SSHs, and even the eight clusters, likely represent distinct genetic lineages engaged in a speciation process or real species. The issue is now to understand which hierarchical level (SSH, cluster, or even below) corresponds to the species one. Several hypotheses are discussed on the processes leading to this pattern of mixed clusters in sympatry, evoking formation of reproductive barriers, either by allopatric speciation or habitat selection.
Collapse
Affiliation(s)
- Pauline Gélin
- UMR ENTROPIE (Université de La Réunion, IRD, CNRS)Université de La RéunionSt DenisLa Réunion
- Laboratoire d'excellence‐CORAILPerpignanFrance
| | - Cécile Fauvelot
- Laboratoire d'excellence‐CORAILPerpignanFrance
- UMR ENTROPIE (IRD, Université de La Réunion, CNRS)Centre IRD de NouméaNoumeaNew Caledonia
- Present address:
Université Côte d'AzurCNRSNiceFrance
| | - Lionel Bigot
- UMR ENTROPIE (Université de La Réunion, IRD, CNRS)Université de La RéunionSt DenisLa Réunion
- Laboratoire d'excellence‐CORAILPerpignanFrance
| | - Joseph Baly
- Laboratoire d'excellence‐CORAILPerpignanFrance
- UMR ENTROPIE (IRD, Université de La Réunion, CNRS)Centre IRD de NouméaNoumeaNew Caledonia
| | - Hélène Magalon
- UMR ENTROPIE (Université de La Réunion, IRD, CNRS)Université de La RéunionSt DenisLa Réunion
- Laboratoire d'excellence‐CORAILPerpignanFrance
| |
Collapse
|
10
|
Smith H, Epstein H, Torda G. The molecular basis of differential morphology and bleaching thresholds in two morphs of the coral Pocillopora acuta. Sci Rep 2017; 7:10066. [PMID: 28855618 PMCID: PMC5577224 DOI: 10.1038/s41598-017-10560-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 08/10/2017] [Indexed: 11/24/2022] Open
Abstract
Processes of cnidarian evolution, including hybridization and phenotypic plasticity, have complicated the clear diagnosis of species boundaries within the phylum. Pocillopora acuta, a species of scleractinian coral that was recently split from the widespread Pocillopora damicornis species complex, occurs in at least two distinct morphs on the Great Barrier Reef. Contrasting morphology combined with evidence of differential bleaching thresholds among sympatrically distributed colonies suggest that the taxonomy of this recently described species is not fully resolved and may represent its own species complex. To examine the basis of sympatric differentiation between the two morphs, we combined analyses of micro- and macro-skeletal morphology with genome wide sequencing of the coral host, as well as ITS2 genotyping of the associated Symbiodinium communities. We found consistent differences between morphs on both the macro- and micro-skeletal scale. In addition, we identified 18 candidate functional genes that relate to skeletal formation and morphology that may explain how the two morphs regulate growth to achieve their distinct growth forms. With inconclusive results in endosymbiotic algal community diversity between the two morphs, we propose that colony morphology may be linked to bleaching susceptibility. We conclude that cryptic speciation may be in the early stages within the species P. acuta.
Collapse
Affiliation(s)
- Hillary Smith
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia. .,Australian Institute of Marine Science, PMB 3, Townsville, Queensland 4810, Australia. .,College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia. .,AIMS@JCU, James Cook University, Townsville, Queensland 4811, Australia.
| | - Hannah Epstein
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia.,Australian Institute of Marine Science, PMB 3, Townsville, Queensland 4810, Australia.,College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia.,AIMS@JCU, James Cook University, Townsville, Queensland 4811, Australia
| | - Gergely Torda
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia.,Australian Institute of Marine Science, PMB 3, Townsville, Queensland 4810, Australia
| |
Collapse
|
11
|
Johnston EC, Forsman ZH, Flot JF, Schmidt-Roach S, Pinzón JH, Knapp ISS, Toonen RJ. A genomic glance through the fog of plasticity and diversification in Pocillopora. Sci Rep 2017; 7:5991. [PMID: 28729652 PMCID: PMC5519588 DOI: 10.1038/s41598-017-06085-3] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 06/07/2017] [Indexed: 01/01/2023] Open
Abstract
Scleractinian corals of the genus Pocillopora (Lamarck, 1816) are notoriously difficult to identify morphologically with considerable debate on the degree to which phenotypic plasticity, introgressive hybridization and incomplete lineage sorting obscure well-defined taxonomic lineages. Here, we used RAD-seq to resolve the phylogenetic relationships among seven species of Pocillopora represented by 15 coral holobiont metagenomic libraries. We found strong concordance between the coral holobiont datasets, reads that mapped to the Pocillopora damicornis (Linnaeus, 1758) transcriptome, nearly complete mitochondrial genomes, 430 unlinked high-quality SNPs shared across all Pocillopora taxa, and a conspecificity matrix of the holobiont dataset. These datasets also show strong concordance with previously published clustering of the mitochondrial clades based on the mtDNA open reading frame (ORF). We resolve seven clear monophyletic groups, with no evidence for introgressive hybridization among any but the most recently derived sister species. In contrast, ribosomal and histone datasets, which are most commonly used in coral phylogenies to date, were less informative and contradictory to these other datasets. These data indicate that extant Pocillopora species diversified from a common ancestral lineage within the last ~3 million years. Key to this evolutionary success story may be the high phenotypic plasticity exhibited by Pocillopora species.
Collapse
Affiliation(s)
- Erika C Johnston
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, 96744, USA.
| | - Zac H Forsman
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, 96744, USA
| | - Jean-François Flot
- Université libre de Bruxelles (ULB), Avenue F.D. Roosevelt 50, B-1050, Bruxelles, Belgium
| | - Sebastian Schmidt-Roach
- Australian Institute of Marine Science, 4810, Townsville, Australia
- Carl von Ossietzky University of Oldenburg, 26129, Oldenburg, Germany
| | - Jorge H Pinzón
- Department of Psychiatry, UT Southwestern Medical Center, Dallas, TX, USA
| | - Ingrid S S Knapp
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, 96744, USA
| | - Robert J Toonen
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, 96744, USA
| |
Collapse
|
12
|
Tortolero-Langarica JDJA, Rodríguez-Troncoso AP, Cupul-Magaña AL, Carricart-Ganivet JP. Calcification and growth rate recovery of the reef-building Pocillopora species in the northeast tropical Pacific following an ENSO disturbance. PeerJ 2017; 5:e3191. [PMID: 28413732 PMCID: PMC5390766 DOI: 10.7717/peerj.3191] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 03/16/2017] [Indexed: 12/02/2022] Open
Abstract
Pocilloporids are one of the major reef-building corals in the eastern tropical Pacific (ETP) and also the most affected by thermal stress events, mainly those associated with El Niño/Southern Oscillation (ENSO) periods. To date, coral growth parameters have been poorly reported in Pocillopora species in the northeastern region of the tropical Pacific. Monthly and annual growth rates of the three most abundant morphospecies (P. cf. verrucosa, P. cf. capitata, and P. cf. damicornis) were evaluated during two annual periods at a site on the Pacific coast of Mexico. The first annual period, 2010–2011 was considered a strong ENSO/La Niña period with cool sea surface temperatures, then followed by a non-ENSO period in 2012–2013. The linear extension rate, skeletal density, and calcification rate averaged (±SD) were 2.31 ± 0.11 cm yr−1, 1.65 ± 0.18 g cm−3, 5.03 ± 0.84 g cm−2 yr-1 respectively, during the strong ENSO event. In contrast, the respective non-ENSO values were 3.50 ± 0.64 cm yr−1, 1.70 ± 0.18 g cm−3, and 6.02 ± 1.36 g cm−2 yr−1. This corresponds to 52% and 20% faster linear extension and calcification rates, respectively, during non-ENSO period. The evidence suggests that Pocillopora branching species responded positively with faster growth rates following thermal anomalies, which allow them to maintain coral communities in the region.
Collapse
Affiliation(s)
- Jose de Jesús A Tortolero-Langarica
- Laboratorio de Zoología Marina, Tecnológico Nacional de México, Instituto Tecnológico de Bahía de Banderas, Bahía de Banderas, Nayarit, México.,Laboratorio de Ecología Marina, Centro de Investigaciones Costeras, Centro Universitario de la Costa, Universidad de Guadalajara, Puerto Vallarta, Jalisco, México
| | - Alma P Rodríguez-Troncoso
- Laboratorio de Ecología Marina, Centro de Investigaciones Costeras, Centro Universitario de la Costa, Universidad de Guadalajara, Puerto Vallarta, Jalisco, México
| | - Amílcar L Cupul-Magaña
- Laboratorio de Ecología Marina, Centro de Investigaciones Costeras, Centro Universitario de la Costa, Universidad de Guadalajara, Puerto Vallarta, Jalisco, México
| | - Juan P Carricart-Ganivet
- Unidad Académica de Sistemas Arrecifales, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, México
| |
Collapse
|
13
|
Gélin P, Postaire B, Fauvelot C, Magalon H. Reevaluating species number, distribution and endemism of the coral genus Pocillopora Lamarck, 1816 using species delimitation methods and microsatellites. Mol Phylogenet Evol 2017; 109:430-446. [PMID: 28219759 DOI: 10.1016/j.ympev.2017.01.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Revised: 01/25/2017] [Accepted: 01/30/2017] [Indexed: 01/06/2023]
Abstract
Species delimitation methods based on genetic information, notably using single locus data, have been proposed as means of increasing the rate of biodiversity description, but can also be used to clarify complex taxonomies. In this study, we explore the species diversity within the cnidarian genus Pocillopora, widely distributed in the tropical belt of the Indo-Pacific Ocean. From 943 Pocillopora colonies sampled in the Western Indian Ocean, the Tropical Southwestern Pacific and Southeast Polynesia, representing a huge variety of morphotypes, we delineated Primary Species Hypotheses (PSH) applying the Automatic Barcode Gap Discovery method, the Poisson Tree Processes algorithm and the Generalized mixed Yule-coalescent model on two mitochondrial markers (Open Reading Frame and Dloop) and reconstructing a haploweb using one nuclear marker (Internal Transcribed Spacer 2). Then, we confronted identified PSHs to the results of clustering analyses using 13 microsatellites to determine Secondary Species Hypotheses (SSH). Based on the congruence of all methods used and adding sequences from the literature, we defined at least 18 Secondary Species Hypotheses among 14 morphotypes, confirming the high phenotypic plasticity in Pocillopora species and the presence of cryptic lineages. We also identified three new genetic lineages never found to date, which could represent three new putative species. Moreover, the biogeographical ranges of several SSHs were re-assessed in the light of genetic data, which may have direct implications in conservation policies. Indeed, the cryptic diversity within this genus should be taken into account seriously, as neglecting its importance is source of confusion in our understanding of ecosystem functioning. Next generation sequencing, combined with other parameters (i.e. microstructure, zooxanthellae identification, ecology even at a micro-scale, resistance and resilience ability to bleaching) will be the next step towards an integrative framework of Pocillopora taxonomy, which will have profound implications for ecological studies, such as studying biodiversity, response to global warming and symbiosis.
Collapse
Affiliation(s)
- P Gélin
- UMR ENTROPIE (Université de La Réunion, IRD, CNRS), Laboratoire d'excellence-CORAIL, Faculté des Sciences et Technologies, 15 Bd René Cassin, CS 92003, 97744 St Denis Cedex 09, La Réunion, France
| | - B Postaire
- UMR ENTROPIE (Université de La Réunion, IRD, CNRS), Laboratoire d'excellence-CORAIL, Faculté des Sciences et Technologies, 15 Bd René Cassin, CS 92003, 97744 St Denis Cedex 09, La Réunion, France
| | - C Fauvelot
- UMR ENTROPIE (IRD, Université de La Réunion, CNRS), Laboratoire d'excellence-CORAIL, Centre IRD de Nouméa, 101 Promenade Roger Laroque, BP A5, 98848 Nouméa cedex, New Caledonia
| | - H Magalon
- UMR ENTROPIE (Université de La Réunion, IRD, CNRS), Laboratoire d'excellence-CORAIL, Faculté des Sciences et Technologies, 15 Bd René Cassin, CS 92003, 97744 St Denis Cedex 09, La Réunion, France.
| |
Collapse
|
14
|
Neustupa J. Asymmetry and integration of cellular morphology in Micrasterias compereana. BMC Evol Biol 2017; 17:1. [PMID: 28049419 PMCID: PMC5209845 DOI: 10.1186/s12862-016-0855-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 12/17/2016] [Indexed: 01/07/2023] Open
Abstract
Background Unicellular green algae of the genus Micrasterias (Desmidiales) have complex cells with multiple lobes and indentations, and therefore, they are considered model organisms for research on plant cell morphogenesis and variation. Micrasterias cells have a typical biradial symmetric arrangement and multiple terminal lobules. They are composed of two semicells that can be further differentiated into three structural components: the polar lobe and two lateral lobes. Experimental studies suggested that these cellular parts have specific evolutionary patterns and develop independently. In this study, different geometric morphometric methods were used to address whether the semicells of Micrasterias compereana are truly not integrated with regard to the covariation of their shape data. In addition, morphological integration within the semicells was studied to ascertain whether individual lobes constitute distinct units that may be considered as separate modules. In parallel, I sought to determine whether the main components of morphological asymmetry could highlight underlying cytomorphogenetic processes that could indicate preferred directions of variation, canalizing evolutionary changes in cellular morphology. Results Differentiation between opposite semicells constituted the most prominent subset of cellular asymmetry. The second important asymmetric pattern, recovered by the Procrustes ANOVA models, described differentiation between the adjacent lobules within the quadrants. Other asymmetric components proved to be relatively unimportant. Opposite semicells were shown to be completely independent of each other on the basis of the partial least squares analysis analyses. In addition, polar lobes were weakly integrated with adjacent lateral lobes. Conversely, higher covariance levels between the two lateral lobes of the same semicell indicated mutual interconnection and significant integration between these parts. Conclusions Micrasterias cells are composed of several successively disintegrated parts. These integration patterns concurred with presumed scenarios of morphological evolution within the lineage. In addition, asymmetric differentiation in the shape of the lobules involves two major patterns: asymmetry across the isthmus axis and among the adjacent lobules. Notably, asymmetry among the adjacent lobules may be related to evolutionary differentiation among species, but it may also point out developmental instability related to environmental factors. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0855-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Jiří Neustupa
- Department of Botany, Faculty of Science, Charles University, Prague, Czech Republic.
| |
Collapse
|
15
|
Human Influences On Eastern Tropical Pacific Coral Communities and Coral Reefs. CORAL REEFS OF THE EASTERN TROPICAL PACIFIC 2017. [DOI: 10.1007/978-94-017-7499-4_20] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
16
|
Esteve-Altava B. In search of morphological modules: a systematic review. Biol Rev Camb Philos Soc 2016; 92:1332-1347. [DOI: 10.1111/brv.12284] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Revised: 05/06/2016] [Accepted: 05/10/2016] [Indexed: 12/25/2022]
Affiliation(s)
- Borja Esteve-Altava
- Department of Comparative Biomedical Sciences; Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
- Department of Anatomy; College of Medicine, Howard University; 520 W Street, NW, Numa Adams Building Washington DC 20059 USA
| |
Collapse
|
17
|
Paz-García DA, Hellberg ME, García-de-León FJ, Balart EF. Switch between Morphospecies of Pocillopora Corals. Am Nat 2015; 186:434-40. [DOI: 10.1086/682363] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|