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Brown KT, Genin A, Mello‐Athayde MA, Bergstrom E, Campili A, Chai A, Dove SG, Ho M, Rowell D, Sampayo EM, Radice VZ. Marine heatwaves modulate the genotypic and physiological responses of reef-building corals to subsequent heat stress. Ecol Evol 2023; 13:e10798. [PMID: 38099138 PMCID: PMC10719612 DOI: 10.1002/ece3.10798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 11/21/2023] [Indexed: 12/17/2023] Open
Abstract
Back-to-back marine heatwaves in 2016 and 2017 resulted in severe coral bleaching and mortality across the Great Barrier Reef (GBR). Encouragingly, some corals that survived these events exhibit increased bleaching resistance and may represent thermally tolerant populations that can better cope with ocean warming. Using the GBR as a natural laboratory, we investigated whether a history of minimal (Heron Island) or severe (Lizard Island) coral bleaching in 2016 and 2017 equates to stress tolerance in a successive heatwave (2020). We examined the genetic diversity, physiological performance, and trophic plasticity of juvenile (<10 cm) and adult (>25 cm) corals of two common genera (Pocillopora and Stylophora). Despite enduring greater cumulative heat stress (6.3°C week-1 vs. 5.6°C week-1), corals that experienced the third marine heatwave in 5 years (Lizard) exhibited twice as high survival and visual bleaching thresholds compared to corals that had not experienced significant bleaching in >10 years (Heron). Surprisingly, only one shared host-Symbiodiniaceae association was uncovered between locations (Stylophora pistillata-Cladocopium "C8 group") and there was no genetic overlap in Pocillopora-Cladocopium partnerships, suggesting turnover in species composition from recent marine heatwaves. Corals within the species complex Pocillopora that survived the 2016 and 2017 marine heatwaves at Lizard Island were the most resilient, exhibiting three times greater calcification rates than conspecifics at Heron Island. Further, surviving corals (Lizard) had distinct isotopic niches, lower host carbon, and greater host protein, while conspecifics that had not experienced recent bleaching (Heron) had two times greater symbiont carbon content, suggesting divergent trophic strategies that influenced survival (i.e., greater reliance on heterotrophy vs. symbiont autotrophy, respectively). Ultimately, while corals may experience less bleaching and survive repeated thermal stress events, species-specific trade-offs do occur, leaving open many questions related to the long-term health and recovery of coral reef ecosystems in the face of intensifying marine heatwaves.
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Affiliation(s)
- Kristen T. Brown
- School of Biological SciencesUniversity of QueenslandSt LuciaQueenslandAustralia
- Department of BiologyUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Amatzia Genin
- The Interuniversity Institute for Marine Sciences of EilatThe Hebrew University of JerusalemEilatIsrael
| | | | | | - Adriana Campili
- Australian Institute of Marine ScienceTownsville Mail CentreTownsvilleQueenslandAustralia
| | - Aaron Chai
- Faculty of Science and EngineeringSouthern Cross UniversityEast LismoreNew South WalesAustralia
| | - Sophie G. Dove
- School of Biological SciencesUniversity of QueenslandSt LuciaQueenslandAustralia
| | | | - Devin Rowell
- School of Biological SciencesUniversity of QueenslandSt LuciaQueenslandAustralia
| | - Eugenia M. Sampayo
- School of Biological SciencesUniversity of QueenslandSt LuciaQueenslandAustralia
| | - Veronica Z. Radice
- School of Biological SciencesUniversity of QueenslandSt LuciaQueenslandAustralia
- Department of Biological SciencesOld Dominion UniversityNorfolkVirginiaUSA
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Bythell JC, Brown BE, Kirkwood TBL. Do reef corals age? Biol Rev Camb Philos Soc 2017; 93:1192-1202. [PMID: 29282837 DOI: 10.1111/brv.12391] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 11/17/2017] [Accepted: 11/23/2017] [Indexed: 01/13/2023]
Abstract
Hydra is emerging as a model organism for studies of ageing in early metazoan animals, but reef corals offer an equally ancient evolutionary perspective as well as several advantages, not least being the hard exoskeleton which provides a rich fossil record as well as a record of growth and means of ageing of individual coral polyps. Reef corals are also widely regarded as potentially immortal at the level of the asexual lineage and are assumed not to undergo an intrinsic ageing process. However, putative molecular indicators of ageing have recently been detected in reef corals. While many of the large massive coral species attain considerable ages (>600 years) there are other much shorter-lived species where older members of some populations show catastrophic mortality, compared to juveniles, under environmental stress. Other studies suggestive of ageing include those demonstrating decreased reproduction, increased susceptibility to oxidative stress and disease, reduced regeneration potential and declining growth rate in mature colonies. This review aims to promote interest and research in reef coral ageing, both as a useful model for the early evolution of ageing and as a factor in studies of ecological impacts on reef systems in light of the enhanced effects of environmental stress on ageing in other organisms.
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Affiliation(s)
- John C Bythell
- School of Natural & Environmental Sciences, Ridley Building, Newcastle University, Newcastle upon Tyne NE1 7RU, U.K
| | - Barbara E Brown
- School of Natural & Environmental Sciences, Ridley Building, Newcastle University, Newcastle upon Tyne NE1 7RU, U.K.,Environmental Research Unit, University of Highlands and Islands, Thurso KW14 7EE, U.K
| | - Thomas B L Kirkwood
- Institute for Ageing, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE4 5PL, U.K.,Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen 2200, Denmark
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3
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Ong RH, King AJC, Kaandorp JA, Mullins BJ, Caley MJ. The effect of allometric scaling in coral thermal microenvironments. PLoS One 2017; 12:e0184214. [PMID: 29023468 PMCID: PMC5638381 DOI: 10.1371/journal.pone.0184214] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 08/21/2017] [Indexed: 11/17/2022] Open
Abstract
A long-standing interest in marine science is in the degree to which environmental conditions of flow and irradiance, combined with optical, thermal and morphological characteristics of individual coral colonies, affects their sensitivity of thermal microenvironments and susceptibility to stress-induced bleaching within and/or among colonies. The physiological processes in Scleractinian corals tend to scale allometrically as a result of physical and geometric constraints on body size and shape. There is a direct relationship between scaling to thermal stress, thus, the relationship between allometric scaling and rates of heating and cooling in coral microenvironments is a subject of great interest. The primary aim of this study was to develop an approximation that predicts coral thermal microenvironments as a function of colony morphology (shape and size), light or irradiance, and flow velocity or regime. To do so, we provided intuitive interpretation of their energy budgets for both massive and branching colonies, and then quantified the heat-size exponent (b*) and allometric constant (m) using logarithmic linear regression. The data demonstrated a positive relationship between thermal rates and changes in irradiance, A/V ratio, and flow, with an interaction where turbulent regime had less influence on overall stress which may serve to ameliorate the effects of temperature rise compared to the laminar regime. These findings indicated that smaller corals have disproportionately higher stress, however they can reach thermal equilibrium quicker. Moreover, excellent agreements between the predicted and simulated microscale temperature values with no significant bias were observed for both the massive and branching colonies, indicating that the numerical approximation should be within the accuracy with which they could be measured. This study may assist in estimating the coral microscale temperature under known conditions of water flow and irradiance, in particular when examining the intra- and inter-colony variability found during periods of bleaching conditions.
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Affiliation(s)
- Robert H Ong
- Fluid Dynamics Research Group, Curtin Institute for Computation, Department of Mechanical Engineering, Curtin University, Perth, Australia
| | - Andrew J C King
- Fluid Dynamics Research Group, Curtin Institute for Computation, Department of Mechanical Engineering, Curtin University, Perth, Australia
| | - Jaap A Kaandorp
- Computational Science Section, University of Amsterdam, Amsterdam, The Netherlands
| | - Benjamin J Mullins
- Fluid Dynamics Research Group, Curtin Institute for Computation, Department of Mechanical Engineering, Curtin University, Perth, Australia.,Occupation and Environment, School of Public Health, Curtin University, Perth, Australia
| | - M Julian Caley
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia.,Australian Research Council Centre of Excellence for Mathematical and Statistical Frontiers, Victoria, Australia
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Age-Related Shifts in Bacterial Diversity in a Reef Coral. PLoS One 2015; 10:e0144902. [PMID: 26700869 PMCID: PMC4689413 DOI: 10.1371/journal.pone.0144902] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 11/24/2015] [Indexed: 01/19/2023] Open
Abstract
This study investigated the relationship between microbial communities in differently sized colonies of the massive coral Coelastrea aspera at Phuket, Thailand where colony size could be used as a proxy for age. Results indicated significant differences between the bacterial diversity (ANOSIM, R = 0.76, p = 0.001) of differently sized colonies from the same intertidal reef habitat. Juvenile and small colonies (<6cm mean diam) harboured a lower bacterial richness than medium (~10cm mean diam) and large colonies (>28 cm mean diam). Bacterial diversity increased in a step-wise pattern from juveniles<small<medium colonies, which was then followed by a slight decrease in the two largest size classes. These changes appear to resemble a successional process which occurs over time, similar to that observed in the ageing human gut. Furthermore, the dominant bacterial ribotypes present in the tissues of medium and large sized colonies of C. aspera, (such as Halomicronema, an Oscillospira and an unidentified cyanobacterium) were also the dominant ribotypes found within the endolithic algal band of the coral skeleton; a result providing some support for the hypothesis that the endolithic algae of corals may directly influence the bacterial community present in coral tissues.
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Tang CH, Ku PC, Lin CY, Chen TH, Lee KH, Lee SH, Wang WH. Intra-Colonial Functional Differentiation-Related Modulation of the Cellular Membrane in a Pocilloporid Coral Seriatopora caliendrum. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2015; 17:633-643. [PMID: 26242752 DOI: 10.1007/s10126-015-9645-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 06/06/2015] [Indexed: 06/04/2023]
Abstract
Scleractinian corals have displayed phenotypic gradients of polyps within a single genotypic colony, and this has profound implications for their biology. The intrinsic polymorphism of membrane lipids and the molecular interactions involved allow cells to dynamically organize their membranes to have physicochemical properties appropriate for their physiological requirements. To gain insight into the accommodation of the cellular membrane during ontogenetic shifts, intra-colony differences in the glycerophosphocholine profiling of a pocilloporid coral, Seriatopora caliendrum, were characterized using a previously validated method. Specifically, several major polyunsaturated phosphatidylcholines showed higher levels in the distal tissue of coral branches. In contrast, the corresponding molecules with 1-2-degree less unsaturation and plasmanylcholines were expressed more highly in the proximal tissue. The lipid profiles of these two colonial positions also contrasted sharply with regard to the saturated, monounsaturated, and lyso-glycerophosphocholine ratios. Based on the biochemical and biophysical properties of these lipids, the associated modulation of cellular membrane properties could be related to the physiological requirements, including coral growth and aging, of the functionally differentiated polyps. In this study, the metabolic regulation of membrane lipids involved in the functional differentiation of polyps within a S. caliendrum colony was identified.
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Affiliation(s)
- Chuan-Ho Tang
- Department of Biology, National Museum of Marine Biology and Aquarium, 2 Houwan Rd., Checheng, Pingtung, 944, Taiwan,
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Ross CL, Falter JL, Schoepf V, McCulloch MT. Perennial growth of hermatypic corals at Rottnest Island, Western Australia (32°S). PeerJ 2015; 3:e781. [PMID: 25755921 PMCID: PMC4349054 DOI: 10.7717/peerj.781] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 01/30/2015] [Indexed: 12/19/2022] Open
Abstract
To assess the viability of high latitude environments as coral refugia, we report measurements of seasonal changes in seawater parameters (temperature, light, and carbonate chemistry) together with calcification rates for two coral species, Acropora yongei and Pocillopora damicornis from the southernmost geographical limit of these species at Salmon Bay, Rottnest Island (32°S) in Western Australia. Changes in buoyant weight were normalised to colony surface areas as determined from both X-ray computed tomography and geometric estimation. Extension rates for A. yongei averaged 51 ± 4 mm y(-1) and were comparable to rates reported for Acroporid coral at other tropical and high latitude locations. Mean rates of calcification for both A. yongei and P. damicornis in winter were comparable to both the preceding and following summers despite a mean seasonal temperature range of ∼6 °C (18.2°-24.3 °C) and more than two-fold changes in the intensity of downwelling light. Seasonal calcification rates for A. yongei (1.31-2.02 mg CaCO3 cm(-2) d(-1)) and P. damicornis (0.34-0.90 mg CaCO3 cm(-2) d(-1)) at Salmon Bay, Rottnest Island were comparable to rates from similar taxa in more tropical environments; however, they appeared to decline sharply once summer temperatures exceeded 23 °C. A coral bleaching event observed in December 2013 provided further evidence of how coral at Rottnest Island are still vulnerable to the deleterious effects of episodic warming despite its high latitude location. Thus, while corals at Rottnest Island can sustain robust year-round rates of coral growth, even over cool winter temperatures of 18°-19 °C, there may be limits on the extent that such environments can provide refuge against the longer term impacts of anthropogenic climate change.
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Affiliation(s)
- Claire L. Ross
- UWA School of Earth and Environment and Oceans Institute, University of Western Australia, Crawley, Western Australia, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, University of Western Australia, Crawley, Western Australia, Australia
| | - James L. Falter
- UWA School of Earth and Environment and Oceans Institute, University of Western Australia, Crawley, Western Australia, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, University of Western Australia, Crawley, Western Australia, Australia
| | - Verena Schoepf
- UWA School of Earth and Environment and Oceans Institute, University of Western Australia, Crawley, Western Australia, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, University of Western Australia, Crawley, Western Australia, Australia
| | - Malcolm T. McCulloch
- UWA School of Earth and Environment and Oceans Institute, University of Western Australia, Crawley, Western Australia, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, University of Western Australia, Crawley, Western Australia, Australia
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Shantz AA, Burkepile DE. Context-dependent effects of nutrient loading on the coral–algal mutualism. Ecology 2014; 95:1995-2005. [DOI: 10.1890/13-1407.1] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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8
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Bulleri F, Couraudon-Réale M, Lison de Loma T, Claudet J. Variability in the effects of macroalgae on the survival and growth of corals: the consumer connection. PLoS One 2013; 8:e79712. [PMID: 24260290 PMCID: PMC3829870 DOI: 10.1371/journal.pone.0079712] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 10/04/2013] [Indexed: 11/17/2022] Open
Abstract
Shifts in dominance from corals to macroalgae are occurring in many coral reefs worldwide. Macroalgal canopies, while competing for space with coral colonies, may also form a barrier to herbivorous and corallivorous fish, offering protection to corals. Thus, corals could either suffer from enhanced competition with canopy-forming and understorey macroalgae or benefit from predator exclusion. Here, we tested the hypothesis that the effects of the brown, canopy-forming macroalga, Turbinaria ornata, on the survival and growth of corals can vary according to its cover, to the presence or absence of herbivorous and corallivorous fish and to the morphological types of corals. Over a period of 66 days, two coral species differing in growth form, Acropora pulchra and Porites rus, were exposed to three different covers of T. ornata (absent versus medium versus high), in the presence or absence of fish. Irrespective of the cover of T. ornata, fish exclusion reduced mortality rates of A. pulchra. Following fish exclusion, a high cover of T. ornata depressed the growth of this branched coral, whilst it had no effect when fish species were present. P. rus suffered no damage from corallivorous fish, but its growth was decreased by high covers of T. ornata, irrespective of the presence or absence of fish. These results show that negative effects of T. ornata on some coral species are subordinate to those of fish predation and are, therefore, likely to manifest only on reefs severely depleted of predators. In contrast, space dominance by T. ornata may decrease the growth of other coral species regardless of predation intensity. In general, this study shows that susceptibility to predation may determine the severity of the effects of canopy-forming macroalgae on coral growth.
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Affiliation(s)
- Fabio Bulleri
- Dipartimento di Biologia, Università di Pisa, Pisa, Italy
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White JSS, O'Donnell JL. Indirect effects of a key ecosystem engineer alter survival and growth of foundation coral species. Ecology 2011; 91:3538-48. [PMID: 21302826 DOI: 10.1890/09-2322.1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Stegastes nigricans, a "farmerfish" that cultivates algal turf and defends territories from grazers and other intruders, can affect coral indirectly due to increased competition with farmed algal turf and/or reduced predation resulting from territorial aggression directed at corallivores. To investigate the indirect effects of this key ecosystem engineer on coral mortality and growth, we transplanted caged and exposed fragments of four coral species to patch reefs in French Polynesia on which we manipulated the presence of S. nigricans and turf, and to reefs naturally devoid of S. nigricans. Reef access was two to four times higher for herbivorous fishes, and two times higher for corallivorous fishes, when S. nigricans was removed, indicating that reef access is reduced for two important guilds of fishes when S. nigricans is present. Stegastes' territoriality indirectly benefited delicate acroporids (Montipora floweri and Acropora striata), yielding a twofold to fivefold reduction in skeletal loss due to lower predation frequencies in the presence of S. nigricans. Three corals, A. striata, M. floweri, and especially Porites australiensis, suffered mortality due to overgrowth significantly more frequently in the presence of farmed turf, but Pocillopora verrucosa did not. Algal abundance predicted the frequency of overgrowth for only A. striata and P. australiensis. M. floweri were more likely to be overgrown when exposed (uncaged) in the presence of S. nigricans, suggesting an interaction modification, in this case that initial predation increased susceptibility to competition with turf. In this community, the presence of S. nigricans may increase algal overgrowth of massive Porites by facilitating its turf competitors and simultaneously reduce predation of branching corals through territorial exclusion of corallivores. These indirect interactions may underlie previously documented community transitions from disturbance-resistant massive coral to recovering branching corals within S. nigricans territories.
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Affiliation(s)
- Jada-Simone S White
- Department of Zoology, Box 118525, University of Florida, Gainesville, Florida 32611-8525, USA.
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Potential costs of acclimatization to a warmer climate: growth of a reef coral with heat tolerant vs. sensitive symbiont types. PLoS One 2010; 5:e10437. [PMID: 20454653 PMCID: PMC2862701 DOI: 10.1371/journal.pone.0010437] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Accepted: 03/18/2010] [Indexed: 11/18/2022] Open
Abstract
One of the principle ways in which reef building corals are likely to cope with a warmer climate is by changing to more thermally tolerant endosymbiotic algae (zooxanthellae) genotypes. It is highly likely that hosting a more heat-tolerant algal genotype will be accompanied by tradeoffs in the physiology of the coral. To better understand one of these tradeoffs, growth was investigated in the Indo-Pacific reef-building coral Acropora millepora in both the laboratory and the field. In the Keppel Islands in the southern Great Barrier Reef this species naturally harbors nrDNA ITS1 thermally sensitive type C2 or thermally tolerant type D zooxanthellae of the genus Symbiodinium and can change dominant type following bleaching. We show that under controlled conditions, corals with type D symbionts grow 29% slower than those with type C2 symbionts. In the field, type D colonies grew 38% slower than C2 colonies. These results demonstrate the magnitude of trade-offs likely to be experienced by this species as they acclimatize to warmer conditions by changing to more thermally tolerant type D zooxanthellae. Irrespective of symbiont genotype, corals were affected to an even greater degree by the stress of a bleaching event which reduced growth by more than 50% for up to 18 months compared to pre-bleaching rates. The processes of symbiont change and acute thermal stress are likely to act in concert on coral growth as reefs acclimatize to more stressful warmer conditions, further compromising their regeneration capacity following climate change.
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Abstract
Immobile plants and immobile modular animals outlive unitary animals. This paper discusses competing but not necessarily mutually exclusive theories to explain this extreme longevity, especially from the perspective of phenotypic plasticity. Stem cell immortality, vascular autonomy, and epicormic branching are some important features of the phenotypic plasticity of plants that contribute to their longevity. Monocarpy versus polycarpy can also influence the kind of senescent processes experienced by plants. How density-dependent phenomena affecting the establishment of juveniles in these immobile organisms can influence the evolution of senescence, and consequently longevity, is reviewed and discussed. Whether climate change scenarios will favour long-lived or short-lived organisms, with their attendant levels of plasticity, is also presented.
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Edmunds PJ. Temperature-mediated transitions between isometry and allometry in a colonial, modular invertebrate. Proc Biol Sci 2006; 273:2275-81. [PMID: 16928628 PMCID: PMC1636087 DOI: 10.1098/rspb.2006.3589] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The evolutionary success of animal design is strongly affected by scaling and virtually all metazoans are constrained by allometry. One body plan that appears to relax these constraints is a colonial modular (CM) design, in which modular iteration is hypothesized to support isometry and indeterminate colony size. In this study, growth rates of juvenile scleractinians (less than 40mm diameter) with a CM design were used to test this assertion using colony diameters recorded annually for a decade and scaling exponents (b) for growth calculated from double logarithmic plots of final versus initial diameters. For all juvenile corals, b differed significantly among years, with isometry (b=1) in 4 years, but positive allometry (b>1) in 5 years. The study years were characterized by differences in seawater temperature that were associated significantly with b for growth, with isometry in warm years but positive allometry in cool years. These results illustrate variable growth scaling in a CM taxon and suggest that the switch between scaling modes is mediated by temperature. For the corals studied, growth was not constrained by size, but this outcome was achieved through both isometry and positive allometry. Under cooler conditions, positive allometry may be beneficial as it represents a growth advantage that increases with size.
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Affiliation(s)
- Peter J Edmunds
- Department of Biology, California State University, Northridge, CA 91330-8303, USA.
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