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Barrows AR, Hancock JR, Cohen DL, Gorong P, Lewis M, Louie S, Musselman L, Caruso C, Miller S, Drury C. Enhancing survivorship and growth of juvenile Montipora capitata using the Hawaiian collector urchin Tripneustes gratilla. PeerJ 2023; 11:e16113. [PMID: 37790625 PMCID: PMC10542273 DOI: 10.7717/peerj.16113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 08/27/2023] [Indexed: 10/05/2023] Open
Abstract
The biodiversity of coral reef habitats is rapidly declining due to the effects of anthropogenic climate change, prompting the use of active restoration as a mitigation strategy. Sexual propagation can maintain or enhance genetic diversity in restoration of these ecosystems, but these approaches suffer from a range of inefficiencies in rearing and husbandry. Algal overgrowth of juveniles is a major bottleneck in the production of sexually propagated corals that may be alleviated by co-culture with herbivores. We reared juvenile Montipora capitata alongside juvenile native Hawaiian collector urchins, Tripneustes gratilla, for 15 weeks and documented significant ecological benefits of co-culture. Urchin treatments significantly increased the survivorship of coral aggregates (14%) and individual settlers (24%). We also documented a significant increase in coral growth in the presence of urchins. These results demonstrate the utility of microherbivory in promoting coral growth and survivorship in ex situ conditions, providing valuable insight for restoration pipelines of native Hawaiian coral species.
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Affiliation(s)
- Andrew R. Barrows
- Hawai‘i Institute of Marine Biology, University of Hawai‘i, Kāne‘ohe, HI, United States
| | - Joshua R. Hancock
- Hawai‘i Institute of Marine Biology, University of Hawai‘i, Kāne‘ohe, HI, United States
| | - David L. Cohen
- Department of Land and Natural Resources, Division of Aquatic Resources, Honolulu, Hawai‘i, United States
| | - Patrick Gorong
- Department of Land and Natural Resources, Division of Aquatic Resources, Honolulu, Hawai‘i, United States
| | - Matthew Lewis
- Department of Land and Natural Resources, Division of Aquatic Resources, Honolulu, Hawai‘i, United States
| | - Sean Louie
- Department of Land and Natural Resources, Division of Aquatic Resources, Honolulu, Hawai‘i, United States
| | - Lani Musselman
- Department of Land and Natural Resources, Division of Aquatic Resources, Honolulu, Hawai‘i, United States
| | - Carlo Caruso
- Hawai‘i Institute of Marine Biology, University of Hawai‘i, Kāne‘ohe, HI, United States
| | - Spencer Miller
- Hawai‘i Institute of Marine Biology, University of Hawai‘i, Kāne‘ohe, HI, United States
| | - Crawford Drury
- Hawai‘i Institute of Marine Biology, University of Hawai‘i, Kāne‘ohe, HI, United States
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Knapp IS, Forsman ZH, Greene A, Johnston EC, Bardin CE, Chan N, Wolke C, Gulko D, Toonen RJ. Coral micro-fragmentation assays for optimizing active reef restoration efforts. PeerJ 2022; 10:e13653. [PMID: 35873907 PMCID: PMC9302430 DOI: 10.7717/peerj.13653] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 06/08/2022] [Indexed: 01/17/2023] Open
Abstract
The global decline of coral reefs has driven considerable interest in active coral restoration. Despite their importance and dominance on mature reefs, relatively few coral restoration projects use slower growth forms like massive and encrusting coral species. Micro-fragmentation can increase coral cover by orders of magnitude faster than natural growth, which now allows cultivation of slow growing massive forms and shows promise and flexibility for active reef restoration. However, the major causes of variation in growth and survival of outplanted colonies remain poorly understood. Here, we report simple outplanting assays to aid in active reef restoration of slower growing species and increase the likelihood of restoration success. We used two different micro-fragmentation assays. Pyramid assays were used to examine variation associated with fragment size (ranging from ≈1-9 cm2), nursery residence time (for both in-situ and ex-situ nurseries), and 2D vs. 3D measurements of growth. Block assays were used to examine spatial variation among individual performance at outplanting sites in the field. We found 2D and 3D measurements correlated well, so measured survivorship and growth using top-down planar images for two of the main Hawaiian reef building corals, the plating Montipora capitata and the massive Porites compressa. Pyramid assays housed and outplanted from the in-situ nursery showed no effect of residence time or size on overall survivorship or growth for either species. Results from the ex-situ nursery, however, varied by species, with P. compressa again showing no effect of nursery residence time or size on survivorship or growth. In contrast, nursery culture resulted in improved survivorship of small M. capitata fragments, but net growth showed a weak positive effect of nursery time for medium fragments. Small fragments still suffered higher mortality than either medium or large fragments. Due to their lower mortality, medium fragments (≈3 cm2) appear to be the best compromise between growth and survivorship for outplanting. Likewise, given weak positive gains relative to the investment, our results suggest that it could be more cost-effective to simply outplant medium fragments as soon as possible, without intermediate culture in a nursery. Furthermore, the block assay revealed significant differences in survivorship and growth among sites for individuals of both species, emphasizing the importance of considering spatial variation in coral survival and growth following outplanting. These results highlight the value of using short-term micro-fragmentation assays prior to outplanting to assess size, and location specific performance, optimizing the efficiency of active reef restoration activities and maximizing the probability of success for active coral restoration projects.
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Affiliation(s)
- Ingrid S.S. Knapp
- Hawai'i Institute of Marine Biology, School of Ocean & Earth Sciences & Technology, University of Hawai'i at Mānoa, Moku o Lóe, Kānéohe, Hawai'i, USA
| | - Zac H. Forsman
- Hawai'i Institute of Marine Biology, School of Ocean & Earth Sciences & Technology, University of Hawai'i at Mānoa, Moku o Lóe, Kānéohe, Hawai'i, USA,Environmental Science and Monitoring, The Red Sea Development Company, Riyadh, Saudi Arabia
| | - Austin Greene
- Hawai'i Institute of Marine Biology, School of Ocean & Earth Sciences & Technology, University of Hawai'i at Mānoa, Moku o Lóe, Kānéohe, Hawai'i, USA
| | - Erika C. Johnston
- Hawai'i Institute of Marine Biology, School of Ocean & Earth Sciences & Technology, University of Hawai'i at Mānoa, Moku o Lóe, Kānéohe, Hawai'i, USA,Department of Biological Science, Florida State University, Tallahassee, Florida, United States
| | - Claire E. Bardin
- Hawai'i Institute of Marine Biology, School of Ocean & Earth Sciences & Technology, University of Hawai'i at Mānoa, Moku o Lóe, Kānéohe, Hawai'i, USA
| | - Norton Chan
- Hawai'i Coral Restoration Nursery, Hawai'i Division of Aquatic Resources, Honolulu, Hawai'i, USA
| | - Chelsea Wolke
- Hawai'i Coral Restoration Nursery, Hawai'i Division of Aquatic Resources, Honolulu, Hawai'i, USA
| | - David Gulko
- Hawai'i Coral Restoration Nursery, Hawai'i Division of Aquatic Resources, Honolulu, Hawai'i, USA
| | - Robert J. Toonen
- Hawai'i Institute of Marine Biology, School of Ocean & Earth Sciences & Technology, University of Hawai'i at Mānoa, Moku o Lóe, Kānéohe, Hawai'i, USA
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Williams A, Pathmanathan JS, Stephens TG, Su X, Chiles EN, Conetta D, Putnam HM, Bhattacharya D. Multi-omic characterization of the thermal stress phenome in the stony coral Montipora capitata. PeerJ 2021; 9:e12335. [PMID: 34824906 PMCID: PMC8590396 DOI: 10.7717/peerj.12335] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 09/28/2021] [Indexed: 11/22/2022] Open
Abstract
Background Corals, which form the foundation of biodiverse reef ecosystems, are under threat from warming oceans. Reefs provide essential ecological services, including food, income from tourism, nutrient cycling, waste removal, and the absorption of wave energy to mitigate erosion. Here, we studied the coral thermal stress response using network methods to analyze transcriptomic and polar metabolomic data generated from the Hawaiian rice coral Montipora capitata. Coral nubbins were exposed to ambient or thermal stress conditions over a 5-week period, coinciding with a mass spawning event of this species. The major goal of our study was to expand the inventory of thermal stress-related genes and metabolites present in M. capitata and to study gene-metabolite interactions. These interactions provide the foundation for functional or genetic analysis of key coral genes as well as provide potentially diagnostic markers of pre-bleaching stress. A secondary goal of our study was to analyze the accumulation of sex hormones prior to and during mass spawning to understand how thermal stress may impact reproductive success in M. capitata. Methods M. capitata was exposed to thermal stress during its spawning cycle over the course of 5 weeks, during which time transcriptomic and polar metabolomic data were collected. We analyzed these data streams individually, and then integrated both data sets using MAGI (Metabolite Annotation and Gene Integration) to investigate molecular transitions and biochemical reactions. Results Our results reveal the complexity of the thermal stress phenome in M. capitata, which includes many genes involved in redox regulation, biomineralization, and reproduction. The size and number of modules in the gene co-expression networks expanded from the initial stress response to the onset of bleaching. The later stages involved the suppression of metabolite transport by the coral host, including a variety of sodium-coupled transporters and a putative ammonium transporter, possibly as a response to reduction in algal productivity. The gene-metabolite integration data suggest that thermal treatment results in the activation of animal redox stress pathways involved in quenching molecular oxygen to prevent an overabundance of reactive oxygen species. Lastly, evidence that thermal stress affects reproductive activity was provided by the downregulation of CYP-like genes and the irregular production of sex hormones during the mass spawning cycle. Overall, redox regulation and metabolite transport are key components of the coral animal thermal stress phenome. Mass spawning was highly attenuated under thermal stress, suggesting that global climate change may negatively impact reproductive behavior in this species.
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Affiliation(s)
- Amanda Williams
- Microbial Biology Graduate Program, Rutgers University, New Brunswick, United States
| | - Jananan S Pathmanathan
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, United States
| | - Timothy G Stephens
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, United States
| | - Xiaoyang Su
- Department of Medicine, Division of Endocrinology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, United States.,Metabolomics Shared Resource, Rutgers Cancer Institute of New Jersey, Rutgers University,New Brunswick, United States
| | - Eric N Chiles
- Metabolomics Shared Resource, Rutgers Cancer Institute of New Jersey, Rutgers University,New Brunswick, United States
| | - Dennis Conetta
- Department of Biological Sciences, University of Rhode Island, Kingston, United States
| | - Hollie M Putnam
- Department of Biological Sciences, University of Rhode Island, Kingston, United States
| | - Debashish Bhattacharya
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, United States
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Van Etten J, Shumaker A, Mass T, Putnam HM, Bhattacharya D. Transcriptome analysis provides a blueprint of coral egg and sperm functions. PeerJ 2020; 8:e9739. [PMID: 32874783 PMCID: PMC7441918 DOI: 10.7717/peerj.9739] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 07/26/2020] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Reproductive biology and the evolutionary constraints acting on dispersal stages are poorly understood in many stony coral species. A key piece of missing information is egg and sperm gene expression. This is critical for broadcast spawning corals, such as our model, the Hawaiian species Montipora capitata, because eggs and sperm are exposed to environmental stressors during dispersal. Furthermore, parental effects such as transcriptome investment may provide a means for cross- or trans-generational plasticity and be apparent in egg and sperm transcriptome data. METHODS Here, we analyzed M. capitata egg and sperm transcriptomic data to address three questions: (1) Which pathways and functions are actively transcribed in these gametes? (2) How does sperm and egg gene expression differ from adult tissues? (3) Does gene expression differ between these gametes? RESULTS We show that egg and sperm display surprisingly similar levels of gene expression and overlapping functional enrichment patterns. These results may reflect similar environmental constraints faced by these motile gametes. We find significant differences in differential expression of egg vs. adult and sperm vs. adult RNA-seq data, in contrast to very few examples of differential expression when comparing egg vs. sperm transcriptomes. Lastly, using gene ontology and KEGG orthology data we show that both egg and sperm have markedly repressed transcription and translation machinery compared to the adult, suggesting a dependence on parental transcripts. We speculate that cell motility and calcium ion binding genes may be involved in gamete to gamete recognition in the water column and thus, fertilization.
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Affiliation(s)
- Julia Van Etten
- Graduate Program in Ecology and Evolution, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States of America
| | - Alexander Shumaker
- Microbial Biology Graduate Program, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States of America
| | - Tali Mass
- Department of Marine Biology, University of Haifa, Haifa, Israel
| | - Hollie M. Putnam
- Department of Biological Sciences, University of Rhode Island, Kingston, RI, United States of America
| | - Debashish Bhattacharya
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States of America
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Huffmyer AS, Matsuda SB, Eggers AR, Lemus JD, Gates RD. Evaluation of laser scanning confocal microscopy as a method for characterizing reef-building coral tissue thickness and Symbiodiniaceae fluorescence. J Exp Biol 2020; 223:jeb220335. [PMID: 32098888 DOI: 10.1242/jeb.220335] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 02/13/2020] [Indexed: 08/26/2023]
Abstract
Predicting the sensitivity of reef-building corals to disturbance, including bleaching, requires an understanding of physiological responses to stressors, which may be limited by destructive sampling and the capacity of common methodologies to characterize early life history stages. We developed a new methodology using laser scanning confocal microscopy (LSCM) to measure and track the physiological condition of corals. In a thermal stress experiment, we used LSCM to track coral condition during bleaching in adults and juveniles of two species, Montipora capitata and Pocillopora acuta Depth of fluorescence in coral tissues provides a proxy measure of tissue thickness, whereas Symbiodiniaceae population fluorescence relates to both population density and chlorophyll a content. In response to thermal stress, there were significant shifts in tissue thickness and Symbiodiniaceae fluorescence with differences between life stages. This method is particularly well suited for detecting shifts in physiological condition of living corals in laboratory studies, especially in small juvenile colonies.
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Affiliation(s)
- A S Huffmyer
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, 46-007 Lilipuna Road, Kāne'ohe, HI 96744, USA
| | - S B Matsuda
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, 46-007 Lilipuna Road, Kāne'ohe, HI 96744, USA
| | - A R Eggers
- Department of Molecular and Cell Biology, University of California, Berkeley, 142 LSA #3200 Berkeley, CA 94720, USA
| | - J D Lemus
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, 46-007 Lilipuna Road, Kāne'ohe, HI 96744, USA
| | - R D Gates
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, 46-007 Lilipuna Road, Kāne'ohe, HI 96744, USA
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Schoepf V, Jury CP, Toonen RJ, McCulloch MT. Coral calcification mechanisms facilitate adaptive responses to ocean acidification. Proc Biol Sci 2018; 284:rspb.2017.2117. [PMID: 29212728 DOI: 10.1098/rspb.2017.2117] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 11/02/2017] [Indexed: 11/12/2022] Open
Abstract
Ocean acidification (OA) is a pressing threat to reef-building corals, but it remains poorly understood how coral calcification is inhibited by OA and whether corals could acclimatize and/or adapt to OA. Using a novel geochemical approach, we reconstructed the carbonate chemistry of the calcifying fluid in two coral species using both a pH and dissolved inorganic carbon (DIC) proxy (δ11B and B/Ca, respectively). To address the potential for adaptive responses, both species were collected from two sites spanning a natural gradient in seawater pH and temperature, and then subjected to three pHT levels (8.04, 7.88, 7.71) crossed by two temperatures (control, +1.5°C) for 14 weeks. Corals from the site with naturally lower seawater pH calcified faster and maintained growth better under simulated OA than corals from the higher-pH site. This ability was consistently linked to higher pH yet lower DIC values in the calcifying fluid, suggesting that these differences are the result of long-term acclimatization and/or local adaptation to naturally lower seawater pH. Nevertheless, all corals elevated both pH and DIC significantly over seawater values, even under OA. This implies that high pH upregulation combined with moderate levels of DIC upregulation promote resistance and adaptive responses of coral calcification to OA.
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Affiliation(s)
- Verena Schoepf
- ARC Centre of Excellence for Coral Reef Studies, School of Earth Sciences and UWA Oceans Institute, The University of Western Australia, Perth, Western Australia, Australia
| | - Christopher P Jury
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, USA
| | - Robert J Toonen
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, USA
| | - Malcolm T McCulloch
- ARC Centre of Excellence for Coral Reef Studies, School of Earth Sciences and UWA Oceans Institute, The University of Western Australia, Perth, Western Australia, Australia
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Frazier M, Helmkampf M, Bellinger MR, Geib SM, Takabayashi M. De novo metatranscriptome assembly and coral gene expression profile of Montipora capitata with growth anomaly. BMC Genomics 2017; 18:710. [PMID: 28893194 PMCID: PMC5594617 DOI: 10.1186/s12864-017-4090-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 08/25/2017] [Indexed: 11/10/2022] Open
Abstract
Background Scleractinian corals are a vital component of coral reef ecosystems, and of significant cultural and economic value worldwide. As anthropogenic and natural stressors are contributing to a global decline of coral reefs, understanding coral health is critical to help preserve these ecosystems. Growth anomaly (GA) is a coral disease that has significant negative impacts on coral biology, yet our understanding of its etiology and pathology is lacking. In this study we used RNA-seq along with de novo metatranscriptome assembly and homology assignment to identify coral genes that are expressed in three distinct coral tissue types: tissue from healthy corals (“healthy”), GA lesion tissue from diseased corals (“GA-affected”) and apparently healthy tissue from diseased corals (“GA-unaffected”). We conducted pairwise comparisons of gene expression among these three tissue types to identify genes and pathways that help us to unravel the molecular pathology of this coral disease. Results The quality-filtered de novo-assembled metatranscriptome contained 76,063 genes, of which 13,643 were identified as putative coral genes. Overall gene expression profiles of coral genes revealed high similarity between healthy tissue samples, in contrast to high variance among diseased samples. This indicates GA has a variety of genetic effects at the colony level, including on seemingly healthy (GA-unaffected) tissue. A total of 105 unique coral genes were found differentially expressed among tissue types. Pairwise comparisons revealed the greatest number of differentially expressed genes between healthy and GA-affected tissue (93 genes), followed by healthy and GA-unaffected tissue (33 genes), and GA-affected and -unaffected tissue (7 genes). The putative function of these genes suggests GA is associated with changes in the activity of genes involved in developmental processes and activation of the immune system. Conclusion This is one of the first transcriptome-level studies to investigate coral GA, and the first metatranscriptome assembly for the M. capitata holobiont. The gene expression data, metatranscriptome assembly and methodology developed through this study represent a significant addition to the molecular information available to further our understanding of this coral disease. Electronic supplementary material The online version of this article (10.1186/s12864-017-4090-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Monika Frazier
- Tropical Conservation Biology and Environmental Science, University of Hawai'i at Hilo, 200 West Kāwili Street, Hilo, HI, 96720, USA
| | - Martin Helmkampf
- Tropical Conservation Biology and Environmental Science, University of Hawai'i at Hilo, 200 West Kāwili Street, Hilo, HI, 96720, USA
| | - M Renee Bellinger
- Tropical Conservation Biology and Environmental Science, University of Hawai'i at Hilo, 200 West Kāwili Street, Hilo, HI, 96720, USA
| | - Scott M Geib
- United States Department of Agriculture, Agriculture Research Service, Daniel K Inouye U.S. Pacific Basin Agricultural Research Center, 64 Nowelo St, Hilo, HI, 96720, USA
| | - Misaki Takabayashi
- Tropical Conservation Biology and Environmental Science, University of Hawai'i at Hilo, 200 West Kāwili Street, Hilo, HI, 96720, USA. .,Marine Science Department, University of Hawai'i at Hilo, 200 West Kāwili Street, Hilo, HI, 96720, USA.
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Beurmann S, Runyon CM, Videau P, Callahan SM, Aeby GS. Assessment of disease lesion removal as a method to control chronic Montipora white syndrome. Dis Aquat Organ 2017; 123:173-179. [PMID: 28262637 DOI: 10.3354/dao03088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Coral colonies in Kāne'ohe Bay, Hawai'i (USA), are afflicted with the tissue loss disease chronic Montipora white syndrome (cMWS). Here we show that removal of chronic disease lesions is a potential method to slow the progression of cMWS in M. capitata. Over the 24 wk observation period, treatment colonies lost almost half the amount of tissue that was lost by control colonies. The percentage of tissue loss at each sampling interval (mean ± SEM; treatment: 1.17 ± 0.47%, control: 2.25 ± 0.63%) and the rate of tissue loss per day (treatment: 0.13 ± 0.04%, control: 0.27 ± 0.08%) were both significantly lower on treated colonies than control colonies. While lesion removal stopped tissue loss at the initial infection site, which allowed colony healing, it did not prevent re-infection; in all but one of the treated colonies, new cMWS lesions appeared in other areas of the colony but not around the treatment margins. Additionally, the rate of new infections was similar between treatment and control colonies, indicating that physical injury from lesion removal did not appear to increase cMWS susceptibility. These results indicate that lesion removal reduced morbidity in M. capitata exhibiting cMWS but did not stop the disease.
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Affiliation(s)
- Silvia Beurmann
- University of Hawai'i at Manoa, Department of Microbiology, Honolulu, HI 96822, USA
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Abstract
On Hawaiian reefs, the fast-growing, invasive algae Gracilaria salicornia overgrows coral heads, restricting water flow and light, thereby smothering corals. Field data shows hypoxic conditions (dissolved oxygen (DO2) < 2 mg/L) occurring underneath algal mats at night, and concurrent bleaching and partial tissue loss of shaded corals. To analyze the impact of nighttime oxygen-deprivation on coral health, this study evaluated changes in coral metabolism through the exposure of corals to chronic hypoxic conditions and subsequent analyses of lactate, octopine, alanopine, and strombine dehydrogenase activities, critical enzymes employed through anaerobic respiration. Following treatments, lactate and octopine dehydrogenase activities were found to have no significant response in activities with treatment and time. However, corals subjected to chronic nighttime hypoxia were found to exhibit significant increases in alanopine dehydrogenase activity after three days of exposure and strombine dehydrogenase activity starting after one overnight exposure cycle. These findings provide new insights into coral metabolic shifts in extremely low-oxygen environments and point to ADH and SDH assays as tools for quantifying the impact of hypoxia on coral health.
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Affiliation(s)
- James W A Murphy
- Kewalo Marine Laboratory, Pacific Biosciences Research Center, University of Hawaii at Manoa , Honolulu, HI , United States
| | - Robert H Richmond
- Kewalo Marine Laboratory, Pacific Biosciences Research Center, University of Hawaii at Manoa , Honolulu, HI , United States
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10
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Work TM, Farah Y. Lectins stain cells differentially in the coral, Montipora capitata. J Invertebr Pathol 2014; 117:42-50. [PMID: 24518620 DOI: 10.1016/j.jip.2014.01.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2013] [Revised: 01/20/2014] [Accepted: 01/31/2014] [Indexed: 11/18/2022]
Abstract
A limitation in our understanding of coral disease pathology and cellular pathogenesis is a lack of reagents to characterize coral cells. We evaluated the utility of plant lectins to stain tissues of a dominant coral, Montipora capitata, from Hawaii. Of 22 lectins evaluated, nine of these stained structures in the upper or basal body wall of corals. Specific structures revealed by lectins that were not considered distinct or evident on routine hematoxylin and eosin sections of coral tissues included apical and basal granules in gastrodermis and epidermis, cnidoglandular tract and actinopharynx cell surface membranes, capsules of mature holotrichous isorhizas, and perivitelline and periseminal cells. Plant lectins could prove useful to further our understanding of coral physiology, anatomy, cell biology, and disease pathogenesis.
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Affiliation(s)
- Thierry M Work
- U.S. Geological Survey, National Wildlife Health Center, Honolulu Field Station, PO Box 50167, Honolulu, HI 96850, USA.
| | - Yael Farah
- University of Illinois, School of Veterinary Medicine, Urbana Champaign, IL 61820, USA
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