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Toledo-Rodriguez DA, Veglia A, Jimenez Marrero NM, Gomez-Samot JM, McFadden CS, Weil E, Schizas NV. Shadows over Caribbean reefs: Identification of a new invasive soft coral species, Xenia umbellata, in southwest Puerto Rico. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.07.592775. [PMID: 38766101 PMCID: PMC11100662 DOI: 10.1101/2024.05.07.592775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
In October 2023, several colonies of an alien soft coral species were reported on shallow reefs in southwest Puerto Rico. The soft coral was identified as a xeniid octocoral (species undetermined), resembling the octocoral Unomia stolonifera, which has invaded and overgrown reefs in Venezuela in recent years. To conclusively characterize the species of the invading xeniid, we employed multilocus barcoding targeting four genes (ND2, mtMutS, COI, and 28S) of three separate colonies across three locations in southwest Puerto Rico. Sequence comparisons with xeniid sequences from GenBank, including those from the genera Xenia and Unomia, indicated a 100% sequence identity (>3,000 bp combined) with the species Xenia umbellata (Octocorallia : Malacalcyonacea : Xeniidae). Xenia umbellata is native to the Red Sea and to our knowledge, this represents the first confirmed case of this species as an invader on Caribbean reefs. Similar to U. stolonifera, X. umbellata is well known for its ability to rapidly overgrow substrate as well as tolerate environmental extremes. In addition, X. umbellata has recently been proposed as a model system for tissue regeneration having the ability to regenerate completely from a single tentacle. These characteristics greatly amplify X. umbellata's potential to adversely affect any reef it invades. Our findings necessitate continued collaborative action between local management agencies and stakeholders in Puerto Rico, as well as neighboring islands, to monitor and control this invasion prior to significant ecological perturbation.
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Affiliation(s)
- Daniel A. Toledo-Rodriguez
- Department of Marine Sciences, University of Puerto Rico at Mayagüez, PO Box 9000, Mayagüez, PR 00681, USA
- EcoAzul, HC01 Box 4729, Lajas, PR 00667, USA
| | - Alex Veglia
- EcoAzul, HC01 Box 4729, Lajas, PR 00667, USA
- Department of Biology, University of Puerto Rico at Mayagüez, PO Box 9000, Mayagüez, PR 00681, USA
| | - Nilda M. Jimenez Marrero
- Department of Natural and Environmental Resources, San José Industrial Park, 1375 Ave. Ponce de León, San Juan, PR 00926, USA
| | - Joyce M. Gomez-Samot
- Department of Marine Sciences, University of Puerto Rico at Mayagüez, PO Box 9000, Mayagüez, PR 00681, USA
| | | | - Ernesto Weil
- Department of Marine Sciences, University of Puerto Rico at Mayagüez, PO Box 9000, Mayagüez, PR 00681, USA
| | - Nikolaos V. Schizas
- Department of Marine Sciences, University of Puerto Rico at Mayagüez, PO Box 9000, Mayagüez, PR 00681, USA
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Dellisanti W, Zhang Q, Ferrier-Pagès C, Kühl M. Contrasting effects of increasing dissolved iron on photosynthesis and O 2 availability in the gastric cavity of two Mediterranean corals. PeerJ 2024; 12:e17259. [PMID: 38699194 PMCID: PMC11064864 DOI: 10.7717/peerj.17259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 03/27/2024] [Indexed: 05/05/2024] Open
Abstract
Iron (Fe) plays a fundamental role in coral symbiosis, supporting photosynthesis, respiration, and many important enzymatic reactions. However, the extent to which corals are limited by Fe and their metabolic responses to inorganic Fe enrichment remains to be understood. We used respirometry, variable chlorophyll fluorescence, and O2 microsensors to investigate the impact of increasing Fe(III) concentrations (20, 50, and 100 nM) on the photosynthetic capacity of two Mediterranean coral species, Cladocora caespitosa and Oculina patagonica. While the bioavailability of inorganic Fe can rapidly decrease, we nevertheless observed significant physiological effects at all Fe concentrations. In C. caespitosa, exposure to 50 nM Fe(III) increased rates of respiration and photosynthesis, while the relative electron transport rate (rETR(II)) decreased at higher Fe(III) exposure (100 nM). In contrast, O. patagonica reduced respiration, photosynthesis rates, and maximum PSII quantum yield (Fv/Fm) across all iron enrichments. Both corals exhibited increased hypoxia (<50 µmol O2 L-1) within their gastric cavity at night when exposed to 50 and 100 nM Fe(III), leading to increased polyp contraction time and reduced O2 exchange with the surrounding water. Our results indicate that C. caespitosa, but not O. patagonica, might be limited in Fe for achieving maximal photosynthetic efficiency. Understanding the multifaceted role of iron in corals' health and their response to environmental change is crucial for effective coral conservation.
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Affiliation(s)
- Walter Dellisanti
- Department of Biology, Marine Biology Section, University of Copenhagen, Helsingør, Denmark
| | - Qingfeng Zhang
- Department of Biology, Marine Biology Section, University of Copenhagen, Helsingør, Denmark
| | - Christine Ferrier-Pagès
- Coral Ecophysiology Laboratory, Center Scientifique de Monaco, Principality of Monaco, Monaco
| | - Michael Kühl
- Department of Biology, Marine Biology Section, University of Copenhagen, Helsingør, Denmark
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Ma Q, Pang M, Huang Z, Mu R, Pang Y. Derivation and application of a parameter for denitrification rates in the Taihu Lake model based on an isotope-labeled denitrification experiment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:15559-15570. [PMID: 38296932 DOI: 10.1007/s11356-024-32227-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 01/24/2024] [Indexed: 02/02/2024]
Abstract
In recent years, the total nitrogen concentration in Taihu Lake has decreased significantly. Denitrification, as the main nitrogen removal process, is the key reason for the decrease. Here, the denitrification parameter values in the Environmental Fluid Dynamic Code (EFDC) model were calculated based on isotope-labeled denitrification experiment instead of selecting the recommended values directly. This study further focused on EFDC denitrification parameter derivation with an experimental denitrification rate (Dtot) to reduce simulation errors. According to the EFDC nitrate deposition flux mechanism, the conversion equation between the denitrification rate of the first sediment layer ([Formula: see text]) in EFDC and Dtot was successfully derived. The results revealed a linear correlation between [Formula: see text] and (Dtot)1/2. The [Formula: see text] values of sampling points ranged from 0.25 to 0.27 m·day-1, within the range of model parameters. After substituting [Formula: see text] into the Taihu Lake EFDC model, the average percentage bias and determination coefficient of total nitrogen were 16.25% and 0.87, respectively. The average total nitrogen concentration reduction caused by denitrification at water quality calibration points ranged from 0.027 to 0.305 mg·L-1.
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Affiliation(s)
- Qiuxia Ma
- College of Environment, Hohai University, Nanjing, 210098, China
| | - Min Pang
- College of Hydrology and Water Resources, Hohai University, Nanjing, 210098, China.
| | - Zhilin Huang
- Guangdong Research Institute of Water Resources and Hydropower, Guangzhou, 510610, China
| | - Ronghua Mu
- East China Inspection Bureau, Ministry of Ecology and Environment, Nanjing, 210019, China
| | - Yong Pang
- College of Environment, Hohai University, Nanjing, 210098, China
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Tilstra A, Braxator L, Thobor B, Mezger SD, Hill CEL, El-Khaled YC, Caporale G, Kim S, Wild C. Short-term ocean acidification decreases pulsation and growth of the widespread soft coral Xenia umbellata. PLoS One 2023; 18:e0294470. [PMID: 37967066 PMCID: PMC10651030 DOI: 10.1371/journal.pone.0294470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 10/31/2023] [Indexed: 11/17/2023] Open
Abstract
Coral reefs may experience lower pH values as a result of ocean acidification (OA), which has negative consequences, particularly for calcifying organisms. Thus far, the effects of this global factor have been mainly investigated on hard corals, while the effects on soft corals remain relatively understudied. We therefore carried out a manipulative aquarium experiment for 21 days to study the response of the widespread pulsating soft coral Xenia umbellata to simulated OA conditions. We gradually decreased the pH from ambient (~8.3) to three consecutive 7-day long pH treatments of 8.0, 7.8, and 7.6, using a CO2 dosing system. Monitored response variables included pulsation rate, specific growth rate, visual coloration, survival, Symbiodiniaceae cell densities and chlorophyll a content, photosynthesis and respiration, and finally stable isotopes of carbon (C) and nitrogen (N) as well as CN content. Pulsation decreased compared to controls with each consecutive lowering of the pH, i.e., 17% at pH 8.0, 26% at pH 7.8 and 32% at pH 7.6, accompanied by an initial decrease in growth rates of ~60% at pH 8.0, not decreasing further at lower pH. An 8.3 ‰ decrease of δ13C confirmed that OA exposed colonies had a higher uptake and availability of atmospheric CO2. Coral productivity, i.e., photosynthesis, was not affected by higher dissolved inorganic C availability and none of the remaining response variables showed any significant differences. Our findings suggest that pulsation is a phenotypically plastic mechanism for X. umbellata to adjust to different pH values, resulting in reduced growth rates only, while maintaining high productivity. Consequently, pulsation may allow X. umbellata to inhabit a broad pH range with minimal effects on its overall health. This resilience may contribute to the competitive advantage that soft corals, particularly X. umbellata, have over hard corals.
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Affiliation(s)
- Arjen Tilstra
- Department of Marine Ecology, University of Bremen, Bremen, Germany
| | - Lorena Braxator
- Department of Marine Ecology, University of Bremen, Bremen, Germany
| | - Bianca Thobor
- Department of Marine Ecology, University of Bremen, Bremen, Germany
| | - Selma D. Mezger
- Department of Marine Ecology, University of Bremen, Bremen, Germany
| | | | | | - Giulia Caporale
- Department of Marine Ecology, University of Bremen, Bremen, Germany
| | - Sohyoung Kim
- Department of Marine Ecology, University of Bremen, Bremen, Germany
| | - Christian Wild
- Department of Marine Ecology, University of Bremen, Bremen, Germany
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Hill CEL, Abbass SG, Caporale G, El‐Khaled YC, Kuhn L, Schlenzig T, Wild C, Tilstra A. Physiology of the widespread pulsating soft coral Xenia umbellata is affected by food sources, but not by water flow. Ecol Evol 2023; 13:e10483. [PMID: 37664515 PMCID: PMC10472534 DOI: 10.1002/ece3.10483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 08/01/2023] [Accepted: 08/08/2023] [Indexed: 09/05/2023] Open
Abstract
Coral energy and nutrient acquisition strategies are complex and sensitive to environmental conditions such as water flow. While high water flow can enhance feeding in hard corals, knowledge about the effects of water flow on the feeding of soft corals, particularly those pulsating, is still limited. In this study, we thus investigated the effects of feeding and water flow on the physiology of the pulsating soft coral Xenia umbellata. We crossed three feeding treatments: (i) no feeding, (ii) particulate organic matter (POM) in the form of phytoplankton and (iii) dissolved organic carbon (DOC) in the form of glucose, with four water volume exchange rates (200, 350, 500 and 650 L h-1) over 15 days. Various ecophysiological parameters were assessed including pulsation rate, growth rate, isotopic and elemental ratios of carbon (C) and nitrogen (N) as well as photo-physiological parameters of the Symbiodiniaceae (cell density, chlorophyll-a and mitotic index). Water flow had no significant effect but feeding had a substantial impact on the physiology of the X. umbellata holobiont. In the absence of food, corals exhibited significantly lower pulsation rates, lower Symbiodiniaceae cell density and lower mitotic indices compared to the fed treatments, yet significantly higher chlorophyll-a per cell and total N content. Differences were also observed between the two feeding treatments, with significantly higher pulsation rates and lower chlorophyll-a per cell in the DOC treatment, but higher C and N content in the POM treatment. Our findings suggest that the X. umbellata holobiont can be viable under different trophic strategies, though favouring mixotrophy. Additionally, the physiology of the X. umbellata may be regulated through its own pulsating behaviour without any positive or negative effects from different water flow. Therefore, this study contributes to our understanding of soft coral ecology, particularly regarding the competitive success and widespread distribution of X. umbellata.
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Affiliation(s)
- C. E. L. Hill
- Marine Ecology Department, Faculty of Biology and ChemistryUniversity of BremenBremenGermany
| | - S. G. Abbass
- Marine Ecology Department, Faculty of Biology and ChemistryUniversity of BremenBremenGermany
- Marine Science Department, Faculty of SciencePort Said UniversityPort SaidEgypt
| | - G. Caporale
- Marine Ecology Department, Faculty of Biology and ChemistryUniversity of BremenBremenGermany
| | - Y. C. El‐Khaled
- Marine Ecology Department, Faculty of Biology and ChemistryUniversity of BremenBremenGermany
- Red Sea Research Center, Biological and Environmental Science and Engineering DivisionKing Abdullah University of Science and TechnologyJeddahSaudi Arabia
| | - L. Kuhn
- Marine Ecology Department, Faculty of Biology and ChemistryUniversity of BremenBremenGermany
| | - T. Schlenzig
- Marine Ecology Department, Faculty of Biology and ChemistryUniversity of BremenBremenGermany
| | - C. Wild
- Marine Ecology Department, Faculty of Biology and ChemistryUniversity of BremenBremenGermany
| | - A. Tilstra
- Marine Ecology Department, Faculty of Biology and ChemistryUniversity of BremenBremenGermany
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Mezger SD, Klinke A, Tilstra A, El-Khaled YC, Thobor B, Wild C. The widely distributed soft coral Xenia umbellata exhibits high resistance against phosphate enrichment and temperature increase. Sci Rep 2022; 12:22135. [PMID: 36550166 PMCID: PMC9780247 DOI: 10.1038/s41598-022-26325-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022] Open
Abstract
Both global and local factors affect coral reefs worldwide, sometimes simultaneously. An interplay of these factors can lead to phase shifts from hard coral dominance to algae or other invertebrates, particularly soft corals. However, most studies have targeted the effects of single factors, leaving pronounced knowledge gaps regarding the effects of combined factors on soft corals. Here, we investigated the single and combined effects of phosphate enrichment (1, 2, and 8 μM) and seawater temperature increase (26 to 32 °C) on the soft coral Xenia umbellata by quantifying oxygen fluxes, protein content, and stable isotope signatures in a 5-week laboratory experiment. Findings revealed no significant effects of temperature increase, phosphate enrichment, and the combination of both factors on oxygen fluxes. However, regardless of the phosphate treatment, total protein content and carbon stable isotope ratios decreased significantly by 62% and 7% under temperature increase, respectively, suggesting an increased assimilation of their energy reserves. Therefore, we hypothesize that heterotrophic feeding may be important for X. umbellata to sustain their energy reserves under temperature increase, highlighting the advantages of a mixotrophic strategy. Overall, X. umbellata shows a high tolerance towards changes in global and local factors, which may explain their competitive advantage observed at many Indo-Pacific reef locations.
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Affiliation(s)
- Selma D. Mezger
- grid.7704.40000 0001 2297 4381Department of Marine Ecology, Faculty of Biology and Chemistry, University of Bremen, Leobener Str. 6, 28359 Bremen, Germany
| | - Annabell Klinke
- grid.7704.40000 0001 2297 4381Department of Marine Ecology, Faculty of Biology and Chemistry, University of Bremen, Leobener Str. 6, 28359 Bremen, Germany ,grid.461729.f0000 0001 0215 3324Leibniz Centre for Tropical Marine Research, Fahrenheitstraße 6, 28359 Bremen, Germany
| | - Arjen Tilstra
- grid.7704.40000 0001 2297 4381Department of Marine Ecology, Faculty of Biology and Chemistry, University of Bremen, Leobener Str. 6, 28359 Bremen, Germany
| | - Yusuf C. El-Khaled
- grid.7704.40000 0001 2297 4381Department of Marine Ecology, Faculty of Biology and Chemistry, University of Bremen, Leobener Str. 6, 28359 Bremen, Germany
| | - Bianca Thobor
- grid.7704.40000 0001 2297 4381Department of Marine Ecology, Faculty of Biology and Chemistry, University of Bremen, Leobener Str. 6, 28359 Bremen, Germany
| | - Christian Wild
- grid.7704.40000 0001 2297 4381Department of Marine Ecology, Faculty of Biology and Chemistry, University of Bremen, Leobener Str. 6, 28359 Bremen, Germany
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