1
|
Piller WE, Harzhauser M. Bryoherms from the lower Sarmatian (upper Serravallian, Middle Miocene) of the Central Paratethys. FACIES 2023; 69:5. [PMID: 36876224 PMCID: PMC9974694 DOI: 10.1007/s10347-023-00661-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 02/03/2023] [Indexed: 06/18/2023]
Abstract
Bryozoan-serpulid-algal-thrombolite bioherms of up to 50 cm size are described from the Sarmatian (upper Middle Miocene) of the Central Paratethys. They occur on top of lower Sarmatian carbonate sediments of high-energy conditions and the individual bioherms settle on crests of ripples. The buildups are overlain and partly truncated by cross-bedded oolites of late Sarmatian age. Buildup growth starts with a Cryptosula/Hydroides (bryozoan/serpulid) pioneer community, followed by nodular Schizoporella (bryozoan) colonies overgrown by coralline algae/microbial mats and a thrombolite with calcareous algal filaments. All these constituents form a framestone fabric which is overall dominated by bryozoans labeling them as bryoherms. Inside the bioherms ecological successions of higher frequencies occur which are interpreted to reflect short-time environmental fluctuations such as nutrient availability, oxygenation (possible anoxia), salinity (possible brackish water), temperature and water level. The internal succession in individual bioherms is related to long-term environmental changes including general shallowing, increasing nutrient supply and decreasing water circulation and oxygenation. The described bioherms are most similar to modern bryostromatolites of the Coorong lagoon in S Australia and also similar to structures in the Netherlands. The widespread occurrence of bryoherms/bryostromatolites in the Central Paratethys suggests a phase of considerable eutrophication during the early Sarmatian.
Collapse
Affiliation(s)
- Werner E. Piller
- Institut für Erdwissenschaften, NAWI Graz Geocenter, Universität Graz, Heinrichstraße 26, 8010 Graz, Austria
| | - Mathias Harzhauser
- Geologisch-Paläontologische Abteilung, Naturhistorisches Museum Wien, Burgring 7, 1014 Vienna, Austria
| |
Collapse
|
2
|
Oliva M, Mennillo E, Barbaglia M, Monni G, Tardelli F, Casu V, Pretti C. The serpulid Ficopomatus enigmaticus () as candidate organisms for ecotoxicological assays in brackish and marine waters. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 148:1096-1103. [PMID: 26598046 DOI: 10.1016/j.ecoenv.2015.10.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 10/07/2015] [Accepted: 10/08/2015] [Indexed: 06/05/2023]
Abstract
Ficopomatus enigmaticus is an ubiquitous fouling reef-forming species, easy to sample and recognize, diecious with gamete spawning along different seasons in different salinity conditions. Due to its characteristics it could become a good candidate for the monitoring of both marine and brackish waters. The suitability of F. enigmaticus as a promising model organism in ecotoxicological bioassays was evaluated by a sperm toxicity and a larval development assay. The fertilization rate in different salinity conditions (range 5-35‰) was first assessed in order to detect the salinity threshold within which profitably perform the assays. Afterward copper (Cu2+), cadmium (Cd2+), sodium dodecyl sulfate (SDS) and 4-n-nonylphenol (NP) were used as reference toxicants in exposure experiments with spermatozoids (sperm toxicity assay) and zygotes (larval development assay). A dose-response effect was obtained for all tested toxicants along all salinity conditions except for 5‰ salinity condition where a too low (<30%) fertilization rate was observed. NP showed the highest degree of toxicity both in sperm toxicity and larval development assay. In some cases the results, expressed as EC50 values at 35‰ salinity condition, were similar to those observed in the literature for marine organisms such as the sea urchin (Paracentrotus lividus) and the marine serpulid Hydroides elegans, while the exposure of F. enigmaticus spermatozoids' to Cd2+ and NP resulted in toxicity effects several orders of magnitude higher than observed in P. lividus. Spermatozoids resulted to be slightly more sensitive then zygotes to all different toxicants.
Collapse
Affiliation(s)
- Matteo Oliva
- Department of Veterinary Sciences, University of Pisa, Italy; Interuniversitary Consortium of Marine Biology of Leghorn "G. Bacci", Italy
| | - Elvira Mennillo
- Department of Veterinary Sciences, University of Pisa, Italy
| | | | | | | | - Valentina Casu
- Department of Veterinary Sciences, University of Pisa, Italy
| | - Carlo Pretti
- Department of Veterinary Sciences, University of Pisa, Italy; Interuniversitary Consortium of Marine Biology of Leghorn "G. Bacci", Italy.
| |
Collapse
|
3
|
Foo SA, Byrne M. Marine gametes in a changing ocean: Impacts of climate change stressors on fecundity and the egg. MARINE ENVIRONMENTAL RESEARCH 2017; 128:12-24. [PMID: 28237403 DOI: 10.1016/j.marenvres.2017.02.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Revised: 02/10/2017] [Accepted: 02/13/2017] [Indexed: 06/06/2023]
Abstract
In marine invertebrates, the environmental history of the mother can influence fecundity and egg size. Acclimation of females in climate change stressors, increased temperature and low pH, results in a decrease in egg number and size in many taxa, with the exception of cephalopods, where eggs increase in size. With respect to spawned eggs, near future levels of ocean acidification can interfere with the egg's block to polyspermy and intracellular pH. Reduction of the extracellular egg jelly coat seen in low pH conditions has implications for impaired egg function and fertilization. Some fast generation species (e.g. copepods, polychaetes) have shown restoration of female reproductive output after several generations in treatments. It will be important to determine if the changes to egg number and size induced by exposure to climate change stressors are heritable.
Collapse
Affiliation(s)
- Shawna A Foo
- School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia.
| | - Maria Byrne
- Schools of Medical and Biological Sciences, The University of Sydney, Sydney, New South Wales, Australia
| |
Collapse
|
4
|
Li C, Meng Y, He C, Chan VBS, Yao H, Thiyagarajan V. Mechanical robustness of the calcareous tubeworm Hydroides elegans: warming mitigates the adverse effects of ocean acidification. BIOFOULING 2016; 32:191-204. [PMID: 26820060 DOI: 10.1080/08927014.2015.1129532] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 12/01/2015] [Indexed: 06/05/2023]
Abstract
Development of antifouling strategies requires knowledge of how fouling organisms would respond to climate change associated environmental stressors. Here, a calcareous tube built by the tubeworm, Hydroides elegans, was used as an example to evaluate the individual and interactive effects of ocean acidification (OA), warming and reduced salinity on the mechanical properties of a tube. Tubeworms produce a mechanically weaker tube with less resistance to simulated predator attack under OA (pH 7.8). Warming (29°C) increased tube volume, tube mineral density and the tube's resistance to a simulated predatory attack. A weakening effect by OA did not make the removal of tubeworms easier except for the earliest stage, in which warming had the least effect. Reduced salinity (27 psu) did not affect tubes. This study showed that both mechanical analysis and computational modeling can be integrated with biofouling research to provide insights into how fouling communities might develop in future ocean conditions.
Collapse
Affiliation(s)
- Chaoyi Li
- a The Swire Institute of Marine Sciences and School of Biological Sciences , The University of Hong Kong , Hong Kong SAR , China
| | - Yuan Meng
- a The Swire Institute of Marine Sciences and School of Biological Sciences , The University of Hong Kong , Hong Kong SAR , China
| | - Chong He
- b Department of Mechanical Engineering , The Hong Kong Polytechnic University , Hong Kong SAR , China
| | - Vera B S Chan
- c Department of Biological Sciences , University of Clemson , Clemson , SC , USA
| | - Haimin Yao
- b Department of Mechanical Engineering , The Hong Kong Polytechnic University , Hong Kong SAR , China
| | - V Thiyagarajan
- a The Swire Institute of Marine Sciences and School of Biological Sciences , The University of Hong Kong , Hong Kong SAR , China
| |
Collapse
|
5
|
Lane A, Campanati C, Dupont S, Thiyagarajan V. Trans-generational responses to low pH depend on parental gender in a calcifying tubeworm. Sci Rep 2015; 5:10847. [PMID: 26039184 PMCID: PMC4454138 DOI: 10.1038/srep10847] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 04/24/2015] [Indexed: 11/25/2022] Open
Abstract
The uptake of anthropogenic CO2 emissions by oceans has started decreasing pH and carbonate ion concentrations of seawater, a process called ocean acidification (OA). Occurring over centuries and many generations, evolutionary adaptation and epigenetic transfer will change species responses to OA over time. Trans-generational responses, via genetic selection or trans-generational phenotypic plasticity, differ depending on species and exposure time as well as differences between individuals such as gender. Males and females differ in reproductive investment and egg producing females may have less energy available for OA stress responses. By crossing eggs and sperm from the calcareous tubeworm Hydroides elegans (Haswell, 1883) raised in ambient (8.1) and low (7.8) pH environments, we observed that paternal and maternal low pH experience had opposite and additive effects on offspring. For example, when compared to offspring with both parents from ambient pH, growth rates of offspring of fathers or mothers raised in low pH were higher or lower respectively, but there was no difference when both parents were from low pH. Gender differences may result in different selection pressures for each gender. This may result in overestimates of species tolerance and missed opportunities of potentially insightful comparisons between individuals of the same species.
Collapse
Affiliation(s)
- Ackley Lane
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong SAR
| | - Camilla Campanati
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong SAR
| | - Sam Dupont
- Department of Biological and Environmental Sciences, The Sven Lovén Centre for Marine Sciences - Kristineberg, University of Gothenburg, Fiskebäckskil, Sweden
| | - Vengatesen Thiyagarajan
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong SAR
| |
Collapse
|
6
|
Evidence of compositional and ultrastructural shifts during the development of calcareous tubes in the biofouling tubeworm, Hydroides elegans. J Struct Biol 2015; 189:230-7. [PMID: 25600412 DOI: 10.1016/j.jsb.2015.01.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 01/08/2015] [Accepted: 01/09/2015] [Indexed: 11/22/2022]
Abstract
The serpulid tubeworm, Hydroides elegans, is an ecologically and economically important species whose biology has been fairly well studied, especially in the context of larval development and settlement on man-made objects (biofouling). Nevertheless, ontogenetic changes associated with calcareous tube composition and structures have not yet been studied. Here, the ultrastructure and composition of the calcareous tubes built by H. elegans was examined in the three early calcifying juvenile stages and in the adult using XRD, FTIR, ICP-OES, SEM and Raman spectroscopy. Ontogenetic shifts in carbonate mineralogy were observed, for example, juvenile tubes contained more amorphous calcium carbonate and were predominantly aragonitic whereas adult tubes were bimineralic with considerably more calcite. The mineral composition gradually shifted during the tube development as shown by a decrease in Sr/Ca and an increase of Mg/Ca ratios with the tubeworm's age. The inner tube layer contained calcite, whereas the outer layer contained aragonite. Similarly, the tube complexity in terms of ultrastructure was associated with development. The sequential appearance of unoriented ultrastructures followed by oriented ultrastructures may reflect the evolutionary history of serpulid tube biominerals. As aragonitic structures are more susceptible to dissolution under ocean acidification (OA) conditions but are more difficult to be removed by anti-fouling treatments, the early developmental stages of the tubeworms may be vulnerable to OA but act as the important target for biofouling control.
Collapse
|
7
|
Li C, Chan VBS, He C, Meng Y, Yao H, Shih K, Thiyagarajan V. Weakening mechanisms of the serpulid tube in a high-CO2 world. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:14158-14167. [PMID: 25415324 DOI: 10.1021/es501638h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Many benthic marine organisms produce calcium carbonate (CaCO3) structures for mechanical protection through a biologically controlled calcification process. However, the oceans are becoming unfavorable for calcification because of the stress associated with ocean acidification (OA) and associated chemical changes such as declining saturation state of CaCO3 and decreasing seawater pH. This work studies the impacts of OA-driven decreased pH on the calcareous tubes produced by the serpulid tubeworm Hydroides elegans. Tubes grown under control and OA experimental conditions were measured for structural and mechanical properties, and their mechanical properties were further interpreted using finite element analysis (FEA). The near-future predicted pH value of 7.8 altered tube ultrastructure, volume, and density and decreased the mean tube hardness and elasticity by ∼ 80 and ∼ 70%, respectively. The crushing force required for breaking the tube was reduced by 64%. The FEA results demonstrated how a simulated predator attack may affect the structure with different structural and mechanical properties and consequently shift the stress development and distribution in the tubes, causing a more concentrated stress distribution and therefore leading to a lower ability to withstand attacks.
Collapse
Affiliation(s)
- Chaoyi Li
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong , Pokfulam, Hong Kong SAR
| | | | | | | | | | | | | |
Collapse
|
8
|
Mukherjee J, Wong KKW, Chandramouli KH, Qian PY, Leung PTY, Wu RSS, Thiyagarajan V. Proteomic response of marine invertebrate larvae to ocean acidification and hypoxia during metamorphosis and calcification. J Exp Biol 2013; 216:4580-9. [DOI: 10.1242/jeb.094516] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
SUMMARY
Calcifying marine invertebrates with complex life cycles are particularly at risk to climate changes as they undergo an abrupt ontogenetic shift during larval metamorphosis. Although our understanding of the larval response to climate changes is rapidly advancing, the proteome plasticity involved in a compensatory response to climate change is still unknown. In this study, we investigated the proteomic response of metamorphosing larvae of the tubeworm Hydroides elegans, challenged with two climate change stressors, ocean acidification (OA; pH 7.6) and hypoxia (HYP; 2.8 mg O2 l−1), and with both combined. Using a two-dimensional gel electrophoresis (2-DE)-based approach coupled with mass spectrometry, we found that climate change stressors did not affect metamorphosis except under OA, but altered the larval proteome and phosphorylation status. Metabolism and various stress and calcification-related proteins were downregulated in response to OA. In OA and HYP combined, HYP restored the expression of the calcification-related proteins to the control levels. We speculate that mild HYP stress could compensate for the negative effects of OA. This study also discusses the potential functions of selected proteins that might play important roles in larval acclimation and adaption to climate change.
Collapse
Affiliation(s)
- Joy Mukherjee
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong SAR
| | - Kelvin K. W. Wong
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong SAR
| | | | - Pei-Yuan Qian
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR
| | - Priscilla T. Y. Leung
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong SAR
| | - Rudolf S. S. Wu
- Centre for Marine Environmental Research and Innovative Technology, School of Biological Science, The University of Hong Kong, Hong Kong SAR
| | - Vengatesen Thiyagarajan
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong SAR
| |
Collapse
|
9
|
Jensen N, Allen RM, Marshall DJ. Adaptive maternal and paternal effects: gamete plasticity in response to parental stress. Funct Ecol 2013. [DOI: 10.1111/1365-2435.12195] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Natasha Jensen
- School of Biological Sciences University of Queensland Brisbane Queensland 4072 Australia
| | - Richard M. Allen
- Department of Oceanography Dalhousie University Halifax Nova Scotia B3H 4R2 Canada
- Department of Ocean Sciences Memorial University St. John's Newfoundland A1C 5S7 Canada
| | - Dustin J. Marshall
- School of Biological Sciences Monash University Melbourne Victoria 3800 Australia
| |
Collapse
|
10
|
Chan VBS, Thiyagarajan V, Lu XW, Zhang T, Shih K. Temperature dependent effects of elevated CO2 on shell composition and mechanical properties of Hydroides elegans: insights from a multiple stressor experiment. PLoS One 2013; 8:e78945. [PMID: 24265732 PMCID: PMC3827122 DOI: 10.1371/journal.pone.0078945] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 09/16/2013] [Indexed: 11/23/2022] Open
Abstract
The majority of marine benthic invertebrates protect themselves from predators by producing calcareous tubes or shells that have remarkable mechanical strength. An elevation of CO2 or a decrease in pH in the environment can reduce intracellular pH at the site of calcification and thus interfere with animal’s ability to accrete CaCO3. In nature, decreased pH in combination with stressors associated with climate change may result in the animal producing severely damaged and mechanically weak tubes. This study investigated how the interaction of environmental drivers affects production of calcareous tubes by the serpulid tubeworm, Hydroides elegans. In a factorial manipulative experiment, we analyzed the effects of pH (8.1 and 7.8), salinity (34 and 27‰), and temperature (23°C and 29°C) on the biomineral composition, ultrastructure and mechanical properties of the tubes. At an elevated temperature of 29°C, the tube calcite/aragonite ratio and Mg/Ca ratio were both increased, the Sr/Ca ratio was decreased, and the amorphous CaCO3 content was reduced. Notably, at elevated temperature with decreased pH and reduced salinity, the constructed tubes had a more compact ultrastructure with enhanced hardness and elasticity compared to decreased pH at ambient temperature. Thus, elevated temperature rescued the decreased pH-induced tube impairments. This indicates that tubeworms are likely to thrive in early subtropical summer climate. In the context of climate change, tubeworms could be resilient to the projected near-future decreased pH or salinity as long as surface seawater temperature rise at least by 4°C.
Collapse
Affiliation(s)
- Vera B. S. Chan
- Swire Institute of Marine Sciences and School of Biological Sciences, The University of Hong Kong, Hong Kong SAR
| | - Vengatesen Thiyagarajan
- Swire Institute of Marine Sciences and School of Biological Sciences, The University of Hong Kong, Hong Kong SAR
- * E-mail:
| | - Xing Wen Lu
- Department of Civil Engineering, The University of Hong Kong, Hong Kong SAR
| | - Tong Zhang
- Department of Civil Engineering, The University of Hong Kong, Hong Kong SAR
| | - Kaimin Shih
- Department of Civil Engineering, The University of Hong Kong, Hong Kong SAR
| |
Collapse
|
11
|
Lane AC, Mukherjee J, Chan VBS, Thiyagarajan V. Decreased pH does not alter metamorphosis but compromises juvenile calcification of the tube worm Hydroides elegans. MARINE BIOLOGY 2013; 160:1983-1993. [PMID: 24391287 PMCID: PMC3873059 DOI: 10.1007/s00227-012-2056-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 08/23/2012] [Indexed: 05/06/2023]
Abstract
Using CO2 perturbation experiments, we examined the pre- and post-settlement growth responses of a dominant biofouling tubeworm (Hydroides elegans) to a range of pH. In three different experiments, embryos were reared to, or past, metamorphosis in seawater equilibrated to CO2 values of about 480 (control), 980, 1,480, and 2,300 μatm resulting in pH values of around 8.1 (control), 7.9, 7.7, and 7.5, respectively. These three decreased pH conditions did not affect either embryo or larval development, but both larval calcification at the time of metamorphosis and early juvenile growth were adversely affected. During the 24-h settlement assay experiment, half of the metamorphosed larvae were unable to calcify tubes at pH 7.9 while almost no tubes were calcified at pH 7.7. Decreased ability to calcify at decreased pH may indicate that these calcifying tubeworms may be one of the highly threatened species in the future ocean.
Collapse
Affiliation(s)
- Ackley C. Lane
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR
| | - Joy Mukherjee
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR
| | - Vera B. S. Chan
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR
| | - Vengatesen Thiyagarajan
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR
| |
Collapse
|
12
|
Chan VBS, Li C, Lane AC, Wang Y, Lu X, Shih K, Zhang T, Thiyagarajan V. CO(2)-driven ocean acidification alters and weakens integrity of the calcareous tubes produced by the serpulid tubeworm, Hydroides elegans. PLoS One 2012; 7:e42718. [PMID: 22912726 PMCID: PMC3418283 DOI: 10.1371/journal.pone.0042718] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 07/10/2012] [Indexed: 11/30/2022] Open
Abstract
As a consequence of anthropogenic CO2-driven ocean acidification (OA), coastal waters are becoming increasingly challenging for calcifiers due to reductions in saturation states of calcium carbonate (CaCO3) minerals. The response of calcification rate is one of the most frequently investigated symptoms of OA. However, OA may also result in poor quality calcareous products through impaired calcification processes despite there being no observed change in calcification rate. The mineralogy and ultrastructure of the calcareous products under OA conditions may be altered, resulting in changes to the mechanical properties of calcified structures. Here, the warm water biofouling tubeworm, Hydroides elegans, was reared from larva to early juvenile stage at the aragonite saturation state (ΩA) for the current pCO2 level (ambient) and those predicted for the years 2050, 2100 and 2300. Composition, ultrastructure and mechanical strength of the calcareous tubes produced by those early juvenile tubeworms were examined using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and nanoindentation. Juvenile tubes were composed primarily of the highly soluble CaCO3 mineral form, aragonite. Tubes produced in seawater with aragonite saturation states near or below one had significantly higher proportions of the crystalline precursor, amorphous calcium carbonate (ACC) and the calcite/aragonite ratio dramatically increased. These alterations in tube mineralogy resulted in a holistic deterioration of the tube hardness and elasticity. Thus, in conditions where ΩA is near or below one, the aragonite-producing juvenile tubeworms may no longer be able to maintain the integrity of their calcification products, and may result in reduced survivorship due to the weakened tube protection.
Collapse
Affiliation(s)
- Vera Bin San Chan
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, Special Administrative Region, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Allen JD, Pechenik JA. Understanding the effects of low salinity on fertilization success and early development in the sand dollar Echinarachnius parma. THE BIOLOGICAL BULLETIN 2010; 218:189-199. [PMID: 20413795 DOI: 10.1086/bblv218n2p189] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Free-spawning marine invertebrates that live near shore or in estuaries may experience reduced fertilization success during low-salinity events. Although several studies have documented reproductive failure at reduced salinity in estuarine animals, few have looked at whether developmental failure is due to a failure of fertilization or to a failure of fertilized eggs to cleave. In this study, we examined the effects of salinities ranging from 18 to 32 psu on fertilization success and early development in the sand dollar Echinarachnius parma. In addition to decoupling the effects of low salinity on fertilization from its effects on early cleavage, we also assessed whether eggs or sperm were the weak link in accounting for reproductive failure. We found that both fertilization and cleavage failed at salinities below about 22 psu but that development could be partially rescued by returning zygotes to full-strength seawater. We also found that sperm remained active and capable of fertilizing eggs even after being exposed to low salinities for 30 min.. Taken together, these results suggest that reproductive failure at low salinities in E. parma is due more to an inability of the fertilized eggs to cleave than to an inability of sperm to fertilize eggs.
Collapse
Affiliation(s)
- Jonathan D Allen
- Department of Biology, Bowdoin College, Brunswick, Maine 04011, USA.
| | | |
Collapse
|