scholarly journals Impact of diurnal temperature fluctuations on larval settlement and growth of the reef coral <i>Pocillopora damicornis</i>

2017 ◽  
Author(s):  
Lei Jiang ◽  
You-Fang Sun ◽  
Yu-Yang Zhang ◽  
Guo-Wei Zhou ◽  
Xiu-Bao Li ◽  
...  
Keyword(s):  
Larval Settlement ◽  
Seawater Temperature ◽  
Reef Coral ◽  
Temperature Fluctuations ◽  
Maximum Temperature ◽  
Pocillopora Damicornis ◽  
Positive Effects ◽  
Early Stages ◽  
Tropical Reef ◽  
Excitation Pressure

Abstract. Diurnal fluctuations in seawater temperature are ubiquitous on tropical reef flats. However, effects of such dynamic temperature variations on the early stages of corals are poorly understood. Here, we investigated the responses of larvae and new spats of Pocillopora damicornis to two constant temperature treatments (29 and 31 °C), and two diurnally fluctuating treatments (28–31 and 30–33 °C with daily means of 29 and 31 °C, respectively) simulating the 3 °C diel oscillations at 3 m depth on Luhuitou fringing reef (Sanya, China). Results showed that the thermal stress on settlement at 31 °C was almost negated by the fluctuating treatment. Further, temperature fluctuations did not exacerbate bleaching responses but alleviated the maximum excitation pressure over photosystem Ⅱ (PSⅡ). Although early growth and development were highly stimulated at 31 °C, oscillations of 3 °C had little effects on budding and lateral growth. Nevertheless, daytime encounters with the maximum temperature of 33 °C elicited a notable reduction in calcification. These results underscore the complexity in the effects caused by diel temperature fluctuations on early stages of corals, and suggest that the ecologically relevant temperature variability could buffer the warming stress on larval settlement and dampen the positive effects of increased temperatures on coral growth.

scholarly journals Impact of diurnal temperature fluctuations on larval settlement and growth of the reef coral <i>Pocillopora damicornis</i>

2017 ◽  
Vol 14 (24) ◽  
pp. 5741-5752 ◽  
Author(s):  
Lei Jiang ◽  
You-Fang Sun ◽  
Yu-Yang Zhang ◽  
Guo-Wei Zhou ◽  
Xiu-Bao Li ◽  
...  
Keyword(s):  
Larval Settlement ◽  
Seawater Temperature ◽  
Reef Coral ◽  
Temperature Fluctuations ◽  
Maximum Temperature ◽  
Pocillopora Damicornis ◽  
Positive Effects ◽  
Early Stages ◽  
Tropical Reef ◽  
New Recruits

Abstract. Diurnal fluctuations in seawater temperature are ubiquitous on tropical reef flats. However, the effects of such dynamic temperature variations on the early stages of corals are poorly understood. In this study, we investigated the responses of larvae and new recruits of Pocillopora damicornis to two constant temperature treatments (29 and 31 °C) and two diurnally fluctuating treatments (28–31 and 30–33 °C with daily means of 29 and 31 °C, respectively) simulating the 3 °C diel oscillations at 3 m depth on the Luhuitou fringing reef (Sanya, China). Results showed that the thermal stress on settlement at 31 °C was almost negated by the fluctuating treatment. Further, neither elevated temperature nor temperature fluctuations caused bleaching responses in recruits, while the maximum excitation pressure over photosystem II (PSII) was reduced under fluctuating temperatures. Although early growth and development were highly stimulated at 31 °C, oscillations of 3 °C had little effects on budding and lateral growth at either mean temperature. Nevertheless, daytime encounters with the maximum temperature of 33 °C in fluctuating 31 °C elicited a notable reduction in calcification compared to constant 31 °C. These results underscore the complexity of the effects caused by diel temperature fluctuations on early stages of corals and suggest that ecologically relevant temperature variability could buffer warming stress on larval settlement and dampen the positive effects of increased temperatures on coral growth.

scholarly journals Subcellular Investigation of Photosynthesis-Driven Carbon Assimilation in the Symbiotic Reef Coral Pocillopora damicornis

mBio ◽  
2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Christophe Kopp ◽  
Isabelle Domart-Coulon ◽  
Stephane Escrig ◽  
Bruno M. Humbel ◽  
Michel Hignette ◽  
...  
Keyword(s):  
Lipid Droplets ◽  
Secondary Ion Mass Spectrometry ◽  
Reef Coral ◽  
Carbon Assimilation ◽  
Isotopic Labeling ◽  
Cellular Level ◽  
Coral Tissue ◽  
Pocillopora Damicornis ◽  
Carbon And Nitrogen ◽  
Transmission Electron

ABSTRACT  Reef-building corals form essential, mutualistic endosymbiotic associations with photosynthetic Symbiodinium dinoflagellates, providing their animal host partner with photosynthetically derived nutrients that allow the coral to thrive in oligotrophic waters. However, little is known about the dynamics of these nutritional interactions at the (sub)cellular level. Here, we visualize with submicrometer spatial resolution the carbon and nitrogen fluxes in the intact coral-dinoflagellate association from the reef coral Pocillopora damicornis by combining nanoscale secondary ion mass spectrometry (NanoSIMS) and transmission electron microscopy with pulse-chase isotopic labeling using [13C]bicarbonate and [15N]nitrate. This allows us to observe that (i) through light-driven photosynthesis, dinoflagellates rapidly assimilate inorganic bicarbonate and nitrate, temporarily storing carbon within lipid droplets and starch granules for remobilization in nighttime, along with carbon and nitrogen incorporation into other subcellular compartments for dinoflagellate growth and maintenance, (ii) carbon-containing photosynthates are translocated to all four coral tissue layers, where they accumulate after only 15 min in coral lipid droplets from the oral gastroderm and within 6 h in glycogen granules from the oral epiderm, and (iii) the translocation of nitrogen-containing photosynthates is delayed by 3 h. IMPORTANCE  Our results provide detailed in situ subcellular visualization of the fate of photosynthesis-derived carbon and nitrogen in the coral-dinoflagellate endosymbiosis. We directly demonstrate that lipid droplets and glycogen granules in the coral tissue are sinks for translocated carbon photosynthates by dinoflagellates and confirm their key role in the trophic interactions within the coral-dinoflagellate association.

scholarly journals The early larval development of the tropical reef lobster Enoplometopus antillensis Lütken (Astacidea, Enoplometopidae) reared in the laboratory

2007 ◽  
Vol 24 (2) ◽  
pp. 382-396 ◽  
Author(s):  
Fernando A. Abrunhosa ◽  
Max W. P. Santana ◽  
Marcus A. B. Pires
Keyword(s):  
Larval Development ◽  
Water Tank ◽  
Dunaliella Viridis ◽  
Early Stages ◽  
Tropical Reef ◽  
Early Larval Development

The early stages of the tropical reef lobster Enoplometopus antillensis Lütken, 1865 were described and illustrated in detail from specimens reared in the laboratory. Ovigerous females were captured in their habitat, at a depth of about 15 meters and transported to the laboratory. The larvae were reared in a recirculation water tank for approximately 15 days and then transferred to four 10 liters aquariums. The larvae were fed on Artemia sp. nauplii. Microalgae Dunaliella viridis was added daily to the culture. The larvae moulted seven times progressing through the zoea VIII. Megalopa stage was not achieved. The intermoulting period of each stage averaged from eight to 12 days. Morphological comparisons with previous reports are briefly discussed.

Calcified macroalgae and their bacterial community in relation to larval settlement and metamorphosis of reef-building coral Pocillopora damicornis

2020 ◽  
Vol 97 (1) ◽  
Author(s):  
Fangfang Yang ◽  
Jiahao Mo ◽  
Zhangliang Wei ◽  
Lijuan Long
Keyword(s):  
Bacterial Community ◽  
Community Composition ◽  
Bacterial Community Composition ◽  
Larval Settlement ◽  
Pocillopora Damicornis ◽  
Principal Coordinates Analysis ◽  
Principal Coordinates ◽  
Coral Reef Ecosystems ◽  
Settlement And Metamorphosis ◽  
Invertebrate Larvae

ABSTRACT Calcified macroalgae play an important role in the settlement and metamorphosis of invertebrate larvae in coral reef ecosystems. However, little is known about the algal-associated bacterial communities and their effects on larval settlement. In this study, the responses of larvae of the coral Pocillopora damicornis to calcified algae (Porolithon onkodes, Halimeda cylindracea, Halimeda opuntia and Amphiroa fragilissima) were evaluated. The results revealed that Por. onkodes and H. cylindracea significantly enhanced the rates of settlement and metamorphosis, whereas fewer larvae settled on Am. fragilissima and H. opuntia. Amplicon pyrosequencing of the V3–V4 region of 16S rDNA was applied to investigate the relationship between algal bacterial community and larval settlement. Principal coordinates analysis demonstrated that the bacterial community composition of H. opuntia was more similar to that of Am. fragilissima, but clearly distinct from those of H. cylindracea and Por. onkodes. Furthermore, the relative abundances of bacteria were highly diverse among different algae. H. opuntia had higher percentages of Thalassobius, Pelagibius and SM1A02, whereas the abundances of Mycoplasma and Suttonella were significantly higher in H. cylindracea than other algae. Our results showed that larval settlement/metamorphosis was strongly correlated with the bacterial community composition and with the relative abundance of a few operational taxonomic units.

scholarly journals Effects of diurnal warming on soil respiration are not equal to the summed effects of day and night warming in a temperate steppe

2009 ◽  
Vol 6 (8) ◽  
pp. 1361-1370 ◽  
Author(s):  
J. Xia ◽  
Y. Han ◽  
Z. Zhang ◽  
Z. Zhang ◽  
S. Wan
Keyword(s):  
Soil Respiration ◽  
Temperature Increase ◽  
Maximum Temperature ◽  
Daily Minimum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Temperate Steppe ◽  
Positive Effects ◽  
Diurnal Warming ◽  
Night Warming

Abstract. The magnitude of daily minimum temperature increase is greater than that of daily maximum temperature increase under climate warming. This study was conducted to examine whether changes in soil respiration under diurnal warming are equal to the summed changes under day and night warming in a temperate steppe in northern China. A full factorial design with day and night warming was used in this study, including control, day (06:00 a.m.–06:00 p.m., local time) warming, night (06:00 p.m.–06:00 a.m.) warming, and diurnal warming. Day warming showed no effect on soil respiration, whereas night warming significantly increased soil respiration by 7.1% over the 3 growing seasons in 2006–2008. The insignificant effect of day warming on soil respiration could be attributable to the offset of the direct positive effects of increased temperature by the indirect negative effects via aggravating water limitation and suppressing ecosystem C assimilation. The positive effects of night warming on soil respiration were largely due to the stimulation of ecosystem C uptake and substrate supply via overcompensation of plant photosynthesis. Changes in both soil respiration (+20.7 g C m−2 y−1) and GEP (−2.8 g C m−2 y−1) under diurnal warming are smaller than their summed changes (+40.0 and +24.6 g C m−2 y−1, respectively) under day and night warming. Our findings that the effects of diurnal warming on soil respiration and gross ecosystem productivity are not equal to the summed effects of day and night warming are critical for model simulation and projection of climate-carbon feedback.

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