Water permeability of the oral epithelial layers of the sea anemone,Anemonia viridis

Bénazet-Tambutté, Sylvie; Allemand, Denis

doi:10.1002/(sici)1097-010x(19970901)279:1<1::aid-jez1>3.0.co;2-t

Cited by 3 publications

(2 citation statements)

References 22 publications

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“…Dykens and Shick (1982) also showed that in the sea anemone Anthopleura elegantissima oxygen could reach ∼ 600 µmol L −1 in the light and ∼ 183 µmol L −1 in the dark, with a variation of ∼ 400 µmol L −1 . Also, variations of pH reported in this study were comparable with those observed in previous experiments (e.g., from 7.3 in the dark to 8.5 in the artificial light (Kühl et al, 1995); from 7.7 in the dark to 8.5 in the daylight (Shashar and Stambler, 1992); from 7.4 in the dark to 8.9 in the artificial light (Furla et al, 1998; Table 2). Kühl et al (1995) showed that pH change from darkness to artificial light is ∼ 1.2 pH units in the scleractinian coral Acropora sp., and Shashar and Stambler (1992) observed a pH variations of ∼ 0.8 pH units in the coral Porites compressa.…”

Section: Discussionsupporting

confidence: 92%

“…Kühl et al (1995) showed that pH change from darkness to artificial light is ∼ 1.2 pH units in the scleractinian coral Acropora sp., and Shashar and Stambler (1992) observed a pH variations of ∼ 0.8 pH units in the coral Porites compressa. Furla et al (1998) found that in sea anemones the pH changes is ∼ 1.5 pH units. We conclude that symbiotic cnidarians and symbiotic dinoflagellates must be adapted to properly function under such extreme conditions (Shashar et al, 1993), which include potential exposure to oxidative stress.…”

Section: Discussionmentioning

confidence: 99%

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The Internal Microenvironment of the Symbiotic Jellyfish Cassiopea sp. From the Red Sea

et al. 2021

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The characterization of the internal microenvironment of symbiotic marine invertebrates is essential for a better understanding of the symbiosis dynamics. Microalgal symbionts (of the family: Symbiodiniaceae) influence diel fluctuations of in host O2 and pH conditions through their metabolic activities (i.e., photosynthesis and respiration). These variations may play an important role in driving oxygen budgets and energy demands of the holobiont and its responses to climate change. In situ measurements using microsensors were used to resolve the O2 and pH diel fluctuations in the oral arms of non-calcifying cnidarian model species Cassiopea sp. (the “upside-down jellyfish”), which has an obligatory association with Symbiodiniaceae. Before sunrise, the internal O2 and pH levels were substantially lower than those in ambient seawater conditions (minimum average levels: 61.92 ± 5.06 1SE μmol O2 L–1 and 7.93 ± 0.02 1SE pH units, respectively), indicating that conditions within Cassiopea’s oral arms were acidified and hypoxic relative to the surrounding seawater. Measurements performed during the afternoon revealed hyperoxia (maximum average levels: 546.22 ± 16.45 1SE μmol O2 L–1) and internal pH similar to ambient levels (8.61 ± 0.02 1SE pH units). The calculated gross photosynthetic rates of Cassiopea sp. were 0.04 ± 0.013 1SE nmol cm–2 s–1 in individuals collected at night and 0.08 ± 0.02 1SE nmol cm–2 s–1 in individuals collected during the afternoon.

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Section: Discussionsupporting

confidence: 92%

Section: Discussionmentioning

confidence: 99%

The Internal Microenvironment of the Symbiotic Jellyfish Cassiopea sp. From the Red Sea

et al. 2021

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Photosynthesis and Calcification at Cellular, Organismal and Community Levels in Coral Reefs: A Review on Interactions and Control by Carbonate Chemistry

Gattuso¹,

Allemand²,

Frankignoulle³

1999

Am Zool

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707

588

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SYNOPSIS. Photosynthesis and calcification in zooxanthellate scleractinian corals and coral reefs are reviewed at several scales: cellular (pathways and transport mechanisms of inorganic carbon and calcium), organismal (interaction between photosynthesis and calcification, effect of light) and ecosystemic (community primary production and calcification, and air-sea CO 2 exchanges).The coral host plays a major role in supplying carbon for the photosynthesis by the algal symbionts through a system similar to the carbon-concentrating mechanism described in free living algal cells. The details of carbon supply to the calcification process are almost unknown, but metabolic CO 2 seems to be a significant source. Calcium supply for calcification is diffusional through oral layers, and active membrane transport only occurs between the calicoblastic cells and the site of calcification. Photosynthesis and calcification are tightly coupled in zooxanthellate scleractinian corals and coral reef communities. Calcification is, on average, three times higher in light than in darkness. The recent suggestion that calcification is dark-repressed rather than light-enhanced is not supported by the literature. There is a very strong correlation between photosynthesis and calcification at both the organism and community levels, but the ratios of calcification to gross photosynthesis (0.6 in corals and 0.2 in reef communities) differ from unity, and from each other as a function of level.The potential effect of global climatic changes (pCO 2 and temperature) on the rate of calcification is also reviewed. In various calcifying photosynthetic organisms and communities, the rate of calcification decreases as a function of increasing pCO 2 and decreasing calcium carbonate saturation state. The calculated decrease in CaCO, production, estimated using the scenarios considered by the International Panel on Climate Change (IPCC), is 10% between 1880 and 1990, and 9-30% (mid estimate: 22%) from 1990 to 2100. Inadequate understanding of the mechanism of calcification and its interaction with photosynthesis severely limits the ability to provide an accurate prediction of future changes in the rate of calcification.

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Low temperature X-ray microanalysis of calcium in a scleractinian coral:evidence of active transport mechanisms

Clode

Marshall

2002

Journal of Experimental Biology

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SUMMARY Element concentrations were measured by X-ray microanalysis in seawater(SW) compartments and mucocytes in bulk, frozen-hydrated preparations of the scleractinian coral Galaxea fascicularis. Quantitative X-ray microanalysis of polyps sampled in the daytime revealed that concentrations of the elements Na, S, K and Ca were all significantly higher in a thin (10-20μm) external SW layer adjacent to the oral ectoderm (P<0.05,<0.05, <0.0001 and <0.01, respectively) than in standard SW. In polyps sampled during night-time, concentrations of Ca and S in this external SW layer were significantly reduced (P<0.05). Ca concentration in the coelenteron and extrathecal coelenteron was significantly higher(P<0.001) than in the external SW layer, regardless of time of sampling, suggesting that Ca2+ transport across the oral epithelium occurs via an active, transcellular route. X-ray microanalyses of mucocytes revealed that the concentration of S was high and did not vary between epithelial layers, while that of Ca increased in an inward gradient toward the skeleton. We suggest that throughout the day, secreted mucus behaves as a Donnan matrix at the oral ectoderm—SW interface,facilitating intracellular Ca2+ uptake. The accumulation within internal SW compartments of high concentrations of Ca relative to standard SW levels, however, appears to be independent of mucus secretion and is likely to be a consequence of active transport processes.

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Water permeability of the oral epithelial layers of the sea anemone,Anemonia viridis

Cited by 3 publications

References 22 publications

The Internal Microenvironment of the Symbiotic Jellyfish Cassiopea sp. From the Red Sea

The Internal Microenvironment of the Symbiotic Jellyfish Cassiopea sp. From the Red Sea

Photosynthesis and Calcification at Cellular, Organismal and Community Levels in Coral Reefs: A Review on Interactions and Control by Carbonate Chemistry

Low temperature X-ray microanalysis of calcium in a scleractinian coral:evidence of active transport mechanisms

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