The effect of ammonium on photosynthesis and the pathway of ammonium assimilation in
            <i>Gymnodinium microadriaticum in vitro</i>
            and in symbiosis with tridacnid clams and corals

Summons, Roger E.; Boag, T. S.; Osmond, C. B.

doi:10.1098/rspb.1986.0016

Cited by 36 publications

(11 citation statements)

References 23 publications

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“…was considerably enhanced under sunlight, indicating a stimulation of ammonium uptake by photosynthesis. This effect has also been found for other zooxanthellae-bearing organisms, such as the coral Stylophora pistillata (Grover et al 2002) and other hosts (Summons et al 1986). The jellyfish revealed a high photosynthetic efficiency under high light levels (as demonstrated by the RLCs), comparable to corals under similar light intensities (Ralph et al 1999(Ralph et al , 2002.…”

Section: Nutrient Uptakementioning

confidence: 81%

Enhanced pore-water nutrient fluxes by the upside-down jellyfish Cassiopea sp. in a Red Sea coral reef

Jantzen¹,

Wild²,

Rasheed³

et al. 2010

Mar. Ecol. Prog. Ser.

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The common circum-tropical jellyfish Cassiopea sp., unlike other members of the Rhizostomidae (Scyphozoa), exhibits a primarily benthic life. The peculiar orientation of its exumbrella against the sediment is believed to be associated with its mainly autotrophic nutrition, i.e. exposing its zooxanthellae-bearing photosynthetic oral appendages to the sunlight. Here we show that the jellyfish also acts as a nutrient pump, drawing nutrient-rich pore waters from the permeable sediments. Depletion of pore-water ammonium in situ, light-enhanced ammonium uptake, and high rates of photosynthesis determined via oxygen flux measurements and underwater fluorometer analysis (rapid light curves) show that Cassiopea sp. effectively harnesses pore-water nutrients. At high densities Cassiopea sp. may facilitate benthic-pelagic coupling and primary production in oligotrophic coral reefs.KEY WORDS: Cassiopea sp. · Upside-down jellyfish · Advective pore-water transport · Nutrient uptake · Nutrient regeneration · Sediment · Photosynthesis · Zooxanthellae Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 411: [117][118][119][120][121][122][123][124][125] 2010 sporine acids (Banaszak & Trench 1995), as demonstrated for corals and giant clams (Shick et al. 1995, Ishikura et al. 1997. Furthermore, Cassiopea sp. has a special blue mesogloeal protein that serves as a shield against damaging solar radiation, while simultaneously allowing photosynthetically active wavelengths to reach the zooxanthellae (Blanquet & Phelan 1987).Cassiopea sp. has an upside-down orientation, with the exumbrella facing the substrate, its beating motion and mucus (Gohar & Eisawy 1960) fixing the animal in place so that 'especially the larger ones would not ordinarily leave the bottom' (Bigelow 1900, p. 191). This unusual modus vivendi of Cassiopea sp. has prompted speculations that the jellyfish's activity may represent a mechanism to maintain its position with respect to sunlight, thus enabling prolonged exposure of the zooxanthellae-laden oral appendages and the subumbrella (Gohar & Eisawy 1960). It has also been considered a feeding strategy, whereby autotrophic nutrition is accomplished via the capture of interstitial microorganisms flushed across its oral appendages (Larson 1997), entangled in mucus, and subsequently consumed by the many secondary mouths (Bigelow 1900). Nutrient requirements for photosynthesis may partly be met by this digestion of plankton or suspended organic matter.Cassiopea sp. usually occurs on sandy patches in coral reefs, seagrass beds or mangroves characterised by calm waters. These permeable sandy sediments function as large-scale filter systems (e.g. Hansen et al. 1992, Holguin et al. 2001, where accumulated organic material is effectively decomposed by high abundances of heterotrophic microbes ) and regenerated nutrients are stored interstitially (Rasheed et al. 2002, Wild et al. 2005. Sedimentary nutrient recycling is mainly achieved by anaerobic microbes below a rat...

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Section: Nutrient Uptakementioning

confidence: 81%

Enhanced pore-water nutrient fluxes by the upside-down jellyfish Cassiopea sp. in a Red Sea coral reef

Jantzen¹,

Wild²,

Rasheed³

et al. 2010

Mar. Ecol. Prog. Ser.

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“…Enzymatic assays and HPLC-analysis of internal FAA pools have demonstrated that in the cnidarian host, ammonium assimilation occurs largely by the NADP-glutamate dehydrogenase (NADP-GDH) pathway; this catalyzes the conversion of ammonium to the amino acid glutamate (242,315), a precursor of other amino acids. Ammonium assimilation in the dinoflagellate symbionts is instead by the glutamine synthetase/glutamine 2-oxoglutarate amido transferase (GS/GOGAT) pathway, but the end product is again glutamate (315,350,413). Only the dinoflagellate partner can convert nitrate to ammonium for subsequent assimilation into amino acids.…”

Section: Fluxes Of Nitrogen and Phosphorusmentioning

confidence: 99%

Cell Biology of Cnidarian-Dinoflagellate Symbiosis

Davy

Allemand

Weis

2012

Microbiol Mol Biol Rev

836

1,041

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SUMMARY The symbiosis between cnidarians (e.g., corals or sea anemones) and intracellular dinoflagellate algae of the genus Symbiodinium is of immense ecological importance. In particular, this symbiosis promotes the growth and survival of reef corals in nutrient-poor tropical waters; indeed, coral reefs could not exist without this symbiosis. However, our fundamental understanding of the cnidarian-dinoflagellate symbiosis and of its links to coral calcification remains poor. Here we review what we currently know about the cell biology of cnidarian-dinoflagellate symbiosis. In doing so, we aim to refocus attention on fundamental cellular aspects that have been somewhat neglected since the early to mid-1980s, when a more ecological approach began to dominate. We review the four major processes that we believe underlie the various phases of establishment and persistence in the cnidarian/coral-dinoflagellate symbiosis: (i) recognition and phagocytosis, (ii) regulation of host-symbiont biomass, (iii) metabolic exchange and nutrient trafficking, and (iv) calcification. Where appropriate, we draw upon examples from a range of cnidarian-alga symbioses, including the symbiosis between green Hydra and its intracellular chlorophyte symbiont, which has considerable potential to inform our understanding of the cnidarian-dinoflagellate symbiosis. Ultimately, we provide a comprehensive overview of the history of the field, its current status, and where it should be going in the future.

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“…The question as to whether corals act~vely regulate the availability of nutrients to zooxanthellae remains unanswered. However, recent evidence supporting the existence of an ammonium-concentrating mechanism in clams and corals (Summons et al 1986) and the identification of a cytosolic N A D P H -d e p e n d e n t glutam a t e d e h y d r o g e n a s e u n i q u e to symbiotic corals (Dudler e t al. 1987) d o e s s u g g e s t t h a t s o m e corals m a y h a v e t h e facility to regulate t h e concentration of a m m o n i u m in t h e i m m e d i a t e extracellular environment of t h e zooxanthellae.…”

Section: Photosynthesis and Respirationmentioning

confidence: 99%

Influence of the population density of zooxanthellae and supply of ammonium on the biomass and metabolic characteristics of the reef corals Seriatopora hystrix and Stylophora pistillata

Høegh-Guldberg¹,

Smith²

1989

Mar. Ecol. Prog. Ser.

183

101

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In May 1987, the population density of zooxanthellae in the reef coral Seriatopora hystrix around Lizard Island (Great Barrier Reef) varied within and between colonies. This naturally occurring variabhty made it possible to examine the effect of the population density of zooxanthellae on the physiological characteristics of S. hystnx and its zooxanthellae. As the population density of zooxanthellae increased, the chlorophylla content and maximum rate of photosynthesis of the zooxanthellae decreased. Phytoplankton studies suggest that cellular chlorophyll content will increase if cells are selfshaded or will decrease if cells are nitrogen-limited. To test the hypothesis that zooxanthellae in S. hystrix and Stylophora pistillata are nitrogen-limited at their highest population densities, colonies of S. hystrix and S. pistillata with high densities of zooxanthellae were incubated in aquaria to which ammonium (ca 10 to 40pfi4) was added at regular intervals. After 3wk, the population density, chlorophylla content and maximum rate of photosynthesis of the zooxanthellae had significantly increased, indicating that the biomass of zooxanthellae in reef corals can be lirmted by the availability of inorganic nitrogen to the association.

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The effect of ammonium on photosynthesis and the pathway of ammonium assimilation in Gymnodinium microadriaticum in vitro and in symbiosis with tridacnid clams and corals

Cited by 36 publications

References 23 publications

Enhanced pore-water nutrient fluxes by the upside-down jellyfish Cassiopea sp. in a Red Sea coral reef

Enhanced pore-water nutrient fluxes by the upside-down jellyfish Cassiopea sp. in a Red Sea coral reef

Cell Biology of Cnidarian-Dinoflagellate Symbiosis

Influence of the population density of zooxanthellae and supply of ammonium on the biomass and metabolic characteristics of the reef corals Seriatopora hystrix and Stylophora pistillata

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