Consulta: subjectFacets:"Mixotrophy"
Registros recuperados: 4
Data/hora: 27/07/2024 01:44:08

Isotopic and elemental compositions reveal density‐dependent nutrition pathways in a population of mixotrophic jellyfish
Provedor de dados: 5
Autores: Djeghri, Nicolas; Pondaven, Philippe; Stockenreiter, Maria; Behl, Stephan; Huang, Jessica Y. T.; Hansen, Thomas; Patris, Sharon; Ucharm, Gerda; Stibor, Herwig.
Mixotrophic organisms are increasingly recognized as important components of ecosystems, but the factors controlling their nutrition pathways (in particular their autotrophy–heterotrophy balance) are little known. Both autotrophy and heterotrophy are expected to respond to density‐dependent mechanisms but not necessarily in the same direction and/or strength. We hypothesize that the autotrophy–heterotrophy balance of mixotrophic organisms might therefore be a function of population densities. To investigate this relationship, we sampled mixotrophic jellyfish holobionts (host, Mastigias papua etpisoni; symbiont, Cladocopium sp.) in a marine lake (Palau, Micronesia) on six occasions (from 2010 to 2018). Over this period, population densities varied ~100...
Tipo: Text
Palavras-chave: Density dependence; Jellyfish; Marine lakes; Mixotrophy; Stable isotopes; Symbiosis; Zooxanthellae.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00663/77469/79159.pdf

Light and dark carbon uptake by Dinophysis species in comparison to other photosynthetic and heterotrophic dinoflagellates
Provedor de dados: 5
Autores: Graneli, Edna; Anderson, Donald M; Carlsson, Per; Maestrini, Serge Y.
The marine dinoflagellate genus Dinophysis includes species that are the causative agents of diarrhetic shellfish poisoning (DSP). Recent findings indicate that some Dinophysis species are mixotrophic, i.e. capable of both autotrophic and heterotrophic nutrition. We investigated inorganic (and organic) carbon uptake by several species of Dinophysis in the Light and dark using the 'single-cell C-14 method', and compared uptake rates with those of photosynthetic Ceratium species and heterotrophic dinoflagellates in the genus Protoperidinium. Experiments were conducted with water from the Gullmar Fjord and from the Koster Strait (Swedish west coast). Nutrient-enriched phytoplankton from surface water samples were concentrated (20 to 70 mu m) and incubated at...
Tipo: Text
Palavras-chave: Dinophysis; Growth rate; Mixotrophy; Carbon uptake; Ceratium; Protoperidinium.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00336/44679/45050.pdf

Paramétrisation de la nutrition azotée et phosphorée d'Alexandrium catenella, microalgue toxique responsable d'efflorescences dans la lagune de Thau
Provedor de dados: 5
Autores: Jauzein, Cecile.
In the Thau lagoon, blooms of the toxic microalgae Alexandrium catenella have induced regular losses of shellfish production since 1998 due to bioaccumulation of toxins in oysters and mussels. This thesis was conducted to enhance knowledge of toxic bloom development regulation by environmental factors, focusing on nitrogen and phosphorus nutrients influence on A. catenella growth. These works highlighted a large variety of potential nutritive sources for this species and a major part of these nutrients appeared to be potentially regenerated in the water column. Different organic sources may contribute to the growth of A. catenella from diverse nutrition processes: direct absorption through the cell membrane (for urea), enzymatic degradation in the...
Tipo: Text
Palavras-chave: Alkaline phosphatases; Mixotrophy; Phosphate; Urea; Ammonium; Uptake kinetics; Alexandrium catenella; Phosphatases alcalines; Mixotrophie; Phosphate; Urée; Ammonium; Cinétiques d'absorption; Alexandrium catenella.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/these-6511.pdf

δ13C, δ15N, and C:N ratios as nutrition indicators of zooxanthellate jellyfishes: insights from an experimental approach
Provedor de dados: 5
Autores: Djeghri, Nicolas; Stibor, Herwig; Lebeau, Oanez; Pondaven, Philippe.
Some jellyfish host zooxanthellae in their tissues (mostly from the family Symbiodiniaceae; Dinophyceae) and supplement their heterotrophic nutrition with their symbiont's photosynthates. The mixotrophy of zooxanthellate jellyfishes (as holobionts) renders the study of their nutrition, growth, and population dynamics complicated. Here, we used an experimental approach to assess how carbon and nitrogen stable isotopes (δ13C and δ15N) as well as the elemental composition (C:N ratios) of zooxanthellate jellyfishes are affected by variations in nutrition sources: i. e. predation (heterotrophic) versus photosynthesis (autotrophic). Our laboratory experiment, conducted on the zooxanthellate jellyfish Cassiopea sp. medusae (including symbionts) in the presence or...
Tipo: Text
Palavras-chave: Stable isotopes; C:N ratios; Photosymbiosis; Mixotrophy; Scyphozoa; Zooxanthellae.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00591/70348/68448.pdf