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Feeding affects phosphate fluxes in the symbiotic sea anemone Aiptasia pallida

1990; Inter-Research; Volume: 60; Linguagem: Inglês

10.3354/meps060283

1616-1599

Gisèle Muller‐Parker, CB Cook, C.F. D'Elia,

Marine and coastal ecosystems

Phosphate uptake by the anemone Aiptasia pallida occurred only when anemones were starved and was due to the presence of endosymblotic zooxanthellae.Anemones fed Artemia nauplii released ~0 , ~at 0.26 ~L M Pod3-, and showed no evidence of uptake at elevated concentrations (0.66 and 1.26 pM).In contrast, anemones maintained without food for 2 wk to 1 mo took up p o d 3 -at both 0 66 and 1.26 )!M.The uptake of POA3-by anemones freshly collected from the field ([PO,"] = 0.23 btM) was greater than that of anemones fed daily in the laboratory, but less than that of 2-wk to l -m o unfed anemones Replacement of total (host and symbiont) phosphorus (P) solely from uptake of seawater P o d 3 -at 0 66 ~I M would require 374 d in fed anemones, indicating that this source is insignificant in coinparison to ingested food Corresponding times for 2-wk and l -m o starved anemones average less than 8 d , whde those for field anemones average 50 d .Field anemones thus appear to be intermediate between fed-daily and starved anemones with respect to phosphate uptake and P turnover.We conclude that the net flux of phosphate between A. pallida and seawater depends not only on the external seawater concentration, but also on the relat~ve rates of P o d 3 -regeneration by the host and POa3-uptake by the algae, both of which, In turn, are affected by the supply and assimilation of particulate food by the host anemone.