Uptake and release of paralytic shellfish toxins by the clam Ruditapes decussatus exposed to Gymnodinium catenatum and subsequent depuration.
A laboratory experiment was performed with the clam Ruditapes decussatus, fed with the toxic dinoflagellate Gymnodinium catenatum and the non-toxic algae Isochrysis galbana (14 days) and subsequently only with I. galbana (15 days). Individual paralytic shellfish toxins were determined by LC-FLD in G. catenatum cells, whole clam tissues, and particulate organic matter (POM) produced by clams. The toxins dcSTX and dcGTX2 + 3 in the algae were less abundant than C1 + 2 and B1, but were predominant in clams during both the exposure and depuration phases. The toxin dcNEO was only detected in clams during a short period, indicating conversion from other compounds. The toxin composition of the POM indicated the export of dcSTX as faeces or pseudo-faeces along the entire experiment (2.5-14 nmol mg(-1)), B1 was present in a short period of the exposure and C1 + 2 and dcGTX2 + 3 absent. A mass balance calculation indicated that approximately 95% of C1 + 2 and 85% of B1 supplied to the clams were converted into other toxins or lost in solution. Conversely, the net gain of 512, 61 and 31 nmol for dcSTX, dcGTX2 + 3 and dcNEO, respectively, suggests the conversion from other assimilated compounds by clams during exposure and depuration phases.
IPIMAR, Av. Brasília, 1449-006 Lisbon, Portugal. mjoao@ipimar.pt
Maria João
MJ
Botelho
Carlos
C
Vale
Rita Velez
RV
Grilo
João Gomes
JG
Ferreira
D000818:Animals; D049872:Bivalvia / Q000378:metabolism*; D002853:Chromatography, Liquid; D004141:Dinoflagellida / Q000737:chemistry*; D005453:Fluorescence; D058087:Haptophyta / Q000737:chemistry; D008387:Marine Toxins / Q000032:analysis / Q000378:metabolism / Q000493:pharmacokinetics*; D052616:Solid Phase Extraction
D008387:Marine Toxins