TP3 Metals in the Environment: Dietary Concerns in Aquatic Systems
254 Portland Ballroom
1:20 PM - 4:40 PM, Tuesday
() Influences of subcellular metal compartmentalization on the trophic transfer to a predatory gastropod from different prey.
Cheung, Ma Shan1, Wang, Wen-Xiong2, 1 Atmosphic, Marine, Coastal Environment Programme, Hong Kong University of Science and Technology, Hong Kong, China2 Department of Biology, Hong Kong University of Science and Technology, Hong Kong, China
ABSTRACT- Marine gastropods Thais clavigera accumulate high metal concentrations in their bodies and trophic transfer of metals plays an important role in metal bioaccumulation. We firstly examined the relationship between the subcellular metal distribution in the prey (barnacles, mussels, oysters, herbivorous gastropods and limpets) and the assimilation efficiency (AE) of metals in T. clavigera. We then modified the metal subcellular distribution of oyster, Saccostrea cucullata, using different exposure regime, and the AEs of metals in T.clavigera were quantified. Further, we purified the subcellular fractions of preys and determined how the biochemical properties of different fractions affected the AEs of metals. The AE of metals from different prey was similar. Significant relationship was found between the AE of Cd and the MRG and MTLP fractions, and between the AE of Zn and the trophically available metal fraction. The AEs of different metals were high, ranging from 50 - 90%. For T.clavigera fed on oyster with different metal partitioning, the AEs of different metals ranging from 60 - 90%, which were not related to the metal partitioning in the oysters. Uptake of metals was similar from different subcellular fractions. T. clavigera assimilated 60 - 85% from the insoluble fraction, 40 - 80% from the heat sensitive protein, 45 - 90% from MTLP, and 40 - 80% from the metal-rich granules. Our results imply that metals bound with the insoluble fraction were also bioavailable to T. clavigera. This study may help to better understand the toxicity of dietary metals to top predators.
Key words: trophic transfer, metals, Thais clavigera, subcellular metals distribution