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Cadmium (Cd) is commonly detected in aquatic environment and can accumulate in maricultural organisms. Modification of the food may change the bio-kinetics of trace metals in organisms. The aim of this study was to understand the effects of food type on the uptake and elimination of Cd in different tissues of oyster Crassostrea gigas. Oyster groups feeding with different food types were exposed to 10 μg/L Cd for 28 days, and then followed by a depuration of 35 days. One group was added natural seawater rich in algae, the other three groups were fed once daily with Dicrateria inornata, Nitzschia closterium f.minutissima and mixed alga (Dicrateria inornata: Nitzschia closterium f.minutissima=1:1), respectively. Oysters were sampled for chemical analysis by inductively coupled plasma mass spectrometry (ICP-MS). The mean concentrations of Cd among different oyster tissue were followed the order as: digestive gland > mantle > adductor muscle. A two-compartment model was used to estimate Cd uptake rates (k1), depuration rates (k2), bioconcentration factor (BCF), and half-lives (t1/2) in the three tissues, showing k1 was considerately higher than k2, therefore, the organism have high ability to accumulate Cd. The k1 in the digestive gland was the highest, followed by mantle and adductor muscle, while the k2 in the mantle was the lowest. In the present study, the group fed with mixed algae showed the fastest depuration rate and the shortest t1/2 in the important edible part of the oysters (digestive gland), which helps to improve food safety.

Background Variation in early nutrition is known to play an important role in shaping the behavioural development of individuals. Parental prey selection may have long-lasting behavioural influences. In birds foraging on arthropods, for instance, the specific prey types, e.g. spiders and caterpillars, matter as they have different levels of taurine which may have an effect on personality development. Here we investigated how naturally occurring variation in the amounts of spiders and caterpillars, provisioned to nestlings at day 4 and 8 after hatching, is related to the response to handling stress in a wild passerine, the great tit (Parus major). Broods were cross-fostered in a split-brood design allowing us to separate maternal and genetic effects from early rearing effects. Adult provisioning behaviour was monitored on day four and day eight after hatching using video recordings. Individual nestlings were subjected to a handling stress test at an age of 14 days, which is a validated proxy for exploratory behaviour as an adult. Results - Variation in handling stress was mainly determined by the rearing environment. We show that, contrary to our predictions, not the amount of spider biomass, but the amount of caterpillar biomass delivered per nestling significantly affected individual performance in the stress test. Chicks provisioned with lower amounts of caterpillars exhibited a stronger stress response, reflecting faster exploratory behaviour later on in life, than individuals who received larger amounts of caterpillars. Conclusions - These results suggest that natural variation in parental behaviour in wild birds modulates the developmental trajectories of their offspring's personality via food provisioning. Since parental provisioning behaviour might also reflect the local environmental conditions, provisioning behaviour may influence how nestlings respond to these local environmental conditions.

Resource polymorphisms, intraspecific variation in morphology due to differential resource use, are common across a wide range of animal taxa. The focus in studies of such polymorphisms has been on external morphology, but the differential use of food resources could also influence other phenotypic traits such as the digestive performance. In the present study, we experimentally demonstrate that Eurasian perch (Perca fluviatilis L.) display adaptive plasticity in gut length when exposed to different food types. Perch fed a less digestible food type developed relatively longer guts compared to fish fed a more easily digested food type. This divergence in gut length was also apparent under natural conditions because perch inhabiting the littoral and pelagic habitats of a lake differed in resource use and relative gut length. Despite that the digestive system in perch is plastic, we found that individuals switching to a novel food type might experience an initial fitness cost of the diet switch in the form of a temporary reduction in body condition. These results show the importance of gut length plasticity for an ontogenetic omnivore but also a cost that might prevent diet switching in polymorphic populations.