Allometric relationship between body mass and aerobic metabolism in zebrafish Danio rerio

The relationship between body mass (M) and metabolic rate was investigated through the assessment of active (RA) and standard (RS) metabolic rate at different life stages in zebrafish Danio rerio (5 day-old larvae, 2month-old juveniles and 6 month-old adults). Scaling exponents and constants were assessed for standard (RS =0·273M0·965 in mgO2 g−1 h−1) and active metabolic rate (RA =0·799M0·926 in mgO2 g−1 h−1). These data provide the basis for further experiments regarding the effects of environmental factors on aerobic metabolism throughout the life cycle of this species

Trophic contamination by pyrolytic polycyclic aromatic hydrocarbons does not affect aerobic metabolic scope in zebrafish Danio rerio

International audienceThe effect of trophic exposure to pyrolitic polycyclic aromatic hydrocarbons (PAH) on aerobic metabolism on zebrafish Danio rerio was investigated. There were no significant differences in standard metabolic rate (SMR), active metabolic rate (AMR) or aerobic metabolic scope (AS) at any sub-lethal concentration of PAH in the diet of adult or juvenile zebrafish. This suggests that under these experimental conditions, exposure to PAH in food did not influence aerobic metabolism of this species

Trophic contamination by pyrolytic and petrogenic polycyclic aromatic hydrocarbons: Effects on metabolic and swimming performance in zebrafish: Effects on metabolic and swimming performance in zebrafish <em>(Danio rerio)</em>

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Systematic Screening of Behavioral Responses in Two Zebrafish Strains

Wild-type (WT) zebrafish are commonly used in behavioral tests, but the term WT is not a precise description, and corresponds to many different strains (e.g., AB, TU, WIK, and others). Previous studies compared the physiological, behavioral, or metabolic characteristics of different zebrafish strains (indigenous WT populations versus laboratory WT strains). AB and TU are widely used, but at least one study has demonstrated behavioral differences between them. To choose the most appropriate strain for our experiments, we systematically screened behavioral responses of AB and TU fish in several assays. We analyzed the locomotion activity and responses to a light/dark challenge in adults and larvae, and exploratory behavior and color conditioning in adults. Differences were observed for all tests, the strains displaying particular behavior depending on the tests. As larvae, TU displayed a wider activity range than AB larvae at the onset of locomotor behavior; as adults, TU were more reactive to sudden light transitions and recovered the swimming activity faster in T-maze or homebase release in novel tank tests, whereas AB fish had more contrasted circadian rhythms and performed better in color learning. Strain-specific behavior should be considered when designing experiments using behavior

Long term effects of an early exposure and continuous exposure to pyrolitic PAHs on zebrafish behavioral responses.

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Long term effects of an early exposure to PAHs on Zebrafish behavioural responses

International audiencePolycyclic aromatic hydrocarbons (PAH) emission in the environment is constantly increasing with human activity. The goal of this study was to assess long term consequences of fish early exposure to PAH on behaviour. Eggs were collected from AB zebrafish strain and were placed at 4 hours post fertilization (hpf) until 96 hpf in a 3 cm diameter Petri dish containing 3 g reference sediment either plain (control) or spiked with a mixture of Benzo[a]pyrene, Pyrene and Phenanthrene at environmental concentrations based on values measured in the Seine Estuary (France), a highly polluted site. Thereafter, larvae were transferred in clean water and raised until adulthood. Behavioural tests such as locomotion during 24-hrs, sudden dark change challenge and T-maze exploration were performed at adults’ stage (F0) and sudden dark change on larvae produced by F0 adults. In adults, during night or dark period, contaminated fish were significantly less active than control fish. A similar observation was made for contaminated F0 in T-maze safe area. Contaminated F1 larvae were more active when light was on than control and less active when the light was off. This study indicates that contamination of zebrafish using environmentally relevant concentration during the very first stage of development with a PAH mixture of 3 molecules induced late behavioural effects measured at the adult stage. Further, effect was transmitted to the next generation and behavioural responses of F1 larvae were different to that of F1 control larvae. Consequences on fish abilities (e.g. predator escape, food search, courtship) will be discussed

Chronic dietary exposure to pyrolytic and petrogenic mixtures of PAHs causes physiological disruption in zebrafish—part II: behavior

International audienceIn the last 10 years, behavior assessment has been developed as an indicator of neurotoxicity and an integrated indicator of physiological disruption. Polycyclic aromatic hydrocarbon (PAH) release into the environment has increased in recent decades resulting in high concentrations of these compounds in the sediment of contaminated areas. We evaluated the behavioral consequences of long-term chronic exposure to PAHs, by exposing zebrafish to diets spiked with three PAH fractions at environmentally relevant concentrations. Fish were exposed to these chemicals from their first meal (5 days postfertilization) until they became reproducing adults (at 6 months old). The fractions used were representative of PAHs of pyrolytic (PY) origin and of two oils differing in composition (a heavy fuel oil (HO) and a light crude oil (LO)). Several tests were carried out to evaluate circadian spontaneous swimming activity, responses to a challenge (photomotor response), exploratory tendencies, and anxiety levels. We found that dietary PAH exposure was associated with greater mobility, lower levels of exploratory activity, and higher levels of anxiety, particularly in fish exposed to the HO fraction and, to a lesser extent, the LO fraction. Finally, our results indicate that PAH mixtures of different compositions, representative of situations encountered in the wild, can induce behavioral disruptions resulting in poorer fish performance

Long term effects of an early exposure and continuous exposure to pyrolitic PAHs on zebrafish behavioral responses.

International audienc

Long term effects of an early exposure to PAHs on zebrafish behavioural responses

International audienc