Gallic and pelargonic acids are naturally found in a variety of plants and food products. Despite their extensive use in man-made applications, little is known regarding their potential risks to aquatic vertebrates. The aim of this work was to assess the acute toxicity of these polyphenolic and fatty acid compounds to the zebrafish. In order to get insights into sublethal effects, the enzyme activity of usual biomarkers related to oxidative stress and biotransformation were also assessed in fish. These latter included total superoxide dismutase, catalase as well as total glutathione peroxidase for antioxidant defence mechanisms and glutathione S-transferase for biotransformation related enzyme. Gallic acid was practically non-toxic (96-h lethal concentration (LC50) > 100 mg/L) whereas pelargonic acid was slightly toxic (96-h LC50 of 81.2 mg/L). Moreover, biomarker analyses indicated enhanced superoxide dismutase activity in fish exposed to 20, 40 and 100 mg/L of gallic acid compared to control. A dose-dependent induction of glutathione peroxidase and glutathione S-transferase was reported following gallic acid exposure at the tested concentrations of 10, 20 and 40 mg/L, with the exception of 100 mg/L of substance where basal activity levels were reported. In the case of pelargonic acid, there was no change in antioxidant enzyme activity while an inhibition of glutathione S-transferase was observed from organisms exposed to 45, 58 and 76 mg/L of test solution. The results concerning sublethal effects on biological parameters of zebrafish highlighted thereby the need for further investigations following chronic exposure to both organic acids.

The domestication process is accompanied with adaptation of the animals to captive conditions. It induces changes at different levels thereby affecting a variety of biological functions. While there is abundant literature on the domestication effects on growth and stress response in teleosts, the effects on reproduction have received limited attention. In this work, we investigated the domestication effect on reproductive ability of Eurasian perch (Perca fluviatilis L.), a promising candidate for the development of European aquaculture and whose reproductive physiological processes through the domestication history has not been questioned yet.To address this question, two populations of F1 and "domesticated" females were submitted to a photothermal program allowing the control of gonadogenesis advancement. Gonadosomatic index, 17 β-estradiol levels and oocyte diameter were significantly higher in domesticated population than in F1 one. In contrast, testosterone, 11-ketotestosterone, and vitellogenin levels were found to be higher in F1 females than in their domesticated counterparts. Lower reproductive performance were observed in the domesticated population compared to the F1 one in terms of survival rate, hatching rate, percentage of eyed stage larvae and percentage of malformations. In conclusion, this study shows that, in this example of domestication process, despite a positive effect on the precocious gonadogenesis advancement and vitellogenesis progress this domestication route negatively affected the reproductive performance.

No abstract