Oxidative Stress and Antioxidant Defense Mechanisms in Response to Starvation and Refeeding in the Intestine of Stellate Sturgeon (Acipenser stellatus) Juveniles from Aquaculture

Acipenser stellatus is a critically endangered species due to the anthropic influence. It has been intensively captured for decades because of its high economic value, its roe being used in the caviar industry. Therefore, Acipenser stellatus is intensively raised in fish farms for both conservation and economical purposes. Aquaculture aims to optimize the feeding regime of juveniles in order to improve its profitability. The purpose of this study was to investigate if Acipenser stellatus can adapt to a starvation/refeeding regime by assessing the effects of this regime on oxidative stress biomarkers and antioxidant defense mechanisms in juveniles raised under aquaculture conditions. The juveniles were subjected to two regimes: a 7-day starvation period followed by 21 days of refeeding, respectively a 14-day starvation period followed by 21 days of refeeding. The results showed that both starvation/refeeding regimes induced an enhancement of antioxidant enzymes activities in the intestine of the juveniles. The oxidative damage was counteracted at the protein level. However, lipid peroxidation was significantly induced in the intestine of the juveniles subjected to 14/21-day starvation/refeeding regime. The 7/21-day starvation/refeeding regime proved to be more suitable for Acipenser stellatus and therefore, it could be useful to optimize the feeding practice in aquaculture production

Dmrt1 and Cyp17a1 protein detection and relative quantification in Best Beluga hybrid sturgeon gonads

Sturgeons are highly valuable species from both a conservation and economic point of view. Their very sought-after caviar extracted from mature females has both a rich culture around it and opens the way for interesting research. Because of the advanced age at which females and males could be identified in aquaculture it is important to develop a set of molecular markers that could make the distinction easy. For this, a better understanding of the sexual development of sturgeons is necessary. We selected the Dmrt1 (doublesex and mab-3 related transcription factor 1) and the Cyp17a1 (17α-hydroxylase) markers with the scope of investigating the gonad development of sturgeon individuals. Both markers appear to be expressed in the gonad but no statistically significant difference in expression is observed between females and males. This could mean that the markers are equally involved in female and male sexual development at the stage of sampling. This study paves the way for a better understanding of sturgeon sexual development

Expression Characterization of Six Genes Possibly Involved in Gonad Development for Stellate Sturgeon Individuals (Acipenser stellatus, Pallas 1771)

Nowadays, in sturgeon’s aquaculture, there is a necessity for sex identification at early stages in order to increase the efficiency of this commercial activity. The basis for a correct identification is studying the different factors that influence the gonad development. The research has been directed towards molecular methods that have been employed with various degrees of success in identifying genes with different expression patterns between male and female sturgeons during their development stages. For the purpose of understanding the sexual development of 4-year-old stellate sturgeon (Acipenser stellatus) individuals, we have selected six genes (foxl2, cyp17a1, ar, dmrt1, sox9, and star). We analysed the gene expression of the selected genes for gonads, anal fin, liver, body kidney, and white muscle. The cyp17a1, ar, dmrt1, and sox9 genes have a significant higher expression in male gonads than in female gonads, while the data shows no significant differences in the expression of the investigated genes in the other organs. We investigate these genes to shed light on aquaculture sturgeon sexual development

Use of DNA barcoding in the assignment of commercially valuable fish species from Romania

DNA barcoding is a molecular technique frequently used either for biodiversity monitoring and fish conservation or in the identification of the species of origin for raw and processed food from restaurants or fish markets. The most important aspect of this technique is that it works for all stages of life and can be used to distinguish between closely related taxa. Also, the technique has been used to unmask attempts of frauds in fish markets where more desirable and expensive fish are sometimes substituted with lower valued species. Our study aims to test the utility of the COI barcoding gene in the correct identification of several economically and ecologically valuable fish species, and interspecies hybrids, from Romanian wild fauna, aquaculture and fish markets. By combining the 122 COI sequences generated here with additional barcodes downloaded from GenBank and BOLD we screened several members of Acipenseriformes and Salmoniformes. While COI was able to correctly classify the majority of Salmoniformes, the identification process for Acipenseriformes proved more difficult, especially in the case of hybrids. Although the results show that DNA barcodes present a low degree of interspecies variation making classification possible only at the genus level, this technique is still relatively cheap, fast, and useful in the identification of incorrectly labelled market products