Effect of capture by longline in the RNA / DNA ratio and oxidative stress in the shark Carcharhinus falciformis (Müller & Henle, 1839) in the Mexican central Pacific

This research focused to identify potential relationships of transcriptomics tracers and oxidative stress, regarding the process of capture by longline of shark Carcharhinus falciformis . During February 2010 and May 2012 in the Eastern Pacific Ocean, were captured individuals of C. falciformis , in each it was determined sex, state of maturity and morphometric data. Samples were taken from muscle tissue to determine RNA, DNA and proteins concentrations, and thus the RNA/DNA, Protein/DNA ratios were calculated. Indicators of oxidative stress [superoxide dismutase (SOD), glutathione (GSH), and malondialdehyde (MDA)], were determined in muscle, blood and plasma. A total of 159 specimens were captured (93 juveniles and 66 adults). Results showed low values in the RNA/DNA ratio of the different maturity stages, reflected a basal state in the transcriptomics capacity, which could be caused by physiological stress promoted by the physical effort associated with fishing. Regarding RNA/DNA ratio and SOD activity, it could recognize an inverse correlation related to size and age, as well a decrease in the protein/DNA ratio, which was associated to protein synthesis in muscle tissue, according to the organisms reach adulthood. Results showed in this study suggest a pattern of decreased ability antioxidant response regarding increased age elasmobranches.