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Minimization of stress during the transportation of live fish is essential in maintaining the welfare and performance of the animals. In order to test the hypothesis that stress during transport of fingerlings of Nile tilapia (Oreochromis niloticus) can be reduced with the aid of the anesthetics menthol, eugenol or benzocaine, we have assessed the effects of these agents at various concentrations on the physiological parameters and survival rates of fish subjected to conditions simulating those normally used in transportation. Fingerlings (N = 1200) were fasted for 24 hours and distributed in 20 L polyethylene bags (N = 50 per bag) containing 5 L of water and an anesthetic at the appropriate concentration. Fingerlings treated with menthol at 75 mg L-1, or eugenol or benzocaine at 20 mg L-1, maintained levels of plasma cortisol and glucose that were lower than those of the stressed but untreated controls and within the physiological limits of the baseline values for this species. Under these conditions, the survival rate was 100%, suggesting that stress was substantially reduced despite dense consignment. Treatments involving higher doses of the studied agents induced significant anesthetic toxicity. Minimization of stress during the transportation of live fish is essential in maintaining the welfare and performance of the animals. In order to test the hypothesis that stress during transport of fingerlings of Nile tilapia (Oreochromis niloticus) can be reduced with the aid of the anesthetics menthol, eugenol or benzocaine, we have assessed the effects of these agents at various concentrations on the physiological parameters and survival rates of fish subjected to conditions simulating those normally used in transportation. Fingerlings (N = 1200) were fasted for 24 hours and distributed in 20 L polyethylene bags (N = 50 per bag) containing 5 L of water and an anesthetic at the appropriate concentration. Fingerlings treated with menthol at 75 mg L-1, or eugenol or benzocaine at 20 mg L-1, maintained levels of plasma cortisol and glucose that were lower than those of the stressed but untreated controls and within the physiological limits of the baseline values for this species. Under these conditions, the survival rate was 100%, suggesting that stress was substantially reduced despite dense consignment. Treatments involving higher doses of the studied agents induced significant anesthetic toxicity.

This study aims to evaluate the effect of different initial densities of Nile tilapia fingerlings on water quality, fish growth, and production of marjoram (Origanum majorana L.) and sweet basil (Ocimum basilicum L.) in a recirculating aquaponic set up. The experiment was carried out on randomized block design and comprised four fish densities (0, 150, 250 and 500 fish m-3) and two crops, in which each treatment was continued for 45 days and replicated three times. Except for pH and total alkalinity, all water physicochemical parameters were increased significantly at high fish densities. In contrast, most of the biological parameters for fish were unaffected by culture density, although at the highest density crude protein percentage was significantly increased and ether extract percentage was significantly reduced. Plant productivities were highest when fish were cultured at density of 500 fish m-3, a density that was found to be appropriate for maintaining water quality and promoting fish growth while preventing toxicity and mortality. The present study has demonstrated the technical viability of coupling Nile tilapia culture coup with aquaponic production of marjoram and sweet basil.

The present study examined the effect of adding the antioxidants vitamins C and E on the quality of semen cryopreserved of curimba (Prochilodus lineatus). Semen samples from nine breeding males were collected for analysis of rate (%) and duration (s) of sperm motility. The sperm pool was diluted into three cryoprotective solutions: Solution A: 5 gr. Beltsville Thawing Solution (BTS) added with 5 mL dimethyl sulfoxide (DMSO) and distilled water to 100 mL; Solution B: Solution A + 0.0001 mg vitamin E; Solution C: Solution A + 0.0001 mg vitamin C. The vitamins C and E were not toxic to the semen of curimba. The sperm motility did not present any significant difference. However, the semen cryopreserved with vitamin C had a longer duration of the motility after thawing. Therefore, the vitamin C is recommended for the cryopreservation of the semen of curimba.