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To explore the feasibility of land-based farming on mackerel tuna (Euthynnus affinis), the changes of antioxidant, immune and digestive enzyme activities of wild caught and indoor cultured juvenile mackerel tuna were evaluated. The activities of total superoxide dismutase, catalase, peroxidase and alkaline phosphatase in the liver of the wild group were significantly higher than those cultured under captivity. The total superoxide dismutase and peroxidase activities in the indoor cultured group were significantly increased in the head kidney, and the MDA content was significantly increased. The activities of lysozyme in the liver and head kidney, the activities of amylase, lipase and trypsin activities in the intestine were significantly increased in the indoor cultured group. The pepsin activity in the stomach was significantly reduced. The land-based farming increased the digestive enzyme activity compared to the wild caught group. The mode of land-based farming is suitable for growth and fattening of young fish, but it leads to inhibition of antioxidant capacity and increase in immune enzyme activity. This study adds knowledge of our understanding on the physiological response of mackerel tuna and improves future farming practice of this species in an indoor condition. [ABSTRACT FROM AUTHOR]

This study investigated the reproductive capacity of pond-reared female Penaeus monodon after unilateral eyestalk ablation. A total of 240 females (57.0-143.3g) were used as broodstocks in a continuous threeyear breeding experiment. After unilateral eyestalk ablation, the relationships of egg and nauplii at the first spawning event and female bodyweight were evaluated. At each spawning, a female could produce 120000-1250000 eggs which hatched into 80,000-950,000 nauplii. The egg hatching rate at each spawning varied from 27.4% to 86.3% without particular patterns of correlation with female body weight. The fecundity of pond-reared female P. monodon varied from 2 100 to 9 400 eggs per gram of bodyweight, and females with medium size of 85-120 g showed greater fecundity (around 9000 eggs/g) in comparison with smaller and larger counterparts. This study indicates that reproductive capacity of pond-reared female P. monodon is significantly related to bodyweight with a desirable size of 85-120 g as female broodstocks. [ABSTRACT FROM AUTHOR]

Skeletal anomalies in farmed fish affect animal welfare and economic return in aquaculture but very limited information exists on skeletal ontogeny and anomalies among species of the family Lutjanidae. This study describes the skeletal ontogeny and anomalies of crimson snapper Lutjanus erythropterus larvae and juveniles from hatching to 36 day-post hatching (DPH). Mandible, ceratobranchial, cleithrum and gill arches were the initial skeletal structures appeared at 3 DPH that supported the vital life functions such as feeding and respiration. Ossification of premaxilla and maxilla and dentary started at 3.21 ± 0.25 mm (9 DPH), and completed at 5.91 ± 0.34 mm (18 DPH). The head skeleton formation completed at 22.35 ± 2.26 mm (31 DPH). The axial skeleton development started with the formation of neural arches at 3.64 ± 0.07 mm (10 DPH) and ossification of axial skeleton completed at 11.01 ± 0.88 mm (24 DPH). The fins developed sequentially and the ossification of fins completed at 30.57 ± 2.44 mm (36 DPH). A total of 39.5% fish exhibited anomalies in the present study and the anomalies were: lordosis, vertebral fusion, neural spines bifurcation, connection of adjacent pterygiophores, haemal spine anomaly, neural spines anomaly, anomaly in pterygiophores and supernumerary neural spines. Results from this study add new knowledge to functional morphology of crimson snapper that would be useful to larval aquaculture of marine teleosts. [ABSTRACT FROM AUTHOR]

The requirements of micronutrients for biomass and hydrocarbon production in Botryococcus braunii UTEX 572 were studied using response surface methodology. The concentrations of four micronutrients (iron, manganese, molybdenum, and nickel) were manipulated to achieve the best performance of B. braunii in laboratory conditions. The responses of algal biomass and hydrocarbon to the concentration variations of the four micronutrients were estimated by a second order quadratic regression model. Genetic algorithm calculations showed that the optimal level of micronutrients for algal biomass were 0.266 μM iron, 0.707 μM manganese, 0.624 μM molybdenum and 3.38 μM nickel. The maximum hydrocarbon content could be achieved when the culture media contained 10.43 μM iron, 6.53 μM manganese, 0.012 μM molybdenum and 1.73 μM nickel. The validation through an independent test in a photobioreactor suggests that the modified media with optimised concentrations of trace elements can increase algal biomass by 34.5% and hydrocarbon by 27.4%. This study indicates that micronutrients play significant roles in regulating algal growth and hydrocarbon production, and the response surface methodology can be used to optimise the composition of culture medium in algal culture. [ABSTRACT FROM AUTHOR]