Effects of phenanthrene on hepatic enzymatic activities in tilapia(Oreochromis niloticus ♀×O.aureus ♂)

The effects of phenanthrene（Phe） on hepatosomatic index（HSI） and hepatic enzymatic activities in hybrid tilapia（Oreochromis niloticus ♀× O.aureus ♂） were investigated via the static freshwater exposure at dosage of 50,100,and 400 μg/L for 4-14 d.Compared with the control group,HSI was significantly decreased（P 〈 0.05） at 400 μg/L at day 14.Increased enzymatic activities（P 〈 0.05） were observed for catalase（CAT）,glutathione peroxidase（GPx） and superoxide dismutase（SOD） at either 100 or 400 μg/L at day 8 and 14,as well as for CAT at 50 μg/L at day 14,except for GPx at 400 μg/L at day 8.Ethoxyresorufin O-deethylase（EROD） activity was significantly increased（P 〈 0.05） at all dosage at day 4 as well as at 50 μg/L at day 8,but significantly decreased at either 100 or 400 μg/L at day 14（P 〈 0.05）.Glutathione-S-transferase（GST） activity was not affected.The results suggest that CAT,GPx,SOD and EROD,as well as HSI in tilapia may be used as the biomarkers or indexes for evaluating or monitoring the pollution of polycyclic aromatic hydrocarbons（PAHs） such as Phe.

Effect of BEDGEN 40 on Growth, Anti-Oxidant Activity and Resistance against Aeromonas Hydrophila Infection in Tilapia （Oreochromis niloticus x O. aureus）

The globe artichoke has become important as a medicinal herb in recent years following the discovery of cynarin. This bitter-tasting compound, which is found in the leaves, improves liver and gall bladder function, stimulates the secretion of digestive juices, especially bile, and lowers blood cholesterol levels. The leaves are anticholesterolemic, antirheumatic, cholagogue, digestive, diuretic, hypoglycaemic and lithontripic. BEDGEN 40 , a compound made with Cynara scolymus L. （artichoke） extract and choline chloride was evaluated for growth performance and anti-oxidant activity in tilapia. There were four treatment groups; group 1 was fed only with a basal diet and served as the control, group 2 - 4 were experimental groups that received 150, 300, or 600 mg/kg BEDGEN 40 , respectively, added to the basal diet and fed for 8 weeks. The results showed signifi- cant differences for weight gain, feed conversion, and protein efficiency in fish diets containing 150, 300, or 600 mg/kg BEDGEN 40 compared to the control. Generally, BEDGEN 40 improved the body condition factor and hepatosomatic index of tilapia, and reduced liver fat content. Fish consum- ing BEDGEN 40 also exhibited improved liver antioxidant status. BEDGEN 40 （300, or 600 mg/kg） was also found to significantly reduce the mortality of tilapia subsequently challenged with Aeromonas hydrophila.

四种罗非鱼精子超微结构的比较

借助扫描电镜和透射电镜对尼罗罗非鱼（Oreochromis niloticus）、奥利亚罗非鱼（O.aureus）、奥尼罗非鱼（O.niloticus×O.aureus）和吉富罗非鱼（GIFT Strain in Nile Tilapia,O.niloticus）成熟精子的超微结构进行了比较研究。结果显示,4种罗非鱼精子均为有鞭毛精子,无顶体,尾部轴丝9±2型。尼罗罗非鱼精子植入窝陷入核深度最浅,线粒体个数和平均直径分别为5-9个、（0.36±0.10）μm,鞭毛侧鳍平均翼长为（0.29±0.11）μm;奥利亚罗非鱼精子核内染色质着色程度最深,植入窝陷入核深度约1/3,线粒体个数和平均直径分别为3-10个、（0.40±0.17）μm,鞭毛侧鳍平均翼长为（0.32±0.12）μm;奥尼罗非鱼精子核内染色质着色程度较浅,植入窝陷入核深度约1/3,线粒体个数和平均直径分别为5-7个、（0.32±0.09）μm,鞭毛侧鳍平均翼长（0.26±0.09）μm;吉富罗非鱼精子核内染色质着色最浅,植入窝陷入核最深,约占2/3,线粒体个数和平均直径分别为5-10个、（0.37±0.08）μm,中段存在大量中空囊泡,鞭毛侧鳍平均翼长为（0.15±0.03）μm,与其它三种罗非鱼精子鞭毛平均侧鳍翼长比较具显著性差异（P〈0.05）。