Roles of natural zeolite (clinoptiolite) as a bed medium on growth and body composition of red tilapia (Oreochromis sp.) and lettuce (Lactuca sativa var longifolia) seedlings in a pisciponic system

Natural zeolite was used as a bed medium for plantation of lettuce seedlings and its effects on growth and chemical composition of red tilapia and lettuce were investigated in a pisciponic system. The place of study was the Aquatic Resources Technology Laboratory, Faculty of Agriculture, at the University Putra Malaysia, in 2002. The mean individual weight and biomass of fish in the treatment with zeolite were significantly higher (P0.05) between treatments. The percentage of ash in the dry weight of lettuce in the control was significantly (P<0.05) higher than the zeolite bed medium group. It was concluded that the use of zeolite as bed medium to plant lettuce seedlings could improve culture system performance due to its positive effects in lettuce growth

Study of changes in macro elements Ca, Mg, Na and K in eggs of rainbow trout (Oncorhynchus mykiss) at different incubation stages

We studied rainbow trout eggs requirements to macro elements Ca, Mg, Na and K at different stages of incubation period. The research was carried out at Namroud rainbow trout hatchery center in winter 2005. Two incubators in equal conditions were selected. The first was stocked with approximately 60000 eggs and the second had no eggs. A total of 100 fertilized eggs were sampled and assessed for the elements before introduction of the eggs to the incubator. Weekly samples were taken from the eggs and water of the first and second incubator. The sampled eggs were digested by Tripathi method and concentration of the elements in eggs extract was measured by ICP apparatus. In addition, variation of these elements between input and discharge water of both incubators was investigated

The study of heavy metals Copper, Zinc, Iron and Manganese bioaccumulation in the eggs of rainbow trout (Oncorhynchus mykiss) during incubation period

The aims of the present study were to examine bioaccumulation of heavy metals copper, zinc, iron and manganese in rainbow trout eggs at different stages of incubation period and to compare the results with those of the EPA standards. The research was carried out at Firoozkooh Namroud Rainbow Trout Hatchery Center. For this purpose, two incubators with the same condition as experimental units were selected, one of them was the experimental incubator with approximately 60000 eggs and the other one had no eggs as the control. Sampling of eggs and water during incubation period was conducted weekly. The results showed significant differences (P<0.05) in the control incubator. This indicates that eggs have absorbed these elements from incubation water and then showed increasing trend for Zn and Fe elements concentration in dry weight egg extract during incubation stages but increasing trend in Mn and Cu elements went on until the third stage. The results indicate that threshold concentrations for Mn and Cu in egg cause egg resistance against more absorption of these elements. Also, the results showed that at all sampling stages, concentration of the studied elements was lower than EPA standards for animal textures

The effects of exposure to sub-lethal copper and cadmium concentrations on biochemical factors of one year old Persian sturgeon, Acipenser persicus

The aim of this study was to determine the 96h LC50 of copper and cadmium, and also, to evaluate the effects of their sub-lethal dose on stress factors in Persian sturgeon, Acipenser persicus. Obtained results from Probit analysis showed 96h LC50 values of 0.502 and 14.78mg/l for copper and cadmium, respectively. Also, in single sub-lethal exposures, 72 juveniles (130±19g) were exposed to 0.026 and 0.68mg/l of copper and cadmium in semi- static conditions, and some stress-related biochemical factors were assessed in 1, 7 and 14 days. According to the obtained results, plasma glucose and cortisol were increased (P0.05) differences in plasma and liver protein contents between experimental groups and controls with the exception of copper treatment at the first day of sampling when plasma protein contents showed significant increases, but decreased significantly (P<0.05) in the subsequent sampling stages. In addition, with copper treatment, significant decreases were observed in plasma triglyceride concentrations as time passed by compared to day 1 (P<0.05). Results showed that copper is more toxic than cadmium for this species and also, 96h LC50 of copper and cadmium are stressful for Persian sturgeon

Study of changes in macro elements Ca, Mg, Na and K in eggs of rainbow trout (Oncorhynchus mykiss) at different incubation stages

We studied rainbow trout eggs requirements to macro elements Ca, Mg, Na and K at different stages of incubation period. The research was carried out at Namroud rainbow trout hatchery center in winter 2005. Two incubators in equal conditions were selected. The first was stocked with approximately 60000 eggs and the second had no eggs. A total of 100 fertilized eggs were sampled and assessed for the elements before introduction of the eggs to the incubator. Weekly samples were taken from the eggs and water of the first and second incubator. The sampled eggs were digested by Tripathi method and concentration of the elements in eggs extract was measured by ICP apparatus. In addition, variation of these elements between input and discharge water of both incubators was investigated.Publishe

The study of heavy metals Copper, Zinc, Iron and Manganese bioaccumulation in the eggs of rainbow trout (Oncorhynchus mykiss) during incubation period

The aims of the present study were to examine bioaccumulation of heavy metals copper, zinc, iron and manganese in rainbow trout eggs at different stages of incubation period and to compare the results with those of the EPA standards. The research was carried out at Firoozkooh Namroud Rainbow Trout Hatchery Center. For this purpose, two incubators with the same condition as experimental units were selected, one of them was the experimental incubator with approximately 60000 eggs and the other one had no eggs as the control. Sampling of eggs and water during incubation period was conducted weekly. The results showed significant differences (P0.05) in the control incubator. This indicates that eggs have absorbed these elements from incubation water and then showed increasing trend for Zn and Fe elements concentration in dry weight egg extract during incubation stages but increasing trend in Mn and Cu elements went on until the third stage. The results indicate that threshold concentrations for Mn and Cu in egg cause egg resistance against more absorption of these elements. Also, the results showed that at all sampling stages, concentration of the studied elements was lower than EPA standards for animal textures.Publishe