فهرست مطالب roya rahnama

Lead (Pb) is an important metal used in industries, mining and agriculture. It is equally important to the aquatic ecosystems and has negative impact on the health of aquatic organisms.

The LC50 of lead toxicity at varying salinities was first determined for 96 hours. Then juvenile fish were transferred to tanks individually and were exposed to 0, 15, 30, 60 and 120 mg/l of Pb at varying salt concentration of 0, 0.1, 0.2 or 0.4 g/l. The blood samples were taken after the 4th day and the hematological parameters were evaluated. 

Red Blood Cells (RBC) and White Blood Cells (WBC) were decreased in almost all lead treated groups. The Hb levels decreased consistent with increasing lead concentrations (P<0.05). The mean corpuscular volume, hemoglobin and the concentration were not affected by the lead concentrations compared to those for the control group. The WBC and RBC counts showed an inverse correlation with the lead concentrations in the Pb-exposed fish. A direct correlation was also observed in the lead concentration and the heterophile rate (P<0.05). 

The results showed that salinity did not affect the hematological parameters, but the LC50 values decreased with increasing salinity.

Saprolegniosis is one of the most frequent diseases in the ornamental fish industry that may cause by Achlya spp. There is no report of fungal infection caused by Achlya spp. in Oscar (Astronotus ocellatus) in Iran. An Oscar fish was referred to the Veterinary Hospital, Shahid Chamran University of Ahvaz, Ahvaz, Iran with saprolegniosis symptoms including loss of appetite and yellow to gray cottony mass on the skinof flank and caudal peduncle. The infected area of the fish body was investigated by wet smear. After observing broad aseptate hyphae (approximate width 10-15 μm), the infected skin was inoculated on Sabouraud dextrose agar and incubated at 30 ˚C for seven days. The large fungi colony was appeared on the agar and the isolated fungi were detected as Achlya spp. after examination by wet and stained dry smears according to the morphology of hypha, spores, and zoosporangium. It is the first report of cutaneous saprolegniosis in Oscar caused by Achlya spp. in Iran.

Herbicides are widely used in agriculture to kill a large variety of unwanted weeds. However, the application in water ecosystems may pose harmful impacts on the health of aquatic organisms. We studied the acute toxicity of four major types of herbicides on the survival of adult shrimp, Artemia franciscana (AF). The brine shrimp, AF, was hatched from the commercially encysted dry eggs. The acute toxicity (LC50; 48 hr) of four herbicides, paraquat; 2,4-dichlorophenoxy acetic acid (2,4-DCPA); trifluralin; and glyphosate, was examined by a standard method. We exposed the shrimps to sequentially rising concentrations of each herbicide in triplicate. The mortalities were recorded at 12, 24, 36, and 48 hours after exposure and the LC50 was calculated, using a Probit software. This study demonstrated that the acute toxicity of these herbicides was significantly different in adult shrimp AF. The lethal concentrations (LC50) of Paraquat, 2,4-DCPA, trifluralin and glyphosate against the shrimp were 2.701, 14.475, 0.446 and 17.431 mg/l, respectively. Trifluralin and paraquat caused the highest lethality at lower LC50 concentration compared to the other two herbicides. The results demonstrated that increasing herbicides concentration or duration of exposure raised the mortality rate of AF’s

Control and preventing the spread of diseases in the farmed fish requires a regular monitoring, eradication or vaccination program. And in this respect, the serology as a monitoring and diagnostic tool can be very useful. In recent years, monoclonal antibodies have been considered a tool in immunological in immunological research. These anti-inflammatory drugs are highly specialized in epitopes and are prepared in large volumes. Due to their high purity, monoclonal antibodies act as standard chemical agents. They have been quickly being used in clinical diagnostic techniques since a lot of them are needed in the production of commercial kits. Like serology in other animals, serum testing in fish also requires the use of anti-antigens (anti-IgM). For the same reason, during the last decade, efforts have been made to produce anti-IgM antibodies for the production of monoclonal antibodies, suitable for each species of freshwater and marine fishes. Therefore, the production of these antibodies in the interior, in addition to the help and development of the rapid and accurate detection of marine fish diseases can lead to currency savings.