الفهرس 
INTRODUCTION
The African catfishOnly 14 pages are availabe for public view
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Abstract
Aquaculture represents one of the fast growing food producing sectors of the world and aims to increase productivity per unit space. Among various kinds of cultivated organisms, many marine and freshwater finfish and shellfish species constitute an important industry with their production increasing every year. Recently, due to intensive farming practices, infectious diseases pose a major problem in aquaculture industry, causing heavy loss to farmers. In order to address this problem, several studies have been conducted on the modulation of fish immune system in order to prevent the outbreak.
With the increasing demand for fish as human foods, fish farming both in fresh water and salt water are rapidly expanding all over the world especially in developing countries including Egypt to compensate the deficiency in animal protein.
The use of immunostimulants in aquaculture for prevention of diseases is a promising new development. The field of essential metalloelement complexes has attracted many authors in the last decade.
The present study was conducted to evaluate the efficiency of the copper chelating complex in improving the immune response, survival and disease resistance in catfish (Claris gariepinus.) in comparisons with other common immunostimulant (Garlic, Nigella sativa and Livamizol ).
Hundred african sharptooth catfish, Clarias gariepinus, with a range of body weight 100-120 g, and length 20- 25 cm were obtained from a private fish farm at Assiut governorate and transported alive to laboratory at the farm of the Faculty of Agriculture, Assiut University, Assiut, Egypt. After acclimatization for 20 days, divided randomly into five groups (20 fish each group), the first group (control group) received the basic diet, for 30 days. The second group received the basal diet mixed with copper chelating complex 60 mg /kg basal diet, the third group received the nigella sativa 3% mixed diet, while the fourth group received the diet mixed with livamizol 225mg/ kg. The fifth group received the basic diet mixed with the 4% minced garlic.
Each group had 20 fish and was fed with only one diet variant twice daily with 3% of the life body for 30 successive days. At the end of 30 days feeding, all fish of each group were weight, blood samples were taken from 5 fishes of each group and blood smears were taken, Serum were collected for biochemical parameters. All types of leucocytes were distinguished and characterized by light microscopy and a mean relative percent calculated. Serum total proteins, albumin and globulin were determined and calculated. All fish in each group were injected intrapretonially by 1.5 x10 CFU /ml of Aeromonas hydrophila, and the clinical signs, post mortem lesions and mortalities were monitored for 7 days post challenge.
The significant higher body weight was observed in all treated groups comparison with the fish of the control group, while no significant difference in between the treated group (GII – GV).
The total protein and the globulin value in the serum of fish fed with copper albumin chelate as well as in the groups fed with levamisol, nigella sativa and minced garlic were high in comparison with the group fed on basal diet. The survival rate after challenge with aeromonas hydrophlia were 100% in the group of fish fed with copper chelating complex compared with 65 % in the fish of the control group. Statistically no significant difference was observed in lymphocyte values obtained in the blood films taken from the fish of the (GI) feeding with basal diet was 63.00% while the highest percentage of the lymphocytes was in fish of the GII (67.600 %( that fed on copper albumen chelate mixed diet with no significant difference between all treated groups (GIII fed with nigella sativa mixed diet 66.800 %, G IV fed with livamisol mixed diet 60.00 % and GV fed with garlic mixed diet 63.8%).
The % of monocytes of fish group fed on copper chelateing complex diet was high (24.40±1.36 %)in comparison with the control group (18.00±3.52%).
Monocytes percent obtained in the control group (18.00 %) and the in the group II fed with copper chelating complex mixed diet was (13, 60 %) as well as in the other groups that fed with other immunostimulants nigella sativa, livamisol and garlic 13.80%, 12, 40% and 12.00 % respectively. The percent of neutrophil was 9.20% in the control group compared with 12.0% in the group fed copper chelating complex mixed diet, while in the group fed with nigella sativa, levamisol and minced garlic were 8.8%, 9.2% and 9.2% respectively
The percent of basophile was 2 % in the control group and 4% in the second group compared with 3% in the groups III, IV, V
The percent of eosinophils was 2% in the control group as well as in the group II and III, while in the groups IV and V was 3%.
The observed increase of lymphocytes and basophil in fish kept on copper chelatng complex mixed diet may be attributed to the activation of lymphoid tissue.
Copper chelating complex perhaps stimulate the haemopiotic tissues not less than the other immunostimulants used as feed additive and subsequently led to production of extensive number of effective functional cells as a defense mechanism.
The higher globulin in serum of fish fed copper chelating complex mixed diet indicate that activation of the humoral response against the A. hydrophila infection and this response reflected in 100% survival rate after the challenge test with Aeromonas hydrophila. .
from the presented results, use of copper chelating complex as feed additive for Claris gariepinus at a dose of 60mg / kg diet for one month has shown to be an activator of nonspecific innate immune response.
Copper chelating complex as feed additive for Claris gariepinus at a dose of 60mg / kg of diet for one month has a more protective effect than the other immunstimulant against the infection with the Aeromonas hydrophila.