STUDIES ON LERNAEOSIS AMONG CULTURED COMMON CARP (CYPRINUS CARPIO) WITH SPECIAL REFERENCE TO ITS PREVENTION BY VACCINATION

Osama A. Saleh; Ahmed M. Abel-Wahab

and Ahmed M.M. El-Ashram

Fish Diseases Department, Central Lab. For Aquaculture Research, Abbassa, Agriculture Research Center

Received 1/ 4/ 2010

Accepted 30/ 4/ 2010

Abstract

A total number of two hundreds common carp (Cyprinus carpio) naturally infested with Lernea cyprinacea were collected a live or freshly dead and subjected to clinical signs, parasitological and pathological examinations. Heavily infested fish showed increased of mucus secretions, ulceration and rubbed their bodies against hard objects. Intensity of adult Lernea was ranged from 1 to 176 per fish. The light, moderate, heavy and extreme infestation rate was 7.5, 15, 40 and 37.5%, respectively. Fins were the most preferable site for infestation. Histopathologically, sloughing of most superficial layers of epidermis with edema and leukocytic infiltration. A hundred of common carp were divided into four equal groups and injected with L. cyprincea antigen at concentration of 10, 20, 30 and 0 µg proteins per gm fish, respectively. Poster dose was injected at the same concentration after two weeks of the first one. All fish groups were exposed to natural infestation by adding five heavy naturally infested common carp. The PVC values were significantly higher in the treated groups than control. Also, a significant protection was achieved by injection of L. cyprincea antigen. The infestation rates were 52, 12, 16 and 96% among the immunized groups and control one, respectively. The detection of
specific antibodies was confirmed by agar gel precipitation test. Forty naturally infested common carp fingerlings were equally divided into 4 equal groups and injected by the collected serum from the second immunized group i/m at a dose of 0.1, 0.2, 0.3 ml, respectively. The fourth group was being designated as non-treated control group. The recovery rate from infestation was recorded. The recovery rates were 40, 60, 80 and 10%, respectively. Also, forty healthy common carp fingerlings were equally divided into four groups and inoculated with immunized serum at the same concentrations as previously mentioned. All of them were exposed to natural infestation as mentioned before. The infestation rates were 50, 20, and 10% respectively among the injected groups at 0.1, 0.2 and 0.3ml compared with 90% for control. Further research and testing of vaccine in other fish species and under field conditions is indicated.