Paper Title
Haematological and Erythropoietic Parameters of Labeo Rohita(Hamilton, 1822) Experimentally Parasitized with Argulus Bengalensis (Ramakrishna, 1951)

Abstract
Infectious and non-infectious diseases are the major concerns whichcause potential negative impacts on fish production. Among the parasitic diseases, argulos is caused by the branchiuran genusArgulus results large scale economic loss to Indian aquaculture. Haematophagy of the parasite leads to acute hemorrhagic stress, retarded growth, secondary infection and mortality. The present study describes the alterations in the erythrocytic and erythropoieticparameters in Labeo rohita following an infection withArgulusbengalensis in amicrocosmexperiment. Significant alterations in blood parameters were observed throughout an infection period of 9 days. Significant changes in peripheral blood parametersindicated circulatory deterioration and development of oligocythemic macrocytic hypochromic anaemia in the infected fish.Furthermore, alterations in erythropoietin (EPO) level in both plasma and pronephric kidney of the experimental fish has been correlated with hypoxia induced erythropoiesis. The erythropoietic performance of the pronephric kidney throughout the infection period of 9 daysproved significant variations in relative abundance of the cells in erythropoietic lineage. Physiological implications of such erythrocytic and erythropoietic variations in relation to erythropoietin expression have been interpreted.The overall experimental result revealed that the rate of erythropoiesis is inadequate to compensate the acute and consistent loss of blood caused by the blood feeding activity of the parasites.Anaemia developed due to haematophagy of the parasite is identified as the principal cause of mass scale mortality of fish.