The aims of the research are to determine the hematological response of Java Barb which is exposed to heavy metal lead (Pb) at different doses. Water pollution occurs due to industrial activities that contain toxic materials which are increasing with the development of industrialization. One of the heavy metals that cause pollution in Sidoarjo, East Java Indonesia waters is lead (Pb). Heavy metal in waters at can affect the life of aquatic biota, especially fish. Lead (Pb) enter the body of an organism through the food chain, gills or diffusion through the surface of the skin.

Lead enters the fish cause toxic effect that increase in oxidative stress, organ damage and changes in the biochemical profile of the blood which indicates metabolism in the body is disturbed. Metabolic disorders will affect the growth of cultivated fish Java Barb (Barbonymus gonionotus), is one type of freshwater fish that is widely cultivated in Indonesia but is very sensitive to changes of water quality.

The research was an experimental using a completely randomized design consisting of 5 treatments and 4 replications. The treatment are differences in lead doses, namely A (0 ppm), B (0.66 ppm), C (1.32 ppm), D (1.98 ppm) and E (2.65 ppm). The parameters of observation were total erythrocytes, hemoglobin, total leukocytes and leukocytes differential, blood glucose and cortisol. Data obtained were analyzed using Anova to determine the effect of treatment. Differences between treatments were analyzed using Duncan's multiple distance test.

The results showed that distribution of different lead doses increase the number of leukocytes and reduce the total erythrocytes, hemoglobin hematocrit, leukocytes differential, blood glucose and cortisol.