A study of physico-chemical characteristics of lakes around Jaipur, India.

Annual survey of Jalmahal, Amer, Nevta and Ramgarh lakes, has been conducted for one calendar year, to determine physico- chemical characteristics of water and the levels of zinc (heavy metal) and endosulfan (an organochlorine pesticide). These lakes are situated on the outskirts of Jaipur city. Changes in pollutants correlated well with the physico-chemical characteristics of water bodies. Results reveal that the levels of endosulfan and zinc are highest in Jalmahal lake (1.324 and 0.197 mg l-1 respectively) and lowest in Ramgarh lake (0.020 and 0.120 mg l-1 respectively). Anthropogenic sources and cultivation in the dried up area of these lakes seem to contribute largely to pollution.

Alterations in biochemical profile of liver and ovary in zinc-exposed fresh water murrel, Channa punctatus (Bloch).

Sub-chronic exposure (15 days) of Channa punctatus to sub-lethal concentrations of zinc (10, 15 and 25 Zn mg l-1) resulted in a significant decline of hepatic and ovarian glycogen, cholesterol, total proteins and total lipids. DNA and RNA contents were also estimated in the ovary. These parameters simultaneously decline with an increase in dose and duration of the experiment. A decline in all parameters studied thus reflects an adverse influence of Zn exposure on metabolism as well as reproductive activity of the fish.

Changes in nutritive value of fish, Channa punctatus after chronic exposure to zinc.

The present investigation was undertaken to assess the effects of sublethal concentrations of zinc (0.1 and 0.2 mgl(-1)) on the nutritional value of fish Channa punctatus after exposure for 135 days. The parameters studied were, levels of total proteins, glycogen, total lipids, cholesterol and vitamins (A and D) in the muscle. Total proteins, glycogen, total lipids and vitamin D show highly significant decline from day 90 to 135, while cholesterol and vitamin A, show no significant changes upto 105 days. This study signifies a drastic reduction in the nutritive value of fish, which is compounded by the fact that under natural conditions fish are exposed to these levels of zinc for prolonged periods.

Haematological response of fish Channa punctatus (Bloch) to chronic zinc exposure.

Sub-lethal concentrations of zinc administered to freshwater teleost, Channa punctatus for a period of 135 days brought about significant haematological alterations. The RBC count, haemoglobin and haematocrit content progressively decreased while WBC count, MCV, MCH and MCHC increased. Alterations in the haematological parameters were dose and duration dependent and can thus serve as a useful physiological index.

Study of physico-chemical characteristics of water bodies around Jaipur.

The present study has been undertaken to evaluate physico-chemical parameters (pH, temperature, dissolved oxygen, free carbon dioxide, alkalinity and hardness) and zinc concentration in water bodies in and around Jaipur. Water samples from Jalmachal Lake, Nevta Lake, Amer Lake and Ramgarh Lake were analysed. Results reveal that the water of Jalmahal Lake is most polluted due to high pH, hardness, alkalinity, free carbon dioxide, zinc content, and a low level of dissolved oxygen. Contrarily Ramgarh Lake is least polluted, as it has high dissolved oxygen and low pH, alkalinity, free carbon dioxide, hardness and zinc content.