Evaluation of the acute toxicity of Thymus linearis ethanol extract and its effect on the hemato-biochemical and behavioural response of the Golden mahseer, Tor putitora (Hamilton, 1923).

The present investigation was conducted to estimate the acute toxicity of Thymus linearis plant extract, its effect on hemato-biochemical parameters and behavioural response in the golden mahseer (Tor putitora). The phytochemical composition present in T. linearis plant extrat were Alkaloids, Flavonoids, Phenols and Tannin. The fishes were subjected to eight different concentrations of T. linearis leaves extract (8.25, 8.50, 8.75, 9.00, 9.25, 9.50 and 9.75 mg/kg) and the control group without plant extract for 96-h LD50 study. The mortality was recorded every 24 h post-treatment. Minimum mortality was recorded in the 8.25 mg/kg, whereas 100% mortality was recorded in the 9.75 mg/kg T. linearis extract after 96-h periods. The LD50 was estimated by probit analysis, and the value of T. linearis at 96 h was found to be 8.71 mg/kg for golden mahseer. A non-lethal dose of 1/10th of 96-h LD50 value (0.87 mg/kg) was taken for the sublethal study. After 96 h, the red blood cell (RBC), white blood cell (WBC), haemoglobin (Hb), packed cell volume (PCV) and blood glucose were measured. RBC (×106/mm3), Hb (%) and PCV (%) significantly decreased at 8.25, 8.50, 8.75, 9.00 mg/kg, but WBC and blood glucose significantly increase at 8.25, 8.50, 8.75, 9.00 mg/kg of T. linearis plant extract. The observations on behaviour response of golden mahseer were also recorded. In the present study, the acute toxicity of wild ajwain was more significant than short-term toxicity. The mortality rate was very high during the study period of T. linearis exposure.

Factors influencing distribution patterns of cyanobacteria in an upland lake of the Kumaun Himalayas, India.

We study the dynamics of bloom-forming cyanobacteria and determined the major driving forces in subtropical lake of the Kumaun Himalayas, India. Water and plankton samples from different sites and depths of the lake were analyzed. Multivariate analyses were used to evaluate the factors controlling the distribution pattern of cyanobacteria. M. aeruginosa was the most abundant species with an average density of 10.39 × 106 individual/m3 and distributed throughout water depths. The geomorphic threshold modulates soil erosion processes resulting in lower transparency in the Himalayan lake; thereby limiting the growth of Chlorophycea. Effective persistence for M. aeroginosa into different depths is augmented by fluxes nutrient coupling with pigments. The ratio of nitrogen/phosphorus (N/P) had a significant negative correlation (F =-0.884; p = 0.0001) with densities. Expansion of M. aeruginosa in deep de-stratified lake is episodic and their proliferation can restrict by lowering phosphorus.