Piscicidal plants of Northeast India and its future prospect in aquaculture - A comprehensive review

165-174Traditional knowledge and some indigenous techniques still serve as a reliable tool for harvesting resources from nature. Different species of plants (approx. 114) are used as piscicides by various people inhabiting Northeast India from a long period of time for fish harvesting purpose. The principle bioactive compounds present in the plant part (leaves, seed, kernels & bark) have varying potencies and mode of action depending on whether it is applied directly or in the forms of extracts (aqueous & alcohol) used. Aquaculture is one of the major sources of livelihood and protein in Northeast India. Although rich numbers of piscicidal plants are available, it cannot be commercially utilized in aquaculture unless detailed accounts of these plants are known. Bioactive compounds like saponins, rotenone, tannins, alkaloids etc. present in the plant may help to control the unwanted/predatory fish for healthy aquaculture. In the present review, the focus is given to all the plants used as a piscicide in Northeast India and its bioactive compounds, extraction medium, effective dose, test fish species and their biochemical, physiological and behavioural changes on some commercially important fish in India. Uses of herbal piscicides in aquaculture may help in replacing the harmful chemical piscicides of the environment

Piscicidal plants of Northeast India and its future prospect in aquaculture - A comprehensive review

Traditional knowledge and some indigenous techniques still serve as a reliable tool for harvesting resources from nature. Different species of plants (approx. 114) are used as piscicides by various people inhabiting Northeast India from a long period of time for fish harvesting purpose. The principle bioactive compounds present in the plant part (leaves, seed, kernels & bark) have varying potencies and mode of action depending on whether it is applied directly or in the forms of extracts (aqueous & alcohol) used. Aquaculture is one of the major sources of livelihood and protein in Northeast India. Although rich numbers of piscicidal plants are available, it cannot be commercially utilized in aquaculture unless detailed accounts of these plants are known. Bioactive compounds like saponins, rotenone, tannins, alkaloids etc. present in the plant may help to control the unwanted/predatory fish for healthy aquaculture. In the present review, the focus is given to all the plants used as a piscicide in Northeast India and its bioactive compounds, extraction medium, effective dose, test fish species and their biochemical, physiological and behavioural changes on some commercially important fish in India. Uses of herbal piscicides in aquaculture may help in replacing the harmful chemical piscicides of the environment

Delineation of seven species of genus Channa from upper Assam region, India using sagittal otolith morphology

Morphology of sagittal otoliths of seven species of genus Channa from upper Assam, India was studied to obtain baseline information for their prospective role in taxonomic studies. In the present study, variations were recorded in morphological characteristics of sagittal otolith among the studied species. Of all the studied parameters, otolith shape, sulcus acusticus, ostium, and cauda, in particular, were found to be taxonomically important features for the identification of the species. The pentagonal shape of sagitta in Channa punctata, pseudo-ostiocaudal sulcus acusticus in C. marulius, bent concave ostium in C. stewartii, straight cauda in C. bleheri were found to be species-specific features. Sagitta size was smallest in C. gachua while the largest was recorded in C. striata. The proposed taxonomic keys enumerated through the combination of different otolith characters from the present investigation will be useful in the identification of these species when standard methodologies fail to deliver satisfactory results

<span style="font-size:11.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-GB">Physiological responses of <i style="mso-bidi-font-style:normal">Catla catla</i> larvae fed with <i>Achyranthes aspera</i> seed enriched diet and exposed to UV-B radiation</span>

155-160The antioxidant and growth stimulating properties of seeds of Achyranthes aspera were evaluated on UV-B irradiated Catla catla (catla) larvae. Catla larvae (initial weight: 1.2 ± 0.01 mg) were fed with four different diets — D1, D2 and D3 containing 0.1, 0.25 and 0.5% seeds of <i style="mso-bidi-font-style: normal">A. aspera and D4, control diet for 35 days. The larvae were then exposed to UV-B radiation (80 µW/cm2) on every alternate day for 20 days. Survival, growth, tissue glutamic oxaloacetic transminase (GOT), tissue glutamate pyruvate transminase (GPT), thiobarbituric acid reactive substances (TBARS) and nitric oxide synthase (NOS) were studied in larvae on day-21 of irradiation. Significantly (P < 0.05) higher survival and average weight were found in D3 diet fed fish compared to the other groups. Survival rate was 8-16% higher in seed enriched diet fed groups, compared to the control one. Higher levels of GOT and GPT found in control diet fed larvae showed the degree of tissue damage due to UV-B exposure. Significantly (P 0.05) lower level of GPT in D3 indicated the UV-B protective effect of the seed of A. Aspera (earlier, the presence of ecdysterone, essential fatty acids and amino acids, polyphenolic compounds, steroids, etc. has been reported from seed). TBARS which indicated the level of tissue lipid peroxidation were significantly (<i style="mso-bidi-font-style: normal">P 0.05) higher in control group, compared to the other feeding schemes. NOS level was significantly (P 0.05) higher in D2 and D3, compared to the D1 and control groups. In conclusion, supplementation of A. aspera seed (0.5%) improved the physiological condition (in terms of reduce lipid oxidation and better immune system) and gave bioprotection to catla larvae challenged with UV-B stress