Books by Sandipan Gupta
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Book Chapter by Sandipan Gupta
Diversification of Aquaculture, 2012
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Papers by Sandipan Gupta
Ecological Indicators, 2019
Information on various aspects of reproductive traits of female pool barbs from various stretches... more Information on various aspects of reproductive traits of female pool barbs from various stretches of Ganga River basin, India was generated in relation to climatic variability. The presumptions surrounding – minnows being the first and easily hit by climatic variability, was validated. GAM models revealed low threshold rainfall requirement (>50 mm) within a wide temperature range (20–30 °C) necessary for attainment of breeding GSI (>10.5 units). Pre-spawning fitness (Kspawn50) and size at 50% maturity (LM50) benchmarked through Kaplan-Meier survival estimates were in the range 1.61–1.67 units (Fulton condition factor) and 8.6–9.0 cm respectively. Mapping of climate preferendum through LOESS smoothing hinted both low-mild rainfall (50–150 mm) and high rainfall conditions (400–700 mm) conducive for attaining pre-spawning fitness while no dependence on temperature was observed. First maturity of females was encountered at 4.7 cm within the size range 4.4–12.6 cm. The present study hinted a probable reduction (1.4–1.8 cm) in size at maturity of female pool barbs. We observed pool barbs can breed within a wide thermal regime following slightest of rainfall events. Collating this with the present rates of climatic variability, we infer negligible threat of changing climate on reproduction of Puntius sophore in near future – contrary to the existing presumptions. Owing to the easiness in attainment of pre-spawning fitness under an apparently flexible climate preferendum, ‘skipped spawning’ decisions while facing climatic variability also seem minimum. The recorded breeding thresholds may serve as future references while assessing climate driven changes on reproduction and evolutionary adaptations in Gangetic minnows.
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Environmental Biology of Fishes, Jan 18, 2018
Temperature and seasonal rainfall along with other environmental variables are important in regul... more Temperature and seasonal rainfall along with other environmental variables are important in regulating the reproductive cycles in teleost fishes. Certain environmental variables may act as cues for reproduction and changes in these may affect seasonality and success of reproduction, as fishes are known to integrate their physiological functions with environmental cycles. Wetlands are sensitive to climate change due to their shallow and confined nature. Since wetlands are important spawning and nursery grounds for many fishes, changes in the environmental variables may have direct consequences for the spawning and survival of fish. In the present study, we have assessed climatic and water chemistry variables capable of influencing seasonality in environmental variables as well as gonadal maturation of spotted snakehead Channa punctata, to predict threshold values of Gonado Somatic Index in females and a favourable range of identified climatic and water chemistry variables for breeding success. Among the climatic and water chemistry variables studied, seasonal variation in rainfall was found to have the most profound effect on gonadal maturation and breeding in C. punctata, followed by water temperature. The favourable range of rainfall obtained varied between 800 mm to 1400 mm, corresponding to the water temperature range between 29 °C and 31 °C. An overall significant warming trend with a reduction in total rainfall has been observed with changes in seasonal trends in temperature and rainfall in the study area. The rainfall being the major climatic factors influencing water chemistry in the wetlands during the spawning season, changes in rainfall pattern may influence breeding periodicity of C. punctata in wetlands in climate change scenario.
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The concept of threshold condition factor (Fulton), beyond which more than 50% of the female fish... more The concept of threshold condition factor (Fulton), beyond which more than 50% of the female fish population may attain readiness for spawning coined as pre-spawning fitness (Kspawn50), has been proposed in the present article and has been estimated by applying the non-parametric Kaplan-Meier method for fitting survival function. A binary coding strategy of gonadal maturity stages was used to classify whether a female fish is “ready to spawn” or not. The proposed Kspawn50 has been generated for female Mystus tengara (1.13–1.21 units), M. cavasius (0.846–0.945 units), and Eutropiichthys vacha (0.716–0.799 units). Information on the range of egg parameters (fecundity, egg weight, egg diameter) expected at the pre-spawning stage was also generated. Additional information on species-specific thermal and precipitation window (climate preferendum) within which Kspawn50 is attained was also generated through the LOESS smoothing technique. Water temperatures between 31 and 36 °C (M. tengara), 30 and 32 °C (M. cavasius), and 29.5 and 31 °C (E. vacha) and monthly rainfall between 200 and 325 mm (M. tengara), > 250 mm (M. cavasius), and around 50 mm and between 350 and 850 mm (E. vacha) were found to be optimum for attainment of Kspawn50. The importance of parameterization and benchmarking of Kspawn50 in addition to other conventional reproductive biology parameters has been discussed in the present article. The purposes of the present study were fulfilled by generating baseline information and similar information may be generated for other species replicating the innovative methodology used in this study.
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99 taxa of avifauna belonging to 43 families has been recorded in successive years (2013 and 2014... more 99 taxa of avifauna belonging to 43 families has been recorded in successive years (2013 and 2014) in a seasonal survey
carried out at Jaldapara National Park located within Himalayan Terai region of North Bengal. The open forest habitat found out to be the richest in avifauna among the other habitat types. Among the feeding guilds, insectivores dominate in species strength and in the number habitat types represented. Survey shows that the landscape of Jaldapara is frequently visited by 2 Vulnerable (Lesser Adjutant and Pallas's Fish Eagle) and 1 Near Threatened species (River Lapwing). The study documented Kalij Pheasnat which is probably new record from this region.
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Books by Sandipan Gupta
Book Chapter by Sandipan Gupta
Papers by Sandipan Gupta
carried out at Jaldapara National Park located within Himalayan Terai region of North Bengal. The open forest habitat found out to be the richest in avifauna among the other habitat types. Among the feeding guilds, insectivores dominate in species strength and in the number habitat types represented. Survey shows that the landscape of Jaldapara is frequently visited by 2 Vulnerable (Lesser Adjutant and Pallas's Fish Eagle) and 1 Near Threatened species (River Lapwing). The study documented Kalij Pheasnat which is probably new record from this region.
carried out at Jaldapara National Park located within Himalayan Terai region of North Bengal. The open forest habitat found out to be the richest in avifauna among the other habitat types. Among the feeding guilds, insectivores dominate in species strength and in the number habitat types represented. Survey shows that the landscape of Jaldapara is frequently visited by 2 Vulnerable (Lesser Adjutant and Pallas's Fish Eagle) and 1 Near Threatened species (River Lapwing). The study documented Kalij Pheasnat which is probably new record from this region.