RESUMO
The essential role of smaller streams and tributaries indigenous to the area is crucial in revitalizing and restoring the main river system. The present study unraveled the relationship between plankton communities and environmental variables in the Shipra River, a Central Himalayan tributary of the Kosi River in Uttarakhand, India. Plankton distribution, abundance, and presence were investigated at four locations: upstream (S1 and S2) and downstream (S3 and S4). Forty-eight genera of phytoplankton and zooplankton have been identified belonging to ten classes (Bacillariophyceae, Chlorophyceae, Zygnematophyceae, Cyanophyceae, Euglenopyceae, Protozoa, Rotifers, Copepoda, Cladocera, and Insecta) based on the findings. Winter was dominated by phytoplankton (Navicula spp., Nitzchia spp., Diatom spp.); summer and monsoon by zooplankton (Daphnia spp., Cyclops spp., Keratella spp., Brachionus spp.). Plankton communities of the tributary were assessed using diversity indices (Shannon-Weiner's index (H), Simpson's diversity index (1-D), and Evenness Index (E)). Seasonal variations in water temperature, specific conductivity, total dissolved solids, dissolved oxygen, nitrate, and ammonium ions were found to be statistically significant (p<0.05). Canonical Correspondence Analysis, K-dominance plots, cluster analysis, and NMDS analysis showed the dynamic nature of the plankton communities with seasonal physiochemical variations in the unexplored Himalayan tributary. The plankton communities exhibited significant temporal fluctuations with physicochemical factors.
Assuntos
Copépodes , Diatomáceas , Animais , Plâncton , Monitoramento Ambiental , Fitoplâncton , Zooplâncton , ÍndiaRESUMO
Schizothorax curvifrons is a morphometrically and meristically most variable and economically valuable promising fish food from Kashmir Valley. Since there is a lack of information on stock structure of wild populations on this species, this study was aimed to investigate the intraspecific variation of this important snowtrout. For this, two rivers and one lake in Kashmir Himalaya were sampled from January 2011 to October 2012. Fish body measurements were taken and morphometric characters using the truss network system was constructed. Altogether, 506 fish specimens were collected. Data were subjected to principal component analysis, discriminant function analysis and univariate analysis of variance. The first principal component explained 63.44% of total variation, while second and third components explained 8.34% and 5.31%, respectively. The step-wise discriminant function analysis retained two variables that significantly discriminated the populations. Using these variables 83.4% of the original specimens were classified into their correct groups and 81.1% of the cross-validated (leave one out procedure) specimens were classified into their correct groups. All of the total 31 transformed truss measurements exhibited highly significant (p<0.001) differences between the populations. This represents the first attempt on stock structure of S. curvifrons; therefore, this study will hopefully guide fisheries taxonomists about its current stock structure and would help in its management and conservation programme across Kashmir Himalaya area.
Schizothorax curvifrons es un alimento para peces, morfométricamente y merísticamente más variable y de mayor valor económico del Valle de Kashmir. Dado que existe una falta de información sobre la estructura de las poblaciones silvestres de esta especie, este estudio tuvo como objetivo investigar la variación intraespecífica de esta importante trucha de nieve. Para ello, se tomaron muestras de dos ríos y un lago en Kashmir Himalaya, de enero 2011 a octubre 2012. Con las mediciones de los peces se construyó una red truss. En total, se recolectaron 506 muestras de peces. Los datos se sometieron a análisis de componentes principales, análisis de función discriminante y el análisis univariante de la varianza. El primer componente principal explicó 63.44% de la variación total, mientras que los componentes segundo y tercero explicaron el 8.34% y 5.31%, respectivamente. El análisis discriminante por etapas, retuvo dos variables que discriminaron significativamente las poblaciones. El uso de estas variables de 83.4% de los especímenes originales se clasificaron en sus grupos correctos y 81.1% de la validación cruzada (deja fuera un procedimiento) especímenes fueron clasificados en sus grupos correctos. Todas las mediciones para entramados transformados, del total de 31, mostraron diferencias altamente significativas (p<0.001) entre las poblaciones. Esto representa el primer intento de obtener la estructura de la población de S. curvifrons, por lo tanto, este estudio espera orientar a los taxonomistas de peces acerca de la estructura de la población actual y ayudar en su manejo y poder establecer un programa de conservación en el área de Kashmir Himalaya.