Waterbirds constitute a prominent biota and reflect the ecosystem health and functionality of the freshwater wetlands. Documentation of the bird species assemblages of wetlands is therefore carried out as a part of monitoring of wetlands from a sustainability viewpoint. Using the emerging wetland of Purbasthali, West Bengal, India, as a model study area, the diversity of the associated bird species was estimated to supplement necessary information for conservation management of birds and ecosystems. The point count method was applied to count the waterbirds from each sighting location with a 25 m radius covering 360° arc and the counting period lasted 10 min for each site, and counts were made in the winter of 2016/2017. The data on the waterbirds encountered were recorded and subjected to diversity analysis, including the residential status, global population trend and feeding guilds. Apparently, the wetland was considered as suitable habitat for 27 waterbird species, which could be grouped under 24 genera, 10 families and 5 orders. Among these, the family Anatidae with maximum relative density and abundance dominated in the wetland. Out of the 27 recorded species, 5 species were widespread winter visitors, 3 species widespread resident, as well as, widespread winter visitors and 2 species were sparse local winter visitors. A globally near threatened species, the Black-headed Ibis (Threskiornis melanocephalus) was very common in the sampling sites. The waterbird assemblage in the wetland was dominated by carnivores followed by omnivores and herbivores. The abundance of the waterbirds with considerable variations in the foraging guild reflects availability and exploitation of multiple resources of the Purbasthali wetlands. Prominence in the differences in relative abundance of the different waterbirds could be linked with the heterogeneity in the habitat quality. The present information on waterbird assemblage calls for appropriate measures for conservation of the species and appropriate management of Purbasthali wetlands.

No abstract

Beyond history reach, silkworm culture has been invariably occupying as economic tool parallel to human civilization in the world's nukes and corners. "Kalika-Puran" depict vanya fabrics-Muga and Eri as "Kasuga" that was in abundant use in the Kamrup. Some other reliable historical document that reveals uses of Muga and Eri silk in Kamrupa are Kalhan's Raj Taranginii, Kautilya's Arthasastra, and Harshacharit. The famous Chinese traveller 'Huen Tsang' wrote a note on use and trade of Muga and Eri silk in Kamrupa kingdom. At the present era, there is a gap between actual production and potential production. However, Eri production in India a steady growth from 2760 mt during 2010-2011 to 5060 mt in 2015-2016 has accounted for compounded annual growth of 12.89%. In the case of Muga silk although several constraints have been prominently affecting during the last 6years, recorded a compounded growth of 6.01%. In 2010-2011 only 124 mt was produced which reach the production line of 166 mt in 2015-2016. Several interacting factors directly-indirectly are catalyzing production. Most prominent is a collaborative effort of Central Silk Board and respective states Sericulture Department implementing several farmers beneficial scheme supporting their sericulture growth. The intervention of fashion technologies and diversification of products catalyses domestic and global market demand growth of silk products. Technology intervention at different stakes has been found working. The exploitation of Seri-biodiversity resources may be instrumental in production growth. It will open a new dimension "Do Sericulture with Agriculture".

The predatory snail Huttonella bicolor (Hutton 1834) (Gastropda: Streptaxidae) was encountered along with Allopeas gracile (Hutton 1834) (Gastropoda: Subulinidae) during a survey of small land snail species from several terrestrial habitats in Kolkata, India. An evaluation of the predation of H. bicolor as a function of prey size and predator density was carried out using A. gracile as a model prey snail. The predatory interactions were noted with an increasing ratio of 1, 2 and 4 H. bicolor against 10 A. gracile of varied size classes in a defined terrarium. At the end of a 48 h period of exposure, H. bicolor was observed to consume on an average 5.32 ± 0.50 snails depending on the size class and the predator density. The predation pattern varied significantly with the prey size class, as revealed through the logistic equation, y (prey-consumed) = 1 / (1 + exp (-(0.97–0.71*size class-prey))). In a separate experiment, it was observed that the presence of H. bicolor induced a reduction in the fecundity in A. gracile, as revealed through the logistic regression, y (egg laid) = 1 / (1 + exp(-(3.45–0.67*predator-density))). The direct effect of predation and indirect effect of oviposition reduction reflect the efficacy of H. bicolor on population regulation of A. gracile. In view of conservation biological control, the use of the snail H. bicolor as a biocontrol agent may prove beneficial in situations where A. gracile is a pest.

Due to the minimal dispersal capabilities and dependency on particular microhabitat, the land snails are susceptible to anthropogenic and natural disturbances. Considering the increasing anthropogenic threats, especially in urban areas, information on species’ requirements for particular habitat is very essential for land snail conservation and sustenance. In the present commentary, diversity and distribution of small-sized land snails in relation to their microhabitat preference in urban habitats of Kolkata, West Bengal, had been carried out through the quadrat method. The information on the richness and abundance of snails and their habitat places in Kolkata, India, was used to construct a bipartite network. A total of 13 land snail species were linked with 16 microhabitats. The network indices were used to justify the specialist or generalist nature of the snail species in the context of microhabitat preference. The snail species Succinea daucina and Allopeas gracile were observed to be associated with the maximum number of habitats while species strength was highest for S. daucina. The low value of connectance (0.288, <0.5) and niche overlap (0.34), the high value of specialization index H2′ (0.58) and d′ (0.44) indicate that the snail–microhabitat interactions were highly specialized. The network ecology of snail–microhabitats illustrated in the present instance will enable the identification of preferred microhabitats, which are required for the enhancement of the population of land snails in urban areas like Kolkata, India.