Human fetal brains were obtained after medical termination of pregnancy at 8-10 wk from informed patients. A definite regionalization of AChE was found in the brain of the fetus, with cerebellum recording the highest and cerebral hemisphere the lowest activity. Optimum conditions for the cerebellar AChE activity were determined with respect to molarity of the buffer, pH, temperature, and concentrations of substrate (acetylthiocholine iodide), activators (NaCl, MgCl2), and thiol indicator (dithiobisnitrobenzoic acid). In vitro inhibition of cerebellar AChE with two commercial pesticides, Metacid-50 (O,O-dimethyl p-nitrophenyl phosphorothioate) and carbaryl (N-methyl naphthyl-1-carbamate), were compared with pure anticholinesterase agents, diisopropylfluorophosphate (DFP) and physostigmine (eserine). In general, organophosphates are more neurotoxic than carbamate compounds, as evidenced by higher degree of AChE inhibition by DFP and Metacid-50 as compared to eserine and carbaryl. Assays were also done with psychotropic drugs by employing the procedure of in vitro AChE inhibition kinetics, and it was found that psychotropic drugs are less potent than organophosphate and carbamate compounds. Results indicate that pure and commercial organophosphates and carbamates and psychotropic drugs are all able to significantly alter the AChE activity. Thus exposure of the mother to these environmental toxicants may adversely affect the fetal neural functions.

In the context of Climate change, greenhouse gas mitigation is one of the major concerns of the present era. Carbon sequestration by green plants is one of the most important processes for the reduction of carbon dioxide emission. Trees are the major sinks for atmospheric carbon. In the present study we evaluated the stored carbon in the dominant trees of Dhruba Chand Halder College (formerly Dakshin Barasat College) campus through the assessment of Above Ground Stem Biomass (AGSB) and Above Ground Stem Carbon (AGSC) of each species. AGSB ranged from 0.631 tonnes (Delonix regia) to 21.343 tonnes (Swietenia macrophylla) and AGSC ranged from 0.291 tonnes (Delonix regia) to 10.437 tonnes (Swietenia macrophylla) during study period. The assessment of the carbon dioxide equivalent for the species reveals considerable potential of the trees in off-setting atmospheric carbon dioxide.

The current global fisheries production is *160 million tonnes. The quantum is gradually rising as a result of increases in aquaculture production. A number of climate-related threats to capture both the fisheries and aquaculture are identified, but we have high uncertainty in predictions of the future fisheries production because of uncertainty over the future global aquatic net primary production and the transfer of this production through the food chain to human consumption. Recent changes in the distribution and productivity of a number of fish species can be ascribed with high confidence to regional climate variability, such as the El Niño-Southern Oscillation. The future production may increase in some high-latitude regions because of warming and decreased ice cover, but the dynamics in low-latitude regions are governed by different processes, and production may decline as a result of reduced vertical mixing of the water column and, hence, reduced recycling of nutrients. There are strong interactions between the effects of fishing and the effects of climate because fishing reduces the age, size and geographic diversity of populations and the biodiversity of marine ecosystems, making both more sensitive to additional stresses such as climate change-induced salinity oscillation. The estuaries in the lower Gangetic delta at the apex of Bay of Bengal are noted for contrasting spatial variation of salinity. The Hooghly estuary in the western sector is relatively low saline compared to the Matla estuary in the central sector on account of receiving the fresh water discharge from the Farakka barrage. The central sector is hyper saline due to siltation of the Bidyadhari River since the late fifteenth century. The present study evaluates the condition factor of fourteen commercially important fin fish species (that constitute *75 % of the fishes in the catch basket) collected from the Hooghly and Matla estuaries in the western and central sectors of the lower Gangetic delta, respectively. Relatively higher values of condition factor of all the species collected from the Hooghly estuary (compared to those collected from the Matla estuary) confirm the adverse effect of hyper salinity on the growth and condition factor of the species.

We monitored the Condition Index (CI) of Labeo rohita, which is an important indicator to evaluate the health and well-being of the cultured fish. In this pilot project, we initiated the culture with Labeo rohita as a candidate species in 12 rain water stocked ponds at Diamond Harbour during March, 2022 to October, 2022 and computed monthly condition index considering the mean weight and length of the cultured species (n = 65 for each pond). Simultaneously we measured the relevant hydrological parameters like surface water temperature, Dissolved Oxygen (DO), surface water pH, dissolved NO3, PO4 and SiO3 for all the ponds. We observed significant positive correlations of CI with surface water temperature, DO, and surface water pH, and significant negative correlations with dissolved NO3 and PO4. The results reveal the use of CI of Labeo rohita as proxy to well-being of the species. Bangladesh J. Zool. 50(3): 309-319, 2022

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