Tanguar Haor (TH), an ecologically critical area (ECA) and a Ramsar site of worldwide significance, is an essential wetland ecosystem for the Bangladesh’s economic, ecological, social, and cultural aspects. Fish, aquatic plants, amphibians, reptiles, birds, and mammals are notable among the floral and faunal compositions found in this haor. Unfortunately, unsustainable exploitation of its natural resources poses a serious threat to the TH ecosystem. Therefore, the broad objective of this study was to review the status of fish biodiversity along with the driving factors of biodiversity loss and the management issues of the TH ecosystem. A total of 143 species of fishes (137 indigenous and 6 exotic) under 35 families, and 12 orders were documented during the last two decades. Species diversity of the haor has been changed over time due to the effects of climatic, anthropogenic, socioeconomic, and policy related drivers. Furthermore, high dependency on fisheries resources, poverty, and the lack of empowerment to manage the TH fishery were responsible for fish diversity decline. Therefore, ecosystem based co-management through active participation of local community, establishment of balanced fishing tactics, and strengthening alternative livelihoods for highly depended poor harvesters are strongly recommended for the proper management of this valued wetland ecosystem. Furthermore, this review proposes immediate and useful conservation initiatives for the studied wetlands, including comprehensive stock assessment, establishment of gene banks and fish sanctuaries, a combination of input and output control, and regulation with the ECA and RAMSAR guidelines.

The Lakshmi Baor Freshwater Swamp Forest (LBFSF) is a vital freshwater swamp ecosystem in northeastern Bangladesh that is renowned for its biodiversity and ecological significance. However, this unique habitat faces significant degradation owing to both natural and human influences, which threatens the biodiversity and livelihoods of local communities. This study investigated land use and land cover (LULC) changes in the Lakshmi Baor Swamp Forest from 2000 to 2020 to understand the extent and drivers of forest degradation. Using Landsat 7 and Landsat 8 data, we applied two vegetation indices, the normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI), to assess the changes in forest cover over four distinct periods: 2000–2003, 2003–2018, 2018–2020, and 2000–2020. Land cover was categorized into forest, sparse vegetation, bare land, and water using maximum-likelihood supervised classifiers, and post classification change detection was employed to track LULC dynamics over time. The analysis revealed a substantial decrease in forest area, with the NDVI-based classifications showing a decline from 59.68 to 43.77% and the EVI classifications showing a decrease from 59.54 to 41.57%. Conversely, bare land expanded significantly, with the NDVI increasing from 14.44 to 26.71% and the EVI increasing from 9.47 to 34.42%. Although the water area slightly increased, sparse vegetation exhibited minimal changes in the NDVI assessments but decreased according to the EVI. These findings highlight critical trends in forest loss and land degradation, which have direct consequences for biodiversity, ecosystem services, and local livelihoods. This study highlights the efficacy of the NDVI, which achieved an 3.64% greater overall accuracy than the EVI in assessing LULC changes. The observed degradation patterns underscore the urgent need for targeted conservation. We recommend designating the Lakshmi Baor Swamp Forest as a protected zone and implementing sustainable resource management practices to safeguard the ecosystem. These insights provide a scientific basis for policymakers and conservationists to develop strategies to mitigate further ecological losses and to support sustainable development in the region.

Reducing fishmeal (FM) use in aquafeeds is essential for sustainable aquaculture, but excessive replacement with alternative proteins may impair fish growth and physiological performance. This study evaluated the performance thresholds of graded FM replacement in probiotic‐supplemented alternative protein diets for climbing perch ( Anabas testudineus ). Four approximately iso‐nitrogenous and iso‐energetic diets were formulated using SBM and poultry by‐product meal. Diet D1 served as the control (0% FM replacement without probiotic), whereas D2, D3, and D4 contained 70%, 85%, and 100% FM replacement, respectively, and were supplemented with a multistrain probiotic containing Lactobacillus spp. and Corynebacterium glutamicum (0.2%). A total of 360 juveniles (2.52 ± 0.01 g) were fed the experimental diets for 56 days. Growth performance differed among treatments, with D1 producing the highest final body weight (9.65 g) and D4 the lowest (6.09 g). Fish fed D2 maintained final body weight (8.35 g), weight gain (231.81%), and specific growth rate (2.14% day ^{− 1} ) comparable to the control. Plasma glucose, total protein, GOT, GPT, triglycerides, and cholesterol did not differ significantly among treatments. Nitro blue tetrazolium activity did not differ significantly, whereas plasma peroxidase activity was significantly higher in D1 than in D3 and D4, with D2 showing an intermediate response. Salinity stress tolerance (LT ₅₀ ) was significantly higher in D1 (41.95 min) than in D4 (35.43 min), while D2 and D3 showed intermediate values. These findings indicate that approximately 70% FM replacement within the present probiotic‐supplemented dietary framework maintained growth performance and selected physiological responses broadly comparable to the control under the present experimental conditions, whereas complete FM replacement reduced growth performance and salinity stress tolerance. The study provides practical guidance for developing cost‐effective and environmentally sustainable feed formulations for climbing perch within a functional dietary framework rather than evaluating additive‐specific effects.