Aquatic fern Azolla pinnata comprises significant high food value with a good proportion of protein, vitamins, and minerals. This study was carried out to examine the effect of fresh A. pinnata as a substitution of commercial fish feed (CFF) for Thai silver barb Barbonymus gonionotus. Post fingerlings of B. gonionotus were reared in five treatments, labeled T₁ to T₅, by substituting 0%, 25%, 50%, 75%, and 100% protein of CFF with A. pinnata protein (dry matter basis) respectively for 56 days. The specific growth rate, net production rate, protein efficiency ratio, proximate composition, and overall conditions of fish were not significantly varied between the fish reared completely with CFF and 25% substitution with A. pinnata. However, a significantly higher profit rate (431.49 USD ha⁻¹ 56 day⁻¹) was calculated for fish reared in T₂ than other treatments. In contrast, there was a significant reduction of growth and other parameters of the fish that were observed in the case where more than 25% CFF was substituted with A. pinnata. The poorest performance was observed in fish fed completely with A. pinnata, at T₅. Based on the results, 25% of CFF of Thai silver barb could be substituted with fresh A. pinnata without significantly lowering their growth and product quality and could contribute significant to a higher profit margin.

Shrimp aquaculture has become a vital industry, meeting the growing global demand for seafood. Shrimp viral diseases have posed significant challenges to the aquaculture industry, causing major economic losses worldwide. Conventional treatment methods have proven to be ineffective in controlling these diseases. However, recent advances in RNA interference (RNAi) technology have opened new possibilities for combating shrimp viral diseases. This cutting-edge technology uses cellular machinery to silence specific viral genes, preventing viral replication and spread. Numerous studies have shown the effectiveness of RNAi-based therapies in various model organisms, paving the way for their use in shrimp health. By precisely targeting viral pathogens, RNAi has the potential to provide a sustainable and environmentally friendly solution to combat viral diseases in shrimp aquaculture. This review paper provides an overview of RNAi-based therapy and its potential as a game-changer for shrimp viral diseases. We discuss the principles of RNAi, its application in combating viral infections, and the current progress made in RNAi-based therapy for shrimp viral diseases. We also address the challenges and prospects of this innovative approach.

Higher amounts of cobalt chloride (CoCl2) released by industries are regarded as environmental pollutants. The goal of the current investigation was to assess the acute toxicity of CoCl ₂ from its effects on erythrocyte morphology and hemato-biochemical indicators in stinging catfish, Heteropneustes fossilis . The fish were subjected to CoCl ₂ at five different concentrations of 0, 50, 100, 200, and 300 mg L ^−l , which were referred to as control, CC50, CC100, CC200, and CC300, respectively. Red blood cell (RBC), hemoglobin (Hb), hematocrit (Hct), platelet counts, white blood cell (WBC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), lymphocytes, granulocytes, serum protein, and blood glucose level were among the hemato-biochemical parameters of stinging catfish that were measured following a 96 h exposure period. Additionally, erythrocytic nuclear abnormalities (ENA) and erythrocytic cellular abnormalities (ECA) were evaluated in the experimental fish. As the quantity of CoCl ₂ increased, there were notable reductions in RBC, Hb, Hct, WBC, platelet counts, MCH, MCV, MCHC, lymphocytes, granulocytes, serum protein, and blood glucose levels compared to the control. When the CoCl ₂ concentration increased, the frequencies of ECA and ENA also increased significantly (P < 0.05). This work demonstrated the significant toxicity of high CoCl ₂ concentrations caused alterations in hemato-biochemical indices and deformities in the erythrocytes of stinging catfish. Thus, it is imperative to take all necessary corrective action to guarantee that the amount of CoCl ₂ in the aquatic environment stays below permissible limits.

The study was conducted to find out the effects and optimum level of dietary Spirulina platensis (Spirulina) supplementation on growth and haematological parameters of pabda (Ompok pabda). Five experimental diets were prepared containing 33% protein. Different levels of Spirulina (0% as control or S0, S2.5%, S5%, S7.5% and S10%) were supplemented at the expense of fish meal (FM), respectively. Up to 10% of the total dietary protein (33%) in the control diet was replaced by Spirulina protein in the experimental diets. The feeding experiment was carried out in five treatments with three replications for 10 weeks. The water quality parameters viz. ammonia, dissolve oxygen, pH, and temperature were within the suitable range for pabda culture. The best growth performance was observed in the fish fed with 10% Spirulina supplemented feed followed by 7.5%, 5% and 2.5% Spirulina supplemented diet (P ˂ 0.05). Maximum survival rate (98%) and hepatosomatic index (1.37) of pabda was also found in S10% Spirulina group. But the feed conversion ratio (FCR) was decreased significantly (P < 0.05) with the increasing level of Spirulina supplementation which indicated better feed utilization. In case of carcass composition of pabda, the highest percentage of crude protein and ash were observed in fish fed with 10% followed by 7.5%, 5%, 2.5% S. platensis supplemented diet (P ˂ 0.05). Likewise, haematological condition in fish fed with 10% Spirulina supplemented diet resulted better in this study. Therefore, it could be concluded that dietary supplementation of 10% S. platensis protein with FM protein may significantly improve the growth and the haematological parameters of O. pabda.

Fisheries and Aquatic Sciences