Background: There is no previous published record regarding different fish species found in fish markets of Kharagpur town. The place is internationally renowned due to first Institute of Technology of India. Due to largest railway establishment in Kharagpur town, an influx of population is always here from different states. As such their food preference and cultural practice is different. Present survey is relevant to depicts fish preference of the town dwellers and socio-economic status of market associated people. 
Methods: The study have been conducted from November 2018 to January 2020 thoroughly from 13 fish markets of Kharagpur town, West Bengal, India. Fish specimens collected, identified and preserved. Market related data have been collected from different agents, wholesaler etc. through questionnaire interviews. 
Result: During the study period it has been observed that 28 freshwater inland fish species; 6 freshwater exotic fish species; 19 marine fish species and 4 crustacean species are available in the Kharagpur town. Some marine molluscs like Loligo sp and Sepia sp are also sold here. There are different peoples, those belong from different districts of West Bengal and involved in fish marketing activities. Therefore, a marketing chain is being established which is interdependent to each other with a socio-economic framework. Some measures have been highlighted towards improvement of infrastructure, hygienic conditions.&nbsp;

​A Study on Fish Diversity, Marketing and Economics in Fish Markets at Kharagpur, West Bengal, India

Background: The present study investigated the mortality of fish reared in cemented tanks in backyard farming in Meghalaya.&nbsp; 
 
Methods: Five dead fish and two water samples from two different tanks were brought for laboratory investigation to ascertain the cause of death. The samples (water and fish) were subjected to arrays of microbiological and biochemical tests to detect Escherichia coli, Salmonella sp., Aeromonas sp., Vibrio sp. and Listeria sp. by culture and molecular methods respectively.&nbsp; 
 
Result: The present study showed that all the fish samples were found to be negative for Vibrio sp. but three samples were positive for Aeromonas sp. by PCR against the genes ahh1 (130bp) and aerA (309bp) and one of the fish samples was also positive for Salmonella sp.&nbsp; The most Probable Count (MPN) of the water samples was not satisfactory i.e. &gt;40 MPN/ 100 ml, the content of dissolved oxygen was also low and two of the water samples were also positive for Aeromonas sp. by PCR for the same genes. Thus, from the investigation results the death of fish was inferred due to multiple factors viz. to low dissolved oxygen, very high microbial load and detection of Salmonella sp. and Aeromonas sp. Further intervention was suggested regarding optimum holding time, pH, aeration, dissolved oxygen, stocking density, clean water and feeds to control the mortality and future prevention.

Investigation of Mortality of Fishes in Backyard Fish Farming in Meghalaya by Culture and Molecular Methodsa

Background: The study focuses on understanding the factors that influence the knowledge level and adoption of scientific fish farming practices by the members of Fish Farmers Producer Organizations (FFPOs) because they play a crucial role in the fish farming sector and have the potential to drive the adoption of scientific practices. 
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Methods: The research was conducted in Purba Medinipur District, West Bengal, in 2023. From four FFPOs, total 120 respondents were chosen as sample using simple random sampling. Primary data were collected through pretested structured interview schedule. Knowledge index and adoption quotient were measured to categorize the responses of the respondents. Stepwise liner regression is done for a definite conclusion. 
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Result: The study found that most respondents were middle-aged (68.33%), with educational attainment up to the secondary level (31.66%) and had moderate farming experience (55%). Approximately 40% of the respondents reported high utilization of information sources and highest portion attended three to four training sessions (45.83%). Regarding the level of knowledge in recommended scientific fish farming, 38.33% of the respondents fell into the medium category, followed by 34.17% who possessed a high level of knowledge. Regarding the extent of adoption of fish farming practices, 36.67% respondents reported a medium level of adoption, followed by a high level (32.5%). Furthermore, the study found that utilization of information sources (t = 4.595), risk orientation (t = 3.165) and training attended (t = 2.606) were the strongest positive predictors of respondents&rsquo; knowledge levels (1% sig. level). Regarding the extent of adoption, the source of information utilization (t = 9.203), scientific orientation (t = 4.861) and education (t = 3.085) were the strongest positive predictors (1% sig. level).&nbsp;

Knowledge Level and Extent of Adoption of Scientific Fish Farming Practices among Members of Fish Farmers Producer Organizations

Background: Dissolved oxygen in water is an important limiting factor for fish. In this study, the suffocation point and transcriptomes analysis of&nbsp;Acrossocheilus fasciatus with different age and gender are helpful to analyze the effects of gender and age on extreme hypoxia tolerance. 
 
Methods: First of all, we compared the difference in tolerance to extreme hypoxia among 15 fish from male adult fish, female adult fish and juvenile fish of Acrossocheilus fasciatus in each group by asphyxiation point experiment. Then, we analyzed the molecular mechanism of extreme hypoxia tolerance difference between male and female adult fish and juvenile fish by transcriptomics.&nbsp; 
 
Result: Female adult fish of Acrossocheilus fasciatus showed the strongest tolerance to extreme hypoxia in the asphyxiation point experiment. In transcriptomes experiments in all samples, we found that the expression of ncoa4 and facl4 was significantly down regulated and the expression of jnk, gpx4 and jip-1 was significantly increased in females adult fish.

​Molecular Mechanism of Extreme Hypoxia Tolerance Difference between Male and Female Adult Fish and Juvenile Fish of Acrossocheilus fasciatus by Transcriptomics

Background: Carangidae is a family of ray-finned fish within the order Carangiformes which are invaded by different parasite species and the rate of parasitism changed regarding different factors. This study aimed to provide information about the relationship between fish size and sex on the parasites that infect fish within the family Carangidae in Saudi Arabia.&nbsp; 
 
Methods: A total of 90 Carangoides caeruleopinnatus specimens were collected from the Red Sea. The size of the fish was taken in grams (for weights) and centimeters (for lengths), respectively, as well as fish sex was determined. Fish organs were examined for parasitic infection.&nbsp; 
 
Result: There is a relationship between the length, weight and sex of fish hosts on the incidence of parasitic infection in the examined fish. Larger fish size is heavily parasitized than smaller ones which provide a greater surface for infection. In addition, the mean weight of uninfected samples was considerably higher than infected which suggested a weight loss because of parasitic infection. Parasitism in fish has been reported to be sex-biased, with males suffering greater susceptibility than female fish. This study reflects the rate of parasitism in the coastal trevally, Carangoides caeruleopinnatus, concerning fish length as well as their sex.

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Digenetic Parasite Diversity of the Coastal Trevally Fish, Carangoides caeruleopinnatus: Factors Influencing Parasitism

Background: Knowledge is a critical input for solving sustainable resource management issues. The study was conducted to determine the factors that influence the knowledge and attitudes of fishers about fish diversity and conservation in the Siang River of Arunachal Pradesh. 
 
Methods: This study used a descriptive research design. The data were collected from randomly selected 90 respondents from two blocks of East Siang District of Arunachal Pradesh with the help of a structured interview schedule and participant observation technique. The knowledge levels of the fishers were measured under three domains: conservation strategies, reservoir ecology and fishing practices.&nbsp; 
 
Result: The findings of the study revealed that the majority (53.33%) of respondents had a medium level of knowledge in three domains. Correlation analysis revealed that fishing experience and annual fishing days were positively and significantly correlated with knowledge level at a 1 per cent level of probability, whereas age and annual income were positively and significantly correlated with knowledge level at a 5 per cent level of probability. Gender, caste, education, family size, family type, average monthly catch and average fishing duration were not associated with the knowledge level of respondents about fish diversity and conservation. The attitude level of respondents was categorized into three categories: positive, neutral and negative. The findings of the study indicated that the majority of respondents (63.33%) had positive attitudes towards fish diversity and conservation, whereas 23.33 per cent had neutral attitudes and 13.34 per cent had negative attitudes toward fish diversity and conservation.&nbsp;

Factors Influencing the Knowledge and Attitudes of Fishermen about Fish Diversity and Conservation

Background: The study aimed to evaluate proximate and amino acids profile of selected freshwater species from Nagpur, India. Nutritional composition of calbasu (Labeo calbasu), silver carp (Hypophthalmichthys molitrix), tilapia (Oreochromis niloticus) and pangasius (Pangasianodon pangasius) was investigated to make aware the consumer about the present nutrient composition of these fish. 
 
Methods: Iced Calbasu, Silver carp, Tilapia and Pangasius fish were procured from Mayo fish market, Nagpur, Maharashtra, India and brought to the laboratory of Fish Processing Technology, College of Fishery Science, Nagpur. The marketable sized (average weight of 0.5-1.3 kg) fish were used for evaluation of proximate composition the methods of AOAC (2005). The amino acids profiling of fish samples were assessed by using High Performance Liquid Chromatography (HPLC, Shimadzu LC-6A). 
 
Result: The variation (p&lt;0.05) in nutrient composition viz. proximate and amino acids of these fish mainly due the effect of feed composition, feeding habits, geographical condition and availability of feed etc. The major components of proximate composition, moisture (75.75-77.53%), protein (14.52-18.01%), lipids (2.45-6.71%) and ash (1.10-2.09%) were recorded. The protein content was relatively stable in all species. The carbohydrate was found to be lower than 1.5%. The energy value of the fish species was between 94.81-123.51 Kcal. The pangasius had higher energy value due to high amount of fat content.&nbsp; During the study, the concentrations of essential amino acids (EAA) in all fish species ranged from 25.48 g/100 g to 29.41 g/100 g, while amounts of non-essential amino acids (NEAA) ranged between 27.94 g/100 g and 31.27 g/100 g. Lysine (5.14-6.31 g/100 g) and glutamic acid (6.26-8.72 g/100 g) were the most predominant amino acids found in EAA and NEAA respectively in all species. The higher level of essential amino acids was found in tilapia fish followed by silver carp, calbasu and pangasius. The results of the present study revealed that, all species have high nutritional value in terms of proximate and amino acids to offer positive health benefits upon consumption.

Proximate and Amino Acid Composition of Freshwater Fish of Nagpur, Maharashtra, India

<div>Background: Assam being a riverine state is home to n4umerous fish species that has been relished on for generations. However, fish being a perishable item, they need to be preserved for their availability throughout the year and to minimise wastage. The fish Labeo bata is a freshwater medium sized Indian minor carp which is very popular among the locals because of its characteristic taste and their high health ameliorating effects. Therefore, considering these facts, the present study focused on preparation and quality evaluation of fish powder from a minor carp, Labeo bata. 
 
Methods: Fresh fish collected from local fish market of Raha, Nagaon, Assam were dressed, washed and dehydrated to prepare fish powder. The prepared fish powder was evaluated for their nutritional composition, functional properties, sensory properties and shelf life as per standard protocols. 
 
Result: The results indicated that the moisture, protein, fat and ash content of prepared fish powder was 4.52, 63.87, 13.04 and 2.96 g/100 g respectively. The prepared flour had superior functional characteristics with bulk density, water absorption capacity, fat absorption capacity and foaming capacity of 0.53 g/ml, 145.00 ml/00 g, 99.00 ml/100 g and 32.20 per cent respectively. The product also displayed good shelf life when evaluated in terms of changed in moisture, free fatty acid (FFA), peroxide value (PV), total plate count (TPC) and pH across storage for a period of 90 days. The change in moisture, FFA, PV, TPC and pH content varied from 4.52-5.40 g/100 g; 0.08-0.22 per cent; 1.00-4.11 mEq O2/Kg; 3.12-4.23 log cfu/g and 6.22-6.80 respectively.</div>

Quality Evaluation of Fish Powder Developed from Labeo bata, a Minor Carp of Assam

<div>Background: Freshwater Asian catfish, Pangasianodon hypophthalmus (pangas) is one of the fastest growing exotic species throughout world including India. Most recently, it has been considered as a potential candidate species for carp diversification especially in northern states of India including Punjab and Haryana. In Pangas culture, fish meal is used as primary protein source pertaining to its excellent amino acid profile, palatability and high nutritive value. However, due to continuously rising cost, limited availability and quality variations of fish meal, there is need to find out less expensive alternative quality protein sources. Among these, fish silage is easy to prepare product with high nutritional value and shelf life. &nbsp;In this view, the experimental study was conducted to evaluate the possibility of replacing fish meal with fish silage supplemented diets on growth and health status of Pangas catfish. 
 
Methods: Indoor study was conducted in FRP pools (1.5&times;1&times;0.75m) for 120 days (July &ndash; October 2018) to evaluate the effect of acid fermented fish silage (prepared from fish waste collected from local fish market of Ludhiana, Punjab) for Pangas catfish fry. To study the effect of fish silage, four experimental diets were formulated by replacing fishmeal @ 50% and 100% and mixture of soybean and groundnut meal @ 25% and 50% levels from control diet along with one reference diet without any animal protein source (neither fish meal nor fish silage) 
 
Result: The overall results of present study revealed that fish silage can be incorporated (100% replacement of fish meal with fish silage) in the diet of Pangas catfish fry (P. hypophthalmus) with improved growth and feed utilization along with positive influence on health status of fish in terms of general haematology, biochemistry and anti-oxidant status.</div>

<div>Effect of Fish Silage Supplemented Diets on Growth and Health Status of Pangas Catfish, Pangasianodon hypophthalmus Fry</div>

<div>Background: Aquaculture is one of the most rapidly expanding food production sectors. Due to intensification, declining water quality parameters negatively impact fish production and the surrounding environment. Thus, it is essential to maintain optimum water quality parameters and aquatic ecosystems for sustainable fish production. This study aims to synthesize nanoparticles (NPs) and evaluate their efficiency against ammonia in cultured fish tanks under diverse conditions. 
 
Methods: Bacillus megaterium from the soil sample was isolated and identified. Iron oxide NPs were synthesized using Bacillus megaterium collected from soil samples and characterized by DLS-zeta potential, UV-vis, XRD, FTIR&nbsp;and TEM analysis. Next, synthesized NPs were evaluated under ex-situ and in-situ conditions to determine their efficacy in removing ammonia from Common carp, Cyprinus carpio culture tanks. 
 
Results: B. megaterium was isolated, identified, and 16S rRNA gene PCR-amplified sequences confirm the identification of B megaterium. DLS-zeta potential, UV-vis, XRD, FTIR&nbsp;and TEM analysis revealed the quality of synthesized NPs. B. megaterium from the soil sample was isolated and identified. The mean zeta potential of the biosynthesized NPs was between -4.65 to -6.45 mV and had an average size of 5 nm. The concentration of ammonia in aerated tanks treated with iron NPs reduced to less than 0.03 mg/dL from 0.3 mg/L. Also, fish mortality in these tanks was significantly controlled with the application of NPs. The application of NPs considerably reduced fish mortality in these fish tanks. Iron oxide NPs from B. megaterium can produce high-quality NPs that are efficient in removing ammonia from fish culture tanks. Further, exploratory studies are necessary to determine the efficacy of iron oxide NPs on aquatic organisms cultured in different environments.</div>