<div>Background: Probiotic is the best solution (Produce antimicrobial compounds, inhibit colonization of pathogenic microorganism, increase digestive ability and confer better health to the host) as an alternative to antibiotics against various microbial infection in freshwater and marine water. The freshwater fish Cyprinus carpio was selected for this research work (due to high growth rate, high protein content, ability to survive under different climatic conditions and its availability throughout the year) to observe the effect of probiotic Enterococcus gallinarum N3 supplemented feed on its growth. 
 
Methods: In this present research work Prepared three different concentration of probiotic Enterococcus gallinarum N3 (0.1%. 0.5% and 1.0%) along with basal diet containing other ingredients (fish meal, groundnut oil cake, wheat bran, starch and Vitamin mineral premix). Initially 14 days acclimatized freshwater fish Cyprinus carpio to laboratory condition selected randomly for four treatment groups as Control (C) and probiotic feed treated T1, T2 and T3 group. The experiment was carried out for 42 days with continuous aeration, natural photoperiod of 16 hrs light and 8 hrs dark, maintain temperature constant and fishes fed diet twice daily. The feed ingredients and experimental diets analysed for proximate composition and measured Weight gain, Specific growth rate (SGR), and Feed conversion efficiency (FCE).&nbsp; 
 
Result: The proximate composition of the feed was determined as percentage dry matter in which 36.21% protein, 6.8% moisture and 7.8% of lipid. The probiotic feed experiment was conducted for 42 days&nbsp;and entire group of fishes was survived. The effect of probiotic feed on growth performance of Cyprinus carpio was measured as initial weight, final weight, weight gain, specific growth rate and feed conversion efficiency. The growth changes were observed before and after treatment with 0.1%, 0.5% and 1.0% of probiotic E. gallinarum N3 fed to Cyprinus carpio. The final weight (g) and final length (cm) was measured in treatment T1 (3.107 g; 3.32 cm), T2 (3.258 g; 3.40 cm) and T3 (3.413 g; 3.52 cm) respectively as compared with Control group C (2.255 g; 2.98 cm). The percentage weight gain obtained in group T1 (37.78%), T2 (44.45%) and (51.55%) respectively as compared with Control group C (29.54%). Maximum specific growth rate was observed in treatments T1 (0.94 % day-1), T2 (0.99% day-1) and T3 (1.02% day-1) as compared with control group C (0.56% day-1). The results showed better growth performance and feed utilization in all the three treated groups T1, T2 and T3. The best growth performance (final weight, final length, weight gain, specific growth rate and feed conversion efficiency) and feed utilization (moisture, protein and lipid) was observed best in T3 (1 g kg-1) group of fishes as compared to control C group. There was significant difference (P &gt; 0.05) in final weight, final length, weight gain, specific growth rate and feed conversion efficiency.&nbsp;</div>

Effect of Probiotic Enterococcus gallinarum N3 Supplemented Feed on Growth Performance of Freshwater Fish Cyprinus carpio

<div>Background: Antimicrobial resistance (AMR) is a rising concern in the global aquaculture sector due to the rampant prophylactic use of antibiotics. This study is aimed to determine the AMR pattern in freshwater ornamental fishes.&nbsp; 
 
Methods: Fish pathogens were isolated and identified from infected Guppy and Molly collected from ornamental fish farms. Antibiotic susceptibility testing (ABST) using disc diffusion with 36 antibiotics was performed following the disc diffusion method. The resistance gene cassettes such as Class 1 and Class 2 integron were also detected from resolved isolates.&nbsp; 
 
Result: Fish pathogens were isolated and identified as Aeromonas hydrophila, A. dhakensis, A. veronii, A. sobria, Bacillus subtilis, Comamonas testosteroni, Edwardsiella tarda, Enterobacter cloacae, Enterococcus faecalis, Kurthia gibsonii and Klebsiella aerogenes. Shannon Weiner diversity index of resolved isolates was found to be 1.366 and 2.101 for Guppy and Molly, respectively. ABST results showed an elevated resistance pattern for A. veronii, E. faecalis (Guppy), K. aerogenes, B. subtilis, E. faecalis, C. testosteroni (Molly) with higher multiple antibiotic resistance indexes (&gt;0.33). Meanwhile, all the recovered isolates were susceptible to sulphafurazole, enrofloxacin, norfloxacin and ciprofloxacin. Detection of class 1 integron in genomic and plasmid DNA reminds the rapid spread of the AMR gene through horizontal gene transfer.</div>

Prevalence, Antimicrobial Resistance and Resistance Gene Cassettes Detection in Bacterial Pathogens Isolated from Freshwater Ornamental Fishes

<div>Background: Studies pertaining to the presence of OCP residues in the freshwater and marine &ucirc;shes caught from the Thamirabarani river basin region are not available to analyze the extent of bioaccumulation to assess their safety for human consumption. Hence, this study was undertaken as a maiden work to examine the OCP residues in the fishes collected from &ucirc;ve sites spanning from the source to mouth region of the Thamirabarani river system, along with other related niches to examine the effect of environment pollution. 
 
Methods: Pesticides from fish muscle and their organs were extracted as per AOAC 2007.01 using QuEChERS method. A Gas Chromatograph model Perkin Elmer - equipped with Ni Electron Capture Detector of activity 15 MCi was used for the analysis. A volume of 1.0&micro;l of the extracts was injected. The operating conditions were capillary column Elite-5 capillary column, 60m x 0.25mm, 1.00&micro;m temperature programme: 70&ordm;C (2 min) to 180&ordm;C (I min) 25&ordm;C/min to 300&ordm;C 5&ordm;C/min, Injection temperature: 270&ordm;C, Detector temperature: 300&ordm;C, Carrier gas: Nitrogen at 1.0 mL/min, Make up gas: Nitrogen at 29 mL/min. 
 
Result: Among fishes, rohu accumulated maximum of 0.4014 to 0.605 ug/kg of DDT in station IV and V respectively. <a href="#dhananjayan_2010">Dhananjayan and Muralidharan (2010)</a> reported OCPs in 156 fishes sample from Kaveri river. The average concentration of DDT ranged between 0 and 0.605 ug/kg. <a href="#buvanaeshwari_2012">Bhuvaneshwari and Babu rajendran (2012)</a> also reported 2.8 ug/g of DDT in fishes from Kaveri river. The low occurrence of DDT in the presence study is mainly due to their rapid degradation with living organisms.</div>

<div>Occurrence of Pesticide Residues in Freshwater and Estuarine Fishes of Thamirabarani River</div>

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

Background: Foodborne infections like Listeriosis cover several disorders and are a worldwide public health emergency. Listeria monocytogenes has been isolated from various foodstuffs, including milk and fishes. MALDI-TOF mass spectrometry technique is known for its rapid and accurate identification of bacterial organisms.&nbsp; 
 
Methods: In the current research, a total of 360 samples comprising raw milk (130), milk products (125) and freshwater fishes (105) were screened for the detection of pathogenic Listeria species by using the USDA method. The recovered Listeria isolates were characterized using conventional set of biochemical analysis along with sugar fermentation tests and further confirmed by MALDI-TOF MS. The virulent nature of pathogenic Listeria isolates was also assessed by in vitro tests like hemolysis on blood agar, CAMP and PI-PLC assay.&nbsp; 
 
Result: In current study, on screening 360 animal origin food samples, three isolates were recovered from raw milk samples and identified as Listeria monocytogenes indicating an overall prevalence of Listeria monocytogenes to the tune of 0.83%. Excellent correlation was observed with identification of Listeria species using conventional phenotypic tests and advanced molecular tool Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) technique. The results depict dependability of advanced technique for rapid and reliable identification of Listeria species.

Application of MALDI-TOF Mass Spectrometry for the Assessment of Prevalence of Listeria monocytogenes in Raw Milk, Dairy Products and Freshwater Fishes

<div style="text-align: justify;">Background: Mercury is the most noxious heavy metal. Because of its environmental persistence and ability to be accumulated in the fatty tissues of aquatic organism, it poses serious threat to the fish community.&nbsp; Methods: In the present study, freshwater air breathing fish Clarias batrachus were exposed separately to different concentrations of Mercury chloride (HgCl2) for 24 hrs, 48 hrs, 72 hrs and 96 hrs. Firstly, median lethal concentration (LC50) of HgCl2 to fish was determined by Probit analysis and was confirmed by pilot test. The behavioral and locomotary changes were monitored. Result: Test group showed random irregular and rapid swimming, restless activity. Along with these activities the test group became hyperactive, started jumping and changing their direction and position in an irregular manner. Some of the noticeable physiological symptoms during the initial stage of toxicity assessment were rapid opercular movement and frequent gulping of air. Both jerky movement and rapid respiratory response were reported to be occasional and slower in the longer duration exposure. Acute toxicity assessment provides first hand information to keep a check on pollution and to observe and track rigours of aquatic ecosystems.</div>

<div style="text-align: justify;">Acute Toxicity Assessment of Mercury Chloride to Freshwater Air Breathing Fish Clarias batrachus (Linnaeus, 1758): In vivo Study&nbsp;</div>

<div>Background: Heavy metals may adversely affect the aquatic flora and fauna. Industrial effluents contributing heavy metals on entering into aquatic environment causes biochemical alterations in the fish. Heavy metals are natural components of the aquatic environment, but heavy metal levels have increased due to anthropogenic sources like industrial effluents, agricultural runoff and wastes of mining activities. All the pollutants affect the physicochemical characteristics of the water bodies, sediment and biological components and thus the quality and quantity of fish stocks.&nbsp; 
 
Methods: The present study was to assess the protein, amino acid, aspartate transaminase and alanine transaminase levels in muscle and liver tissues of Channa striata, exposure to sublethal (15, 20 and 30 mg/L) concentrations of zinc sulphate for the period of 10, 20, 30 and 40 days. Protein levels were estimated by Lowry et al. (1951). Method free amino acids were estimated by Moore and Stein (1954). Method the enzymes ALT and AST were estimated by the strategy of Rietman and Frankel (1957) as described by Bergmeyer (1965). 
 
Result: The fish exposed to zinc sulphate showed a decrease in the protein levels and increase in the amino acid, AST and ALT levels for 10, 20, 30 and 40 days in muscle and liver tissues. The observed mean data were statistically significant at P&lt; 0.05 of Student&#39;s &lsquo;t&rsquo; test. The present study indicated alterations in biochemical parameters of Channa striata due to intoxication of zinc sulphate.</div>

<div>An Evaluation of Zinc Sulphate Toxicity on Protein, Amino Acid and Transaminase Levels in Freshwater Fish, Channa striata (bloch)</div>

Background: Studies on the bacterial diseases from the Andaman and Nicobar Islands are scanty and have only two reports recorded during 1996 and 1999. A case of emaciation and abdominal dropsy caused by different strains of Aeromonas hydrophila was recorded by earlier workers in the Andaman, Islands. In the present work, a similar disease syndrome was recorded in Barbonymus gonionotus and Cyprinus carpio var. Koi. The present study served to investigate the disease&rsquo;s cause and the pathogen associated with it. 
 
Methods: This study details the isolation, biochemical and molecular characterization of three bacterial pathogens associated with emaciated, tail rot syndrome (ETS) and big belly syndrome (BBS) in B. gonionotus and C. carpio var. Koi&nbsp; respectively. Histology and re-infectivity study was also done for the infected host tissues and with Catla catla fingerlings. 
 
Result: This study constitutes the first report of three bacterial pathogens from the Andaman Islands, India viz., Aeromonas veronii, Aeromonas sp. and Pseudomonas alcaligenes causing emaciation and abdominal dropsy, with biochemical, molecular, histopathological and experimental challenge study evidence.

First Report of Two Bacterial Diseases from the Freshwater Fishes of the Andaman Islands, India

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.