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Not AvailableExtreme and specialized environments are home to unique life forms and biological processes. Mud volcanoes represent less explored specialized environments of deeper earth and might harbour unique and useful microbes. With this objective, we studied the aerobic and anaerobic heterotrophic bacteria in mud volcano sediment of Andaman and Nicobar Islands, India by culture method. The bacteria identified in the volcanic sediment belonged to several genera, viz., Bacillus, Brevibacillus, Clostridium, Methylobacterium, Lutibaculum, Pseudomonas, Luteimonas, Halomonas, Acinetobacter, Kocuria, Curtobacterium, and Microbacterium in the phylum Proteobacteria (48.27 % strains), Firmicutes (27.59 %), and Actinobacteria (24.14 %) indicating wide heterotrophic diversity in the subsurface environment. Among the genera, Microbacterium and Acinetobacter were the most dominant, followed by Brevibacillus, Pseudomonas, Clostridium. The identified bacteria are known to harbour unique path ways for synthesis of different enzymes, secondary metabolites, and complex biopolymers, degrade methane and short-chain hydrocarbons, a wide variety of polysaccharides, pollutants including polyethylene, and resistance to heavy metals, heat, and desiccation that enable them to thrive in the subsurface niche and might be potentially useful in the field of agriculture, environment, and industry.Not Availabl

Occurrence, Morpho-Histopathological Characterization, and Infection Dynamics of Posthodiplostomum sp. (Strigeidida: Diplostomidae) in Cyprinid Fish of the Ganga River

A metacercarial infection of Posthodiplostomum sp. (Strigeidida: Diplostomidae) was reported in the cyprinid fish, Labeo catla and Pethia conchonius and was identified based on clinical signs, cyst morphometry and characteristic histopathological lesions. The parasite was oval-round in shape, encysted in musculocutaneous tissues, and well encapsulated. The cyst was 1.02±0.02 by 0.79±0.02 mm and 1.02±0.02 by 0.75±0.02 mm in L. catla and P. conchonius, respectively. Microscopically, the multifocal hyperpigmented areas in the musculocutaneous tissues showed pericystic melanization, focal necrosis, and an infiltration of mononuclear leukocytes. Out of the 5,820 freshwater fish examined, only 3 L. catla were found to be infected in October at the Balagarh and in August, 13 P. conchonius were found to be infected at the Farakka stretch of the Ganga River. The spatio-temporal prevalence of Posthodiplostomum sp. in L. catla and P. conchonius was <1%, indicating a lower infection rate. This is the first report of Posthodiplostomum sp. infection in P. conchonius and from the Ganga River. It is also the first report of Posthodiplostomum sp. infection in L. catla in the Ganga River

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All India Network project on Fish HealthPangasianodon hypophthalmus is a major aquaculture species in South and Southeast Asia with a high level of production. Standard physiological indices of candidate species are of great value for proper health monitoring and better production. Since fish physiology is grossly influenced by temperature, the reference intervals (RIs) of haematology and blood biochemistry of the healthy reference population of this species are established here in winter and summer seasons following standard methodologies and non-parametric statistics. Haemoglobin, alkaline phosphatase enzyme activity, glucose, urea, and creatinine levels were significantly higher in summer, while leucocyte count, globulin concentration, alanine aminotransferase enzyme activity were higher in winter suggesting the need for use of season-specific RIs for correct interpretation of test results. The normometric database would be useful in season-specific stress assessment, monitoring of well-being, and pathological progressions in this catfish which contributes about 2% to the global aquaculture production.ICA

Pharmacokinetics, bioavailability and withdrawal period of antibiotic oxytetracycline in catfish Pangasianodon hypophthalmus

Not AvailableThe antibiotic oxytetracycline (OTC) has been widely used for therapeutic and preventive management of bacterial diseases in finfish and shellfish. In the present study the bioavailability, pharmacokinetics, and withdrawal period of the OTC have been determined following in-feed administration in intensively cultured catfish Pangasianodon hypophthalmus. Furthermore, the pharmacokinetic parameters of oral route were also compared with parenteral route. Drug concentrations were measured in various tissues at different time intervals by LC-MS/MS. The study revealed the drug kinetics best followed the enterohepatic circulation model with very poor bioavailability and low blood concentration after oral administration. In the withdrawal study, after 10-days of in-feed administration at the therapeutic dose the drug reached very high concentrations in the liver and kidneys but did not attain minimum inhibitory concentrations (MICs) in blood or flesh. OTC concentration also did not exceed the recommended MRL value in flesh; however, considering high amounts of the chemical in the liver and kidneys a withdrawal period of 4 days (at 28 ? 1.5oC) is recommended for consumer safety. Poor bioavailability and non-attainment of minimum therapeutic concentration in blood and flesh do not warrant in-feed administration of OTC for control of bacterial diseases in P. hypophthalmus

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Not AvailableThe one-stripe spiny eel (Macrognathus aral, Bloch & Schneider, 1801) under the family Mastacembelidae, a native ornamental fish, were collected from the freshwater ponds and canals of West Bengal, with a purpose to raise the colony as ornamental fish broodstock. During acclimatization, fish were found to be lethargic and reluctant to consume feed followed by the appearance of deep wounds and red patches on the ventral part of the body surface. There was a mortality of 40.49% of affected fish within the next 48 hours. Post-mortem examinations revealed the presence of metacercariae inside the body cavity and on internal organs, spreading up to the buccal cavity. The abundance of the parasite was 15 to 36 numbers per fish. The length of the metacercaria varied from 5.2 mm to 9.8 mm. The metacercariae were identified as Clinostomum complanatum by light microscopy. Further, molecular confirmation of identification was done using PCR amplification and sequencing of the 18S RNA gene. This is the first report of metacercarial infestation of Clinostomum complanatum with molecular confirmation in indigenous M. aral with high ornamental value.Not Availabl

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All India Network Project on Fish HealthPangasianodon hypophthalmus is one of the most important aquaculture species in Southeast Asia, with a significant contribution to the world fish basket. Like other crops, the striped catfish suffers from bacterial diseases that demand the use of antibiotics. The present study has evaluated the safety of oxytetracycline, one of the approved and commonly used antibiotics, in this species. Juvenile stages of the fish (31.16 ± 1.03 g) were administered with the antibiotic in feed at the dose rate of 80–800 mg kg−1 body weight daily for 30 days, followed by 10 days of withdrawal observation. Fish health was assessed by the study of behaviour and feed intake, haematology, blood biochemistry, and histopathology. Results showed that up to 30 days of antibiotic treatment resulted in no significant toxic effects in terms of behaviour and fish mortality. However, fish suffered from reduced feed intake and hepatotoxicity evidenced by proliferative and degenerative changes of hepatocytes, and increase in AST and ALT enzyme activities, especially in 400–800 mg kg−1 doses which, however, recovered after withdrawal of the drug. Although few fish died from a bacterial infection at the lowest concentration of the drug used, fish were able to mount adaptive physiological responses best at 80 mg kg−1 fish dosage. The study establishes that in-feed administration of the antibiotic oxytetracycline @ 80 mg kg−1 fish biomass is safe for therapeutic use in P. hypophthalmus.ICA