Insights on Fish Gut Microbiome - A Review


  • Rayees Ahmad Bhat Department of Zoology, Kurukshetra University, Kurukshetra
  • Oshin Dhillon Department of Zoology, Kurukshetra University, Kurukshetra
  • Farhana Hoque ICAR-Central Institute of Freshwater Aquaculture, Bhubaneswar, Odisha
  • Jitendra Kumar Sundaray ICAR-Central Institute of Freshwater Aquaculture, Bhubaneswar, Odisha



Fish physiology, Gut microbes, Metagenomics, Microbiome


Fish continues to attract considerable scientific interest as they are the most diverse community of vertebrates and a major component of a growing global aquaculture market. Complex assemblages of microbes, collectively known as the gut microbiota, colonize the digestive tracts of vertebrates. The gut microbiome plays a key role in fish health by stimulating immune system growth, assisting in the acquisition of nutrients, and outcompete opportunistic pathogens. Key innovations in recent years include the incredible rise in research of microbiomes, driven by advances in high-throughput sequencing technologies. The manipulation of fish gut microbiota to increase health and diet is gaining popularity. To date, most research in this area has concentrated on humans, and our knowledge of the microbiota in fish guts is minimal. This review gives an insight into the research of fish gut microbiota, including their development, variation with habitat, factors affecting gut microbial composition, their role in fish physiology, methods of characterization, application and research gaps, which can guide the development of probiotics, prebiotics and other novel additives to improve the production of healthy fish, and promote sustainable aquaculture.


Download data is not yet available.


Metrics Loading ...




How to Cite

Bhat, R. A., Dhillon, O., Hoque, F., & Sundaray, J. K. (2023). Insights on Fish Gut Microbiome - A Review. JOURNAL OF AQUACULTURE, 32(2), 01–33.



Review Article


Abd El-Rhman, A.M., Khattab, Y.A. and Shalaby, A.M., 2009. Micrococcus luteus and Pseudomonas species as probiotics for promoting the growth performance and health of Nile tilapia, Oreochromis niloticus. Fish & Shellfish Immunology, 27(2):175-180.

Adhikari, S., 2003. Effect of calcium and magnesium hardness on acute copper toxicity to Indian major carp, Labeo rohita (Hamilton) and catfish, Channa punctatus (Bloch). Aquaculture Research, 34(12):975-980.

Alsaphar, S.A. and Al-Faragi, J.K., 2012. Isolation of lactic acid bacteria (LAB) species as probiotic from intestinal contents of common carp Cyprinus carpio L. Journal of Biotechnology Research Center, 6(1):88-95.

Asaduzzaman, M.D., Iehata, S., Akter, S., Kader, M.A., Ghosh, S.K., Khan, M.N.A. and AbolMunafi, A.B., 2018. Effects of host gut-derived probiotic bacteria on gut morphology, microbiota composition and volatile short chain fatty acids production of Malaysian Mahseer Tor tambroides. Aquaculture Reports, 9:53-61.

Askarian, F., Kousha, A., Salma, W. and Ringø, E., 2011. The effect of lactic acid bacteria administration on growth, digestive enzyme activity and gut microbiota in Persian sturgeon (Acipenser persicus) and beluga (Huso huso) fry. Aquaculture nutrition, 17(5):488-497.

Askarian, F., Sperstad, S., Merrifield, D.L., Arun Kumar, R. and Ringø, E., 2012. The effect of different feeding regimes on enzyme activities of gut microbiota in Atlantic cod (Gadus morhua L.). Aquaculture Research,44(5):841-846.

Askarian, F., Zhou, Z., Olsen, R.E., Sperstad, S. and Ringø, E., 2012. Culturable autochthonous gut bacteria in Atlantic salmon (Salmo salar L.) fed diets with or without chitin. Characterization by 16S rRNA gene sequencing, ability to produce enzymes and in vitro growth inhibition of four fish pathogens. Aquaculture, 326:1-8.

Austin, B., 1982. Taxonomy of bacteria isolated from a coastal, marine fish-rearing unit. Journal of Applied Microbiology, 53(2):253-268.

Austin, B., 2006. The bacterial microflora of fish, revised. The scientific world journal, 6:931- 945.

Bairagi, A., Sarkar Ghosh, K., Sen, S.K. and Ray, A.K., 2004. Evaluation of the nutritive value of Leucaena leucocephala leaf meal, inoculated with fish intestinal bacteria Bacillus subtilis and Bacillus circulans in formulated diets for rohu, Labeo rohita (Hamilton) fingerlings. Aquaculture Research, 35(5):436-446.

Bakke, I., Coward, E., Andersen, T. and Vadstein, O., 2015. Selection in the host structures the microbiota associated with developing cod larvae (Gadus morhua). Environmental microbiology, 17(10):3914-3924.

Bakke-McKellep, A.M., Penn, M.H., Salas, P.M., Refstie, S., Sperstad, S., Landsverk, T., Ringø, E. and Krogdahl, AEffects of dietary soyabean meal, inulin and oxytetracycline on intestinal microbiota and epithelial cell stress, apoptosis and proliferation in the teleost Atlantic salmon (Salmo salar L.). British Journal of Nutrition, 97(4):699-713

Balcazar, J.L., Vendrell, D., Blas, I.D., Ruiz-Zarzuela, I. and Muzquiz, J.L., 2004. Probiotics: a tool for the future of fish and shellfish health management. Journal of Aquaculture in the Tropics, 19(4):239-242.

Balcázar, J.L., Vendrell, D., De Blas, I., Ruiz-Zarzuela, I., Gironés, O. and Muzquiz, J.L., 2006. Immune modulation by probiotic strains: quantification of phagocytosis of Aeromonas salmonicida by leukocytes isolated from gut of rainbow trout (Oncorhynchus mykiss) using a radiolabelling assay. Comparative immunology, microbiology and infectious diseases, 29(5-6):335-343.

Bandyopadhyay, P. and Das Mohapatra, P.K., 2009. Effect of a probiotic bacterium Bacillus circulans PB7 in the formulated diets: on growth, nutritional quality and immunity of Catla catla (Ham.). Fish physiology and biochemistry, 35:467-478.

Bano, N., DeRae Smith, A., Bennett, W., Vasquez, L. and Hollibaugh, J.T., 2007. Dominance of Mycoplasma in the guts of the Long-Jawed Mudsucker, Gillichthys mirabilis, from five California salt marshes. Environmental Microbiology, 9(10):2636-2641.

Barry, T., Powell, R. and Gannon, F., 1990. A general method to generate DNA probes for microorganisms. Biotechnology, 8(3):233-236.

Barton, B.A., Morgan, J.D. and Vijayan, M.M., 2002. Physiological and condition-related indicators of environmental stress in fish. Biological Indicators of Aquatic Ecosystem Stress, 2(2):111-148.

Bergh, Ø., Naas, K.E. and Harboe, T., 1994. Shift in the intestinal microflora of Atlantic halibut (Hippoglossus hippoglossus) larvae during first feeding. Canadian Journal of Fisheries and Aquatic Sciences, 51(8):1899-1903.

Bernfeld, P., 1955. Amylases a and b. In: Colowick SP, Kaplan NO (eds) Methods in enzymology. Academic, New York.

Beveridge, M.C.M., Sikdar, P.K., Frerichs, G.N. and Millar, S., 1991. The ingestion of bacteria in suspension by the common carp Cyprinus carpio L. Journal of Fish Biology, 39(6):825-831.

Bhatnagar, A. and Dhillon, O., 2019. Characterization, screening, and application of bacteria with probiotic properties isolated from the gut of (Hamilton). Fisheries & Aquatic Life, 27(4):178-189.

Bhatnagar, A., Raparia, S. and Kumari, S., 2012. Influence of isolated Bacillus coagulans on growth performance and digestive enzyme activities of Catla catla. Journal of Nature Science and Sustainable Technology, 6(3):237-253.

Bledsoe, J.W., Peterson, B.C., Swanson, K.S. and Small, B.C., 2016. Ontogenetic characterization of the intestinal microbiota of channel catfish through 16S rRNA gene sequencing reveals insights on temporal shifts and the influence of environmental microbes. PloS one, 11(11):p.e0166379.

Burbank, D.R., LaPatra, S.E., Fornshell, G. and Cain, K.D., 2012. Isolation of bacterial probiotic candidates from the gastrointestinal tract of rainbow trout, O ncorhynchus mykiss (W albaum), and screening for inhibitory activity against F lavobacterium psychrophilum. Journal of Fish Diseases, 35(11):809-816.

Burr, G., Gatlin III, D. and Ricke, S., 2005. Microbial ecology of the gastrointestinal tract of fish and the potential application of prebiotics and probiotics in finfish aquaculture. Journal of the World Aquaculture society, 36(4):425-436.

Butt, R.L. and Volkoff, H., 2019. Gut microbiota and energy homeostasis in fish. Frontiers in endocrinology, 10:p.429202.

Byun, J.W., Park, S.C., Benno, Y. and Oh, T.K., 1997. Probiotic effect of Lactobacillus sp. DS-12 in flounder (Paralichthys olivaceus). The Journal of General and Applied Microbiology, 43(5):305-308.

Cahill, M.M., 1990. Bacterial flora of fishes: a review. Microbial ecology, 19:21-41.

Cai, Y., Suyanandana, P., Saman, P. and Benno, Y., 1999. Classification and characterization of lactic acid bacteria isolated from the intestines of common carp and freshwater prawns. The Journal of general and applied microbiology, 45(4):177-184.

Cantas, L., Sørby, J.R.T., Aleström, P. and Sørum, H., 2012. Culturable gut microbiota diversity in zebrafish. Zebrafish, 9(1):26-37.

Carnevali, O., Avella, M.A. and Gioacchini, G., 2013. Effects of probiotic administration on zebrafish development and reproduction. General and comparative endocrinology, 188:297-302.

Catron, T.R., Gaballah, S. and Tal, T., 2019. Using zebrafish to investigate interactions between xenobiotics and microbiota. Current Pharmacology Reports, 5:468-480. Cerezuela, R., Fumanal, M., Tapia-Paniagua, S.T., Meseguer, J., Moriñigo, M.A Histological alterations and microbial ecology of the intestine in gi

lthead seabream (Sparus aurata L.) fed dietary probiotics and microalgae. Cell and tissue research, 350:477-489.

Chen, L., Hu, C., Lai, N.L.S., Zhang, W., Hua, J., Lam, P.K., Lam, J.C. and Zhou, B., 2018. Acute exposure to PBDEs at an environmentally realistic concentration causes abrupt changes in the gut microbiota and host health of zebrafish. Environmental Pollution, 240:17-26.

Chi, C., Jiang, B., Yu, X.B., Liu, T.Q., Xia, L. and Wang, G.X., 2014. Effects of three strains of intestinal autochthonous bacteria and their extracellular products on the immune response and disease resistance of common carp, Cyprinus carpio. Fish & shellfish immunology, 36(1):9-18.

Clements, K.D., Angert, E.R., Montgomery, W.L. and Choat, J.H., 2014. Intestinal microbiota in fishes: what's known and what's not. Molecular Ecology, 23(8):1891-1898.

Clements, K.D., 1997. Fermentation and gastrointestinal microorganisms in fishes. Gastrointestinal Microbiology: Volume 1 Gastrointestinal Ecosystems and Fermentations, 156-198.

Colowick, S.P. and Kaplan, N.O., 1955. Methods in Enzymology. - 2: Preparation and Assay of Enzymes. New York, NY: Academic Press.

Cormack, W.M. and Fraile, E.R., 1990. Bacterial flora of newly caught Antarctic fish Notothenia neglecta. Polar Biology, 10:413-417.

Cummings, G.D., 1948. Bergey's Manual Of Determinative Bacteriology. American Journal of Clinical Pathology, 18(10).

Dahlgren, B.T., 1980. The effects of three different dietary protein levels on the fecundity in the guppy, Poecilia reticulata (Peters). Journal of Fish Biology, 16(1):83-97.

Das, K.M. and Tripathi, S.D., 1991. Studies on the digestive enzymes of grass carp, Ctenopharyngodon idella (Val.). Aquaculture, 92:21-32.

Das, P., Mandal, S., Khan, A., Manna, S.K. and Ghosh, K., 2014. Distribution of extracellular enzyme-producing bacteria in the digestive tracts of 4 brackish water fish species. Turkish Journal of Zoology, 38(1):79-88.

De Schrijver, R. and Ollevier, F., 2000. Protein digestion in juvenile turbot (Scophthalmus maximus) and effects of dietary administration of Vibrio proteolyticus. Aquaculture, 186(1-2):107-116.

Dehler, C.E., Secombes, C.J. and Martin, S.A., 2017. Seawater transfer alters the intestinal microbiota profiles of Atlantic salmon (Salmo salar L.). Scientific reports, 7(1):13877.

Del'Duca, A., Cesar, D.E., Diniz, C.G. and Abreu, P.C., 2013. Evaluation of the presence and efficiency of potential probiotic bacteria in the gut of tilapia (Oreochromis niloticus) using the fluorescent in situ hybridization technique. Aquaculture, 388:115-121.

Desai, A.R., Links, M.G., Collins, S.A., Mansfield, G.S., Drew, M.D., Van Kessel, A.G. and Hill, J.E., 2012. Effects of plant-based diets on the distal gut microbiome of rainbow trout (Oncorhynchus mykiss). Aquaculture, 350:134-142.

Dhanasiri, A.K., Brunvold, L., Brinchmann, M.F., Korsnes, K., Bergh, Ø. and Kiron, V., 2011. Changes in the intestinal microbiota of wild Atlantic cod Gadus morhua L. upon captive rearing. Microbial ecology, 61:20-30.

Dhillon, O., Evaluation of dietary protein requirements and role of intestinal probiotic bacteria for growth promotion in labeo calbasu Hamilton 1822.

Estruch, G., Collado, M.C., Peñaranda, D.S., Tomás Vidal, A., Jover Cerdá, M., Pérez Martıń ez, G. and Martinez-Llorens, S., 2015. Impact of fishmeal replacement in diets for gilthead sea bream (Sparus aurata) on the gastrointestinal microbiota determined by pyrosequencing the 16S rRNA gene. Plo one, 10(8):p.e0136389.

Fernandes, S., Kerkar, S., Leitao, J. and Mishra, A., 2019. Probiotic role of salt pan bacteria in enhancing the growth of whiteleg shrimp, Litopenaeus vannamei. Probiotics and antimicrobial proteins, 11:1309-1323.

Fidopiastis, P.M., Bezdek, D.J., Horn, M.H. and Kandel, J.S., 2006. Characterizing the resident, fermentative microbial consortium in the hindgut of the temperate-zone herbivorous fish, Hermosilla azurea (Teleostei: Kyphosidae). Marine Biology, 148:631-642.

Fjellheim, A.J., Playfoot, K.J., Skjermo, J. and Vadstein, O., 2012. Inter-individual variation in the dominant intestinal microbiota of reared Atlantic cod (Gadus morhua L.) larvae. Aquaculture Research, 43(10):1499-1508.

Floris, R., Manca, S. and Fois, N., 2013. Microbial ecology of intestinal tract of gilthead sea bream (Sparus aurata Linnaeus, 1758) from two coastal lagoons of Sardinia (Italy). Transitional Waters Bulletin, 7(2):4-12.

Galley, J.D., Nelson, M.C., Yu, Z., Dowd, S.E., Walter, J., Kumar, P.S., Lyte, M. and Bailey, M.T., 2014. Exposure to a social stressor disrupts the community structure of the colonic mucosa-associated microbiota. BMC microbiology, 14:1-13.

Gatesoupe, F.J., Infante, J.L.Z., Cahu, C. and Quazuguel, P., 1997. Early weaning of seabass larvae, Dicentrarchus labrax: the effect on microbiota, with particular attention to iron supply and exoenzymes. Aquaculture, 158(1-2):117-127.

Gatesoupe, F.J., 2007. Live yeasts in the gut: natural occurrence, dietary introduction, and their effects on fish health and development. Aquaculture, 267(1-4):20-30.

Gatesoupe, F.J., 1999. The use of probiotics in aquaculture. Aquaculture, 180(1-2):147-165.

Geraylou, Z., Souffreau, C., Rurangwa, E., De Meester, L., Courtin, C.M., Delcour, J.A., Buyse, J. and Ollevier, F., 2013. Effects of dietary arabinoxylan-oligosaccharides (AXOS) and endogenous probiotics on the growth performance, non-specific immunity and gut microbiota of juvenile Siberian sturgeon (Acipenserábaerii). Fish & Shellfish Immunology, 35(3):766-775.

Ghanbari, M., Kneifel, W. and Domig, K.J., 2015. A new view of the fish gut microbiome: advances from next-generation sequencing. Aquaculture, 448:464-475.

Ghosh, K., Sen, S.K. and Ray, A.K., 2002. Characterization of Bacilli isolated from the gut of rohu, Labeo rohita, fingerlings and its significance in digestion. Journal of Applied Aquaculture, 12(3):33-42.

Giatsis, C., Sipkema, D., Smidt, H., Heilig, H., Benvenuti, G., Verreth, J. and Verdegem, M., 2015. The impact of rearing environment on the development of gut microbiota in tilapia larvae. Scientific reports, 5(1):p.18206.

Givens, C.E., Ransom, B., Bano, N. and Hollibaugh, J.T., 2015. Comparison of the gut microbiomes of 12 bony fish and 3 shark species. Marine Ecology Progress Series, 518:209-223.

Fuller, R., Goldin, B.R. and Gorbach, S.L., 1992. Probiotics for humans. Probiotics: The scientific basis:355-376.

Gómez, G.D. and Balcázar, J.L., 2008. A review on the interactions between gut microbiota and innate immunity of fish. FEMS Immunology & Medical Microbiology, 52(2):145-154.

Gomez-Gil, B., Roque, A. and Turnbull, J.F., 2000. The use and selection of probiotic bacteria for use in the culture of larval aquatic organisms. Aquaculture, 191(1-3):259-270.

Gram, C., 1884. The differential staining of Schizomycetes in tissue sections and in dried preparations. Fortschitte der Medicin, 2(6):185-189.

Green, T.J., Smullen, R. and Barnes, A.C., 2013. Dietary soybean protein concentrateinduced intestinal disorder in marine farmed Atlantic salmon, Salmo salar is associated with alterations in gut microbiota. Veterinary microbiology, 166(1- 2):286-292.

Aguirre-Guzmán, G., Lara-Flores, M., Sánchez-Martıń ez, J.G., Campa-Córdova, A.I. and Luna-González, A., 2012. The use of probiotics in aquatic organisms: A review. African Journal of microbiology research, 6(21):4845-4857.

Hagi, T. and Hoshino, T., 2009. Screening and characterization of potential probiotic lactic acid bacteria from cultured common carp intestine. Bioscience, biotechnology, and biochemistry, 73(7):1479-1483.

Hansen, G.H. and Olafsen, J.A., 1989. Bacterial colonization of cod (Gadus morhua L.) and halibut (Hippoglossus hippoglossus) eggs in marine aquaculture. Applied and environmental microbiology, 55(6):1435-1446.

Hansen, G.H., Strøm, E. and Olafsen, J.A., 1992. Effect of different holding regimens on the intestinal microflora of herring (Clupea harengus) larvae. Applied and Environmental Microbiology, 58(2):461-470.

He, X., Chaganti, S.R. and Heath, D.D., 2018. Population-specific responses to interspecific competition in the gut microbiota of two Atlantic Salmon (Salmo salar) populations. Microbial ecology, 75:140-151.

Herlemann, D.P., Labrenz, M., Jürgens, K., Bertilsson, S., Waniek, J.J. and Andersson, A.F., 2011. Transitions in bacterial communities along the 2000 km salinity gradient of the Baltic Sea. The ISME journal, 5(10):1571-1579.

Holben, W.E., Williams, P., Saarinen, M., Särkilahti, L.K. and Apajalahti, J.H., 2002. Phylogenetic analysis of intestinal microflora indicates a novel Mycoplasma phylotype in farmed and wild salmon. Microbial ecology, 44:175-185.

Holzapfel, W.H. and Schillinger, U., 2002. Introduction to pre-and probiotics. Food research international, 35(2-3):109-116.

Hoshino, T., Ishizaki, K., Sakamoto, T., Kumeta, H., Yumoto, I., Matsuyama, H. and Ohgiya, S., 1997. Isolation of a Pseudomonas species from fish intestine that produces a protease active at low temperature. Letters in applied microbiology, 25(1):70-72.

Hovda, M.B., Fontanillas, R., McGurk, C., Obach, A. and Rosnes, J.T., 2012. Seasonal variations in the intestinal microbiota of farmed Atlantic salmon (Salmo salar L.). Aquaculture Research, 43(1):154-159.

Ingerslev, H.C., von Gersdorff Jørgensen, L., Strube, M.L., Larsen, N., Dalsgaard, I., Boye, M. and Madsen, L., 2014. The development of the gut microbiota in rainbow trout (Oncorhynchus mykiss) is affected by first feeding and diet type. Aquaculture, 424:24-34.

Ingerslev, H.C., Strube, M.L., von Gersdorff Jørgensen, L., Dalsgaard, I., Boye, M. and Madsen, L., 2014. Diet type dictates the gut microbiota and the immune response against Yersinia ruckeri in rainbow trout (Oncorhynchus mykiss). Fish & shellfish immunology, 40(2):624-633.

Itoi, S., Okamura, T., Koyama, Y. and Sugita, H., 2006. Chitinolytic bacteria in the intestinal tract of Japanese coastal fishes. Canadian journal of microbiology, 52(12):1158- 1163.

Iwashita, M.K.P., Addo, S. and Terhune, J.S., 2022. Use of pre-and probiotics in finfish aquaculture. In Feed and Feeding Practices in Aquaculture (pp. 269-289). Woodhead Publishing.

Jašarević, E., Howerton, C.L., Howard, C.D. and Bale, T.L., 2015. Alterations in the vaginal microbiome by maternal stress are associated with metabolic reprogramming of the offspring gut and brain. Endocrinology, 156(9):3265-3276.

Jiang, Y., Xie, C., Yang, G., Gong, X., Chen, X., Xu, L. and Bao, B., 2011. Cellulase-producing bacteria of Aeromonas are dominant and indigenous in the gut of Ctenopharyngodon idellus (Valenciennes). Aquaculture Research, 42(4):499-505.

Kamei, Y., Sakata, T. and Kakimoto, D., 1985. Microflora in the alimentary tract of Tilapia: characterization and distribution of anaerobic bacteria. The Journal of General and Applied Microbiology, 31(2):115-124.

Kamgar, M. and Ghane, M., 2012. Evaluation of Bacillus subtilis effect as probiotic on hematological parameters of rainbow trout, Oncorhynchus mykiss (Walbaum) following experimental infection with Streptococcus iniae. Journal of fisheries and aquatic science, 7(6):422.

Kashinskaya, E.N., Belkova, N.L., Izvekova, G.I., Simonov, E.P., Andree, K.B., Glupov, V.V., Baturina, O.A., Kabilov, M.R. and Solovyev, M.M., 2015. A comparative study on microbiota from the intestine of Prussian carp (Carassius gibelio) and their aquatic environmental compartments, using different molecular methods. Journal of Applied Microbiology, 119(4):948-961.

Khan, A. and Ghosh, K., 2012. Characterization and identification of gut-associated phytaseproducing bacteria in some fresh water fish cultured in ponds. Acta Ichthyologica et Piscatoria, 42(1):37-45.

Khan, A., Mandal, S., Samanta, D., Chatterjee, S. and Ghosh, K., 2011, June. Phytaseproducing Rhodococcus sp.(MTCC 9508) from fish gut: a preliminary study. Proceedings of the Zoological Society, 64:29-34.

Kim, S.H., Han, S.K. and Shin, H.S., 2006. Effect of substrate concentration on hydrogen production and 16S rDNA-based analysis of the microbial community in a continuous fermenter. Process Biochemistry, 41(1):199-207.

Korsnes, K., Nicolaisen, O., Skår, C.K., Nerland, A.H. and Bergh, Ø., 2006. Bacteria in the gut of juvenile cod Gadus morhua fed live feed enriched with four different commercial diets. ICES Journal of Marine Science, 63(2):296-301.

Lara-Flores, M. and Olvera-Novoa, M.A., 2013. The use of lactic acid bacteria isolated from intestinal tract of Nile tilapia (Oreochromis niloticus), as growth promoters in fish fed low protein diets. Latin American Journal of Aquatic Research, 41(3):490-497.

Larsen, A.M., Mohammed, H.H. and Arias, C.R., 2014. Characterization of the gut microbiota of three commercially valuable warmwater fish species. Journal of applied microbiology, 116(6):1396-1404.

Lauzon, H.L., Gudmundsdottir, S., Steinarsson, A., Oddgeirsson, M., Petursdottir, S.K., Reynisson, E., Bjornsdottir, R. and Gudmundsdottir, B.K., 2010. Effects of bacterial treatment at early stages of Atlantic cod (Gadus morhua L.) on larval survival and development. Journal of Applied Microbiology, 108(2):624-632.

Le Doujet, T., De Santi, C., Klemetsen, T., Hjerde, E., Willassen, N.P. and Haugen, P., 2019. Closely-related Photobacterium strains comprise the majority of bacteria in the gut of migrating Atlantic cod (Gadus morhua). Microbiome, 7:1-12.

Lesel, R., Fromageot, C. and Lesel, M., 1986. Cellulose digestibility in grass carp, Ctenopharyngodon idella and in goldfish, Carassius auratus. Aquaculture, 54(1- 2):11-17.

Li, T., Long, M., Gatesoupe, F.J., Zhang, Q., Li, A. and Gong, X., 2015. Comparative analysis of the intestinal bacterial communities in different species of carp by pyrosequencing. Microbial ecology, 69:25-36.

Li, X., Yan, Q., Xie, S., Hu, W., Yu, Y. and Hu, Z., 2013. Gut microbiota contributes to the growth of fast-growing transgenic common carp (Cyprinus carpio L.). PLoS One, 8(5):e64577.

Liston, J., 1956. Quantitative variations in the bacterial flora of flatfish. Microbiology, 15(2):305-314.

Liu, Y., Yao, Y., Li, H., Qiao, F., Wu, J., Du, Z.Y. and Zhang, M., 2016. Influence of endogenous and exogenous estrogenic endocrine on intestinal microbiota in zebrafish. PloS one, 11(10):e0163895.

Llewellyn, M.S., McGinnity, P., Dionne, M., Letourneau, J., Thonier, F., Carvalho, G.R., Creer, S. and Derome, N., 2016. The biogeography of the atlantic salmon (Salmo salar) gut microbiome. The ISME journal, 10(5):1280-1284.

Lyon, W.J. and Glatz, B.A., 1993. Isolation and purification of propionicin PLG-1, a bacteriocin produced by a strain of Propionibacterium thoenii. Applied and environmental microbiology, 59(1), 83-88.

MacDonald, N.L., Stark, J.R. and Austin, B., 1986. Bacterial microflora in the gastro-intestinal tract of Dover sole (Solea solea L.), with emphasis on the possible role of bacteria in the nutrition of the host. FEMS Microbiology Letters, 35(1):107-111.

Macmillan, J.R. and Santucci, T., 1990. Seasonal trends in intestinal bacterial flora of farmraised channel catfish. Journal of Aquatic Animal Health, 2(3):217-222. doi:10.1577/1548-8667(1990)002<0217:stiibf>;2.

Makridis, P., Bergh, Ø., Skjermo, J. and Vadstein, O., 2001. Addition of bacteria bioencapsulated in Artemia metanauplii to a rearing system for halibut larvae. Aquaculture International, 9:225-235.

Mandal, S. and Ghosh, K., 2013. Isolation of tannase-producing microbiota from the gastrointestinal tracts of some freshwater fish. Journal of Applied Ichthyology, 29(1):145-153.

McIntosh, D., Ji, B., Forward, B.S., Puvanendran, V., Boyce, D. and Ritchie, R., 2008. Cultureindependent characterization of the bacterial populations associated with cod (Gadus morhua L.) and live feed at an experimental hatchery facility using denaturing gradient gel electrophoresis. Aquaculture, 275(1-4):42-50.

Meng, X.L., Li, S., Qin, C.B., Zhu, Z.X., Hu, W.P., Yang, L.P., Lu, R.H., Li, W.J. and Nie, G.X., 2018. Intestinal microbiota and lipid metabolism responses in the common carp (Cyprinus carpio L.) following copper exposure. Ecotoxicology and Environmental Safety, 160:257-264.

Merrifield, D.L., Bradley, G., Baker, R.T.M. and Davies, S.J., 2010. Probiotic applications for rainbow trout (Oncorhynchus mykiss Walbaum) II. Effects on growth performance, feed utilization, intestinal microbiota and related health criteria postantibiotic treatment. Aquaculture nutrition, 16(5):496-503.

Miyake, S., Ngugi, D.K. and Stingl, U., 2015. Diet strongly influences the gut microbiota of surgeonfishes. Molecular ecology, 24(3):656-672.

Mondal, S., Roy, T. and Ray, A.K., 2010. Characterization and identification of enzyme-producing bacteria isolated from the digestive tract of bata, Labeo bata. Journal of the World Aquaculture Society, 41(3):369-377.

Moreira, F.M., Gillis, M., Pot, B., Kersters, K. and Franco, A.A., 1993. Characterization of rhizobia isolated from different divergence groups of tropical Leguminosae by comparative polyacrylamide gel electrophoresis of their total proteins. Systematic and Applied Microbiology, 16(1):135-146.

Moriarty, D.J.W., 1996. Microbial biothechnology: a key ingredient for sustainable aquaculture. Infofish Int., 4:29-33.

Morita, Y., Hasan, Q., Sakaguchi, T., Murakami, Y., Yokoyama, K. and Tamiya, E., 1998. Properties of a cold-active protease from psychrotrophic Flavobacterium balustinum P104. Applied microbiology and biotechnology, 50:669-675.

Mouchet, M.A., Bouvier, C., Bouvier, T., Troussellier, M., Escalas, A. and Mouillot, D., 2012. Genetic difference but functional similarity among fish gut bacterial communities through molecular and biochemical fingerprints. FEMS microbiology ecology, 79(3):568-580.

Mudd, A.T., Berding, K., Wang, M., Donovan, S.M. and Dilger, R.N., 2017. Serum cortisol mediates the relationship between fecal Ruminococcus and brain Nacetylaspartate in the young pig. Gut microbes, 8(6):589-600.

Muroga, K., Higashi, M. and Keitoku, H., 1987. The isolation of intestinal microflora of farmed red seabream (Pagrus major) and black seabream (Acanthopagrus schlegeli) at larval and juvenile stages. Aquaculture, 65(1):79-88.

Nandi, A., Dan, S.K., Banerjee, G., Ghosh, P., Ghosh, K., Ringø, E. and Ray, A.K., 2017. Probiotic potential of autochthonous bacteria isolated from the gastrointestinal tract of four freshwater teleosts. Probiotics and antimicrobial proteins, 9:12-21.

Navarrete, P., Mardones, P., Opazo, R., Espejo, R. and Romero, J., 2008. Oxytetracycline treatment reduces bacterial diversity of intestinal microbiota of Atlantic salmon. Journal of Aquatic Animal Health, 20(3):177-183.

Naviner, M., Giraud, E., Le Bris, H., Armand, F., Mangion, C. and Ganiere, J., 2006. Seasonal variability of intestinal microbiota in rainbow trout (Oncorhynchus mykiss), with a particular attention to Aeromonas spp. as candidate indicator of antimicrobial resistance. Revue de médecine vétérinaire, 157(12):597-602.

Nayak, S.K. and Mukherjee, S.C., 2011. Screening of gastrointestinal bacteria of Indian major carps for a candidate probiotic species for aquaculture practices. Aquaculture Research, 42(7):1034-1041.

Nayak, S.K., 2010. Role of gastrointestinal microbiota in fish. Aquaculture research, 41(11):1553-1573.

Nelson, J.A., Wubah, D.A., Whitmer, M.E., Johnson, E.A. and Stewart, D.J., 1999. Wood-eating catfishes of the genus Panaque: gut microflora and cellulolytic enzyme activities. Journal of fish biology, 54(5):1069-1082.

Nelson, T.M., Rogers, T.L., Carlini, A.R. and Brown, M.V., 2013. Diet and phylogeny shape the gut microbiota of A ntarctic seals: a comparison of wild and captive animals. Environmental microbiology, 15(4):1132-1145.

Nieto, T.P., Toranzo, A.E. and Barja, J.L., 1984. Comparison between the bacterial flora associated with fingerling rainbow trout cultured in two different hatcheries in the north-west of Spain. Aquaculture, 42(3-4):193-206.

Parris, D.J., Brooker, R.M., Morgan, M.A., Dixson, D.L. and Stewart, F.J., 2016. Whole gut microbiome composition of damselfish and cardinalfish before and after reef settlement. PeerJ, 4:e2412.

Piazzon, M.C., Naya-Català, F., Simó-Mirabet, P., Picard-Sánchez, A., Roig, F.J., Calduch-Giner, J.A., Sitjà-Bobadilla, A. and Pérez-Sánchez, J., 2019. Sex, age, and bacteria: how the intestinal microbiota is modulated in a protandrous hermaphrodite fish. Frontiers in Microbiology, 10:487511.

Pybus, V., Loutit, M.W., Lamont, I.L. and Tagg, J.R., 1994. Growth inhibition of the salmon pathogen Vibrio ordalii by a siderophore produced by Vibrio anguillarum strain VL4355. Journal of Fish Diseases, 17(4):311-324.

Rahkonen, R., 1994. Parasites of pike perch Stizostedion lucioperca (Linnaeus 1758) fry reared in two different types of natural food ponds in southern Finland. Aquaculture, 122(4):279-293.

Ramos, C.L., Thorsen, L., Schwan, R.F. and Jespersen, L., 2013. Strain-specific probiotics properties of Lactobacillus fermentum, Lactobacillus plantarum and Lactobacillus brevis isolates from Brazilian food products. Food microbiology, 36(1):22-29.

Ran, C., Hu, J., Liu, W., Liu, Z., He, S., Dan, B.C.T., Diem, N.N., Ooi, E.L. and Zhou, Z., 2016. Thymol and carvacrol affect hybrid tilapia through the combination of direct stimulation and an intestinal microbiota-mediated effect: insights from a germ-free zebrafish model. The Journal of nutrition, 146(5):1132-1140.

Rani, S., Garg, S.K., Sabhlok, V.P. and Bhatnagar, A., 2004. Intestinal enzyme activity and enzyme producing microbial flora in relation to feeding behaviour in some brackishwater teleosts. Journal of Aquaculture, 55-68.

Ransom, B.L., 2008. Intestinal microbial community composition of six Actinopterygii fish species in the southeastern United States (Doctoral dissertation, University of Georgia).

Ray, A.K., Ghosh, K. and Ringø, E.J.A.N., 2012. Enzyme-producing bacteria isolated from fish gut: a review. Aquaculture nutrition, 18(5):465-492.

Ray, A.K., Roy, T., Mondal, S. and Ringø, E., 2010. Identification of gut-associated amylase, cellulase and protease-producing bacteria in three species of Indian major carps. Aquaculture Research, 41(10):1462-1469.

Reid, H.I., Treasurer, J.W., Adam, B. and Birkbeck, T.H., 2009. Analysis of bacterial populations in the gut of developing cod larvae and identification of Vibrio logei, Vibrio anguillarum and Vibrio splendidus as pathogens of cod larvae. Aquaculture, 288(1-2):36-43.

Rengpipat, S., Rukpratanporn, S., Piyatiratitivorakul, S. and Menasaveta, P., 2000. Immunity enhancement in black tiger shrimp (Penaeus monodon) by a probiont bacterium (Bacillus S11). Aquaculture, 191(4):271-288.

Rimmer, D.W. and Wiebe, W.J., 1987. Fermentative microbial digestion in herbivorous fishes. Journal of fish Biology, 31(2):229-236.

Ringø, E. and Birkbeck, T.H., 1999. Intestinal microflora of fish larvae and fry. Aquaculture research, 30(2):73-93

Ringø, E., Schillinger, U. and Holzapfel, W., 2005. Antimicrobial activity of lactic acid bacteria isolated from aquatic animals and the use of lactic acid bacteria in aquaculture. In Biology of growing animals, 2:418-453.

Ringø, E., Sperstad, S., Myklebust, R., Refstie, S. and Krogdahl, A2006. Characterisation of the microbiota associated with intestine of Atlantic cod (Gadus morhua L.): the effect of fish meal, standard soybean meal and a bioprocessed soybean meal. Aquaculture, 261(3):829-841.

Ringø, E., Van Doan, H., Lee, S.H., Soltani, M., Hoseinifar, S.H., Harikrishnan, R. and Song, S.K., 2020. Probiotics, lactic acid bacteria and bacilli: interesting supplementation for aquaculture. Journal of applied microbiology, 129(1): 116-136.

Ringø, E.Z.Z.V., Zhou, Z., Vecino, J.G., Wadsworth, S., Romero, J., Krogdahl, AOlsen, R.E., Dimitroglou, A., Foey, A., Davies, S. and Owen, M., 2016. Effect of dietary components on the gut microbiota of aquatic animals. A never-ending story?. Aquaculture nutrition, 22(2):219-282.

Roeselers, G., Mittge, E.K., Stephens, W.Z., Parichy, D.M., Cavanaugh, C.M., Guillemin, K. and Rawls, J.F., 2011. Evidence for a core gut microbiota in the zebrafish. The ISME journal, 5(10): 1595-1608.

Rombout, J.H., Abelli, L., Picchietti, S., Scapigliati, G. and Kiron, V., 2011. Teleost intestinal immunology. Fish & shellfish immunology, 31(5):616-626.

Romero, J. and Navarrete, P., 2006. 16S rDNA-based analysis of dominant bacterial populations associated with early life stages of coho salmon (Oncorhynchus kisutch). Microbial ecology, 51:422-430.

Roy, P., Panda, S.P., Pal, A., Jayasankar, P. and Das, B.K., 2017. Ontogenetic profile of Antiviral Mx gene and its role in innate immunity in Mrigal, Cirrhinus mrigala (Hamilton 1822). Aquaculture research, 48(6):3230-3243.

Roy, T., Mondal, S. and Ray, A.K., 2009. Phytase-producing bacteria in the digestive tracts of some freshwater fish. Aquaculture research, 40(3):344-353.

Saha, S., Roy, R.N., Sen, S.K. and Ray, A.K., 2006. Characterization of cellulase-producing bacteria from the digestive tract of tilapia, Oreochromis mossambica (Peters) and grass carp, Ctenopharyngodon idella (Valenciennes). Aquaculture Research, 37(4):380-388.

Samal, S.K., Das, B.K. and Pal, B., 2014. Isolation, biochemical characterization, antibiotic susceptibility study of Aeromonas hydrophila isolated from freshwater fish. 3(12):259-267.

Sanders, M.E., Morelli, L. and Tompkins, T.A., 2003. Sporeformers as human probiotics: Bacillus, Sporolactobacillus, and Brevibacillus. Comprehensive reviews in food science and food safety, 2(3):101-110.

Savage, D.C., 1992. Growth phase, cellular hydrophobicity, and adhesion in vitro of lactobacilli colonizing the keratinizing gastric epithelium in the mouse. Applied and Environmental Microbiology, 58(6):1992-1995.

Schmidt, V.T., Smith, K.F., Melvin, D.W. and Amaral-Zettler, L.A., 2015. Community assembly of a euryhaline fish microbiome during salinity acclimation. Molecular ecology, 24(10):2537-2550.

Schmidt, V., Gomez-Chiarri, M., Roy, C., Smith, K. and Amaral-Zettler, L., 2017. Subtle microbiome manipulation using probiotics reduces antibiotic-associated mortality in fish. Msystems, 2(6):10-1128.

Sivakumar, P. and Rajan, M.R., 2015. Isolation, enzymatic and antibacterial activity of intestinal bacteria of yellow molly (Poecilia latipinna) and its role on growth, 2(5):330-333.

Sivasubramanian, K., Ravichandran, S. and Kavitha, R., 2012. Isolation and characterization of gut micro biota from some estuarine fishes. Marine Science, 2(2):1-6. Skrodenytė-Arbačiauskienė, V., Sruoga, A., Butkauskas, D. and Skrupskelis, K., 2008. Phylogenetic analysis of intestinal bacteria of freshwater sa

lmon Salmo salar and sea trout Salmo trutta trutta and diet. Fisheries Science, 74: 1307-1314.

Smriga, S., Sandin, S.A. and Azam, F., 2010. Abundance, diversity, and activity of microbial assemblages associated with coral reef fish guts and feces. FEMS microbiology ecology, 73(1):31-42.

Spanggaard, B., Huber, I., Nielsen, J., Nielsen, T., Appel, K.F. and Gram, L., 2000. The microflora of rainbow trout intestine: a comparison of traditional and molecular identification. Aquaculture, 182(1-2):1-15.

Standen, B.T., Rodiles, A., Peggs, D.L., Davies, S.J., Santos, G.A. and Merrifield, D.L., 2015. Modulation of the intestinal microbiota and morphology of tilapia, Oreochromis niloticus, following the application of a multi-species probiotic. Applied microbiology and biotechnology, 99:8403-8417.

Stephens, W.Z., Burns, A.R., Stagaman, K., Wong, S., Rawls, J.F., Guillemin, K. and Bohannan, B.J., 2016. The composition of the zebrafish intestinal microbial community varies across development. The ISME journal, 10(3):644-654.

Strøm, E.L.L.E.N. and Olafsen, J.A., 1990. The indigenous microflora of wild-captured juvenile cod in net-pen rearing. Microbiology in poecilotherms, 181-185.

Sugita, H., Kawasaki, J. and Deguchi, Y., 1997. Production of amylase by the intestinal microflora in cultured freshwater fish. Letters in Applied Microbiology, 24(2):105- 108.

Sugita, H., Miyajima, C. and Deguchi, Y., 1991. The vitamin B12-producing ability of the intestinal microflora of freshwater fish. Aquaculture, 92:267-276.

Sugita, H., Nakamura, T., Tanaka, K. and Deguchi, Y., 1994. Identification of Aeromonas species isolated from freshwater fish with the microplate hybridization method. Applied and Environmental Microbiology, 60(8):3036-3038.

Sullam, K.E., Essinger, S.D., Lozupone, C.A., O'CONNOR, M.P., Rosen, G.L., Knight, R.O.B., Kilham, S.S. and Russell, J.A., 2012. Environmental and ecological factors that shape the gut bacterial communities of fish: a meta-analysis. Molecular ecology, 21(13):3363-3378.

Sumathi, C., Mohanapriya, D., Mandal, A.B. and Sekaran, G., 2012. Production of different proteases from fish gut microflora utilizing tannery fleshing. Engineering in Life Sciences, 12(2):223-237.

Svanevik, C.S. and Lunestad, B.T., 2011. Characterisation of the microbiota of Atlantic mackerel (Scomber scombrus). International journal of food microbiology, 151(2):164-170.

Stankus, S. and Andreikėnaitė, L., 2011. Bacterioflora of digestive tract of fishes in vitro. Veterinarija ir zootechnika, 56(78):213-233.

Talwar, C., Nagar, S., Lal, R. and Negi, R.K., 2018. Fish gut microbiome: current approaches and future perspectives. Indian journal of microbiology, 58:397-414.

Thampuran and Surendran, 1998. Occurrence and distribution of Vibrio vulnificus in tropical fish and shellfish from Cochin (India). Letters in applied microbiology, 26(2):110-112.

Tovar-Ramıŕ ez, D., Mazurais, D., Gatesoupe, J.F., Quazuguel, P., Cahu, C.L. and ZamboninoInfante, J.L., 2010. Dietary probiotic live yeast modulates antioxidant enzyme activities and gene expression of sea bass (Dicentrarchus labrax) larvae. Aquaculture, 300(1-4):142-147.

Trust, T.J. and Sparrow, R.A.H., 1974. The bacterial flora in the alimentary tract of freshwater salmonid fishes. Canadian Journal of Microbiology, 20(9): 1219-1228.

Uchii, K., Matsui, K., Yonekura, R., Tani, K., Kenzaka, T., Nasu, M. and Kawabata, Z.I., 2006. Genetic and physiological characterization of the intestinal bacterial microbiota of bluegill (Lepomis macrochirus) with three different feeding habits. Microbial ecology, 51:277-284.

Uddin, N. and Al-Harbi, A.H., 2012. Bacterial flora of polycultured common carp (Cyprinus carpio) and African catfish (Clarias gariepinus). International Aquatic Research, 4:1-9.

Vasemägi, A., Visse, M. and Kisand, V., 2017. Effect of environmental factors and an emerging parasitic disease on gut microbiome of wild salmonid fish. MSphere, 2(6):10-1128.

Vatsos, I.N., 2017. Standardizing the microbiota of fish used in research. Laboratory animals, 51(4):353-364.

Verner-Jeffreys, D.W., Shields, R.J., Bricknell, I.R. and Birkbeck, T.H., 2003. Changes in the gut-associated microflora during the development of Atlantic halibut (Hippoglossus hippoglossus L.) larvae in three British hatcheries. Aquaculture, 219(1-4):21-42.

Verschuere, L., Rombaut, G., Sorgeloos, P. and Verstraete, W., 2000. Probiotic bacteria as biological control agents in aquaculture. Microbiology and molecular biology reviews, 64(4):655-671.

Vijayabaskar, P. and Somasundaram, S.T., 2008. Isolation of bacteriocin producing lactic acid bacteria from fish gut and probiotic activity against common fresh water fish pathogen Aeromonas hydrophila. Biotechnology, 7(1):124-128.

Vine, N.G., Leukes, W.D. and Kaiser, H., 2006. Probiotics in marine larviculture. FEMS microbiology reviews, 30(3):404-427.

Walter, H.E., 1984. Proteases and their inhibitors. 2. 15. 2 Method with haemoglobin, casein and azocoll as substrate. Methods of enzymatic analysis., 270-277.

Walter, J.M., Bagi, A. and Pampanin, D.M., 2019. Insights into the potential of the Atlantic cod gut microbiome as biomarker of oil contamination in the marine environment. Microorganisms, 7(7):209.

Wang, Y.B., 2007. Effect of probiotics on growth performance and digestive enzyme activity of the shrimp Penaeus vannamei. Aquaculture, 269(1-4):259-264.

Ward, N.L., Steven, B., Penn, K., Methé, B.A. and Detrich, W.H., 2009. Characterization of the intestinal microbiota of two Antarctic notothenioid fish species. Extremophiles, 13:679-685.

Wedemeyer, G., 1968. Role of intestinal microflora in the degradation of DDT by rainbow trout:(Salmo gairdneri). Life Sciences, 7(3):219-223.

Woese, C.R. and Fox, G.E., 1977. Phylogenetic structure of the prokaryotic domain: the primary kingdoms. Proceedings of the National Academy of Sciences, 74(11):5088- 5090.

Wong, S., Waldrop, T., Summerfelt, S., Davidson, J., Barrows, F., Kenney, P.B., Welch, T., Wiens, G.D., Snekvik, K., Rawls, J.F. and Good, C., 2013. Aquacultured rainbow trout (Oncorhynchus mykiss) possess a large core intestinal microbiota that is resistant to variation in diet and rearing density. Applied and environmental microbiology, 79(16):4974-4984.

Wu, S., Gao, T., Zheng, Y., Wang, W., Cheng, Y. and Wang, G., 2010. Microbial diversity of intestinal contents and mucus in yellow catfish (Pelteobagrus fulvidraco). Aquaculture, 303(1-4):1-7.

Yan, Q., Li, J., Yu, Y., Wang, J., He, Z., Van Nostrand, J.D., Kempher, M.L., Wu, L., Wang, Y., Liao, L. and Li, X., 2016. Environmental filtering decreases with fish development for the assembly of gut microbiota. Environmental microbiology, 18(12):4739-4754.

Ye, L., Amberg, J., Chapman, D., Gaikowski, M. and Liu, W.T., 2014. Fish gut microbiota analysis differentiates physiology and behavior of invasive Asian carp and indigenous American fish. The ISME journal, 8(3):541-551.

Ying, M., Yu, Q., Zheng, B., Wang, H., Wang, J., Chen, S., Nie, S. and Xie, M., 2020. Cultured Cordyceps sinensis polysaccharides modulate intestinal mucosal immunity and gut microbiota in cyclophosphamide-treated mice. Carbohydrate polymers, 235:115957.

Yoshimizu, M. and Kimura, T., 1976. Study on the intestinal microflora of salmonids. Fish pathology, 10(2):243-259.

Yoshimizu, M., Kimura, T. and Sakai, M., 1976. Studies on the intestinal microflora of salmonids, 3: The intestinal microflora of salmon living in the open sea. Bulletin of the Japanese Society of Scientific Fisheries (Japan), 1976; 42:875-884.

YOSHIMIZU, M., TAKIZAWA, H., KAMEI, Y. and KIMURA, T., 1986. Interaction between fish pathogenic viruses and microorganisms in fish rearing water: survival and inactivation of infectious pancreatic necrosis virus, infectious hematopoietic necrosis virus and Oncorhynchus masou virus in rearing water. Fish Pathology, 21(4):223-231.

Zarkasi, K.Z., Abell, G.C., Taylor, R.S., Neuman, C., Hatje, E., Tamplin, M.L., Katouli, M. and Bowman, J.P., 2014. Pyrosequencing-based characterization of gastrointestinal bacteria of Atlantic salmon (Salmo salar L.) within a commercial mariculture system. Journal of applied microbiology, 117(1):18-27.

Zhang, M., Sun, Y., Liu, Y., Qiao, F., Chen, L., Liu, W.T., Du, Z. and Li, E., 2016. Response of gut microbiota to salinity change in two euryhaline aquatic animals with reverse salinity preference. Aquaculture, 454:72-80.

Zhou, Z., Yao, B., Romero, J., Waines, P., Ringø, E., Emery, M., Liles, M.R. and Merrifield, D.L., 2014. Methodological approaches used to assess fish gastrointestinal communities. Aquaculture nutrition: Gut health, probiotics and prebiotics, 101-127.

Zhou, X., Tian, Z., Wang, Y. and Li, W., 2010. Effect of treatment with probiotics as water additives on tilapia (Oreochromis niloticus) growth performance and immune response. Fish physiology and biochemistry, 36:501-509.