Bromelain improves the growth, biochemical, and hematological profiles of the fingerlings of Nile Tilapia, Oreochromis niloticus

Jhanani Gopalraaj; John Britto Sagaya Raj; Krishnakumar Velayudhannair; Latha Chandrakas

doi:10.7324/JABB.2022.10s207

Abstract References Article Metrics Similar Articles Request Permission Related Search Citation Alert By Google Scholar Comment On This Article

Abstract

A 6-week-long feeding trial experiment was conducted to study the efficacy of Bromelain, a blend of proteolytic enzymes present in pineapple wastes on growth performance, biochemical, and hematological profiles of the fingerlings of Nile tilapia, Oreochromis niloticus. For this, 240 Nile tilapia fingerlings (9 ± 0.11 cm) were fed a commercial diet, supplemented with different levels of pineapple peel extract (PPE) at 1:0, 1:1, 1:2, and 1:3 ratios. After 45 days of the feeding trial, growth parameters, biochemical constituents, and the level of blood cells were assessed. It was found that the growth parameters such as weight gain, feed efficiency ratio, and specific growth rate were increased (p < 0.05) along with the total protein and amino acid content and few hematological parameters; whereas the feed conversion ratio was found to be reduced significantly (p > 0.05) without changing the white blood cell count with PPE supplementation. Thus, the PPE can be a potential feed supplement in Nile tilapia aquaculture.

Keyword: Fisheries supplementation proteases resistance waste management

Citation:

Gopalraaj J, Raj JBS, Krishnakumar V, Chandrakas L. Bromelain improves the growth, biochemical, and hematological profiles of the fingerlings of Nile Tilapia, Oreochromis niloticus. J Appl Biol Biotech 2022;10(Suppl 2):73-77.

Copyright: Author(s). This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike license.

HTML Full Text

Reference

1. Hassaan MS, Mahmoud SA, Jarmolowicz S, El-Haroun ER, Mohammady EY, Davies SJ. Effects of dietary baker's yeast extract on the growth, blood indices and histology of Nile tilapia (Oreochromis niloticus L.) fingerlings. Aquacult Nutr 2018;24(6):1709-17. https://doi.org/10.1111/anu.12805
2. Hassaan MS, El-Sayed AI, Soltan MA, Iraqi MM, Goda AM, Davies SJ, et al. Partial dietary fish meal replacement with cotton seed meal and supplementation with exogenous protease alters growth, feed performance, hematological indices and associated gene expression markers (GH, IGF-I) for Nile tilapia, Oreochromis niloticus. Aquaculture 2019;503:282-92. https://doi.org/10.1016/j.aquaculture.2019.01.009
3. Hasan MR, New MB. On-farm feeding and feed management in aquaculture. FAO Fisheries and Aquaculture Technical Paper, Rome, Italy, 2013.
4. Reverter M, Bontemps N, Lecchini D, Banaigs B, Sasal P. Use of plant extracts in fish aquaculture as an alternative to chemotherapy: current status and future perspectives. Aquaculture 2014;433:50-61. https://doi.org/10.1016/j.aquaculture.2014.05.048
5. Anderson DP. Immunostimulants, adjuvants, and vaccine carriers in fish: applications to aquaculture. Annu Rev Fish Dis 1992;1(2):281-307. https://doi.org/10.1016/0959-8030(92)90067-8
6. Elferink EV, Nonhebel S, Moll HC. Feeding livestock food residue and the consequences for the environmental impact of meat. J Cleaner Prod 2008;16(12):1227-33. https://doi.org/10.1016/j.jclepro.2007.06.008
7. Golden KD, Smith-Marshall J. Characterization of bromelain from Morinda citrifolia (Noni). J Sci Res 2012;4(2):445. https://doi.org/10.3329/jsr.v4i2.8125
8. Ramli AN, Aznan TN, Illias RM. Bromelain: from production to commercialisation. J Sci Food Agric 2017;97(5):1386-95. https://doi.org/10.1002/jsfa.8122
9. Guedes JA, de Godoy Alves Filho E, Rodrigues TH, Silva MF, Souza FV, e Silva LM, et al. Metabolic profile and cytotoxicity of non-polar extracts of pineapple leaves and chemometric analysis of different pineapple cultivars. Ind Crops Prod 2018;124:466-74. https://doi.org/10.1016/j.indcrop.2018.08.026
10. Das G, Patra JK, Debnath T, Ansari A, Shin HS. Investigation of antioxidant, antibacterial, antidiabetic, and cytotoxicity potential of silver nanoparticles synthesized using the outer peel extract of Ananas comosus (L.). PloS One 2019;14(8):e0220950. https://doi.org/10.1371/journal.pone.0220950
11. Azizan A, Lee AX, Abdul Hamid NA, Maulidiani M, Mediani A, Abdul Ghafar SZ, et al. Potentially bioactive metabolites from pineapple waste extracts and their antioxidant and α-glucosidase inhibitory activities by 1H NMR. Foods 2020;9(2):173. https://doi.org/10.3390/foods9020173
12. Walsh G. Proteins: biochemistry and biotechnology. John Wiley & Sons, Hoboken, NJ, 2002.
13. Kolkovski S. Digestive enzymes in fish larvae and juveniles- implications and applications to formulated diets. Aquaculture 2001;200(1-2):181-201. https://doi.org/10.1016/S0044-8486(01)00700-1
14. Yigit NO, Bahadir Koca S, Didinen BI, Diler I. Effect of protease and phytase supplementation on growth performance and nutrient digestibility of rainbow trout (Oncorhynchus mykiss, Walbaum) fed soybean meal-based diets. J Appl Anim Res 2018;46(1):29-32. https://doi.org/10.1080/09712119.2016.1256292
15. Dawood MA, Zommara M, Eweedah NM, Helal AI. Synergistic effects of selenium nanoparticles and vitamin E on growth, immune-related gene expression, and regulation of antioxidant status of Nile tilapia (Oreochromis niloticus). Biol Trace Elem Res 2020;195(2):624-35. https://doi.org/10.1007/s12011-019-01857-6
16. Amin A, El Asely A, Abd El-Naby AS, Samir F, El-Ashram A, Sudhakaran R, et al. Growth performance, intestinal histomorphology and growth-related gene expression in response to dietary Ziziphus mauritiana in Nile tilapia (Oreochromis niloticus). Aquaculture.2019;512:734301. https://doi.org/10.1016/j.aquaculture.2019.734301
17. Van Doan H, Hoseinifar SH, Chitmanat C, Jaturasitha S, Paolucci M, Ashouri G, et al. The effects of Thai ginseng, Boesenbergia rotunda powder on mucosal and serum immunity, disease resistance, and growth performance of Nile tilapia (Oreochromis niloticus) fingerlings. Aquaculture 2019;513:734388. https://doi.org/10.1016/j.aquaculture.2019.734388
18. Magouz FI, Mahmoud SA, El-Morsy RA, Paray BA, Soliman AA, Zaineldin AI, et al. Dietary menthol essential oil enhanced the growth performance, digestive enzyme activity, immune-related genes, and resistance against acute ammonia exposure in Nile tilapia (Oreochromis niloticus). Aquaculture 2021;530:735944. https://doi.org/10.1016/j.aquaculture.2020.735944
19. Menaga M, Fitzsimmons K. Growth of the tilapia industry in India. World Aquacul 2017;48(3):49-52.
20. Ahmed I, Reshi QM, Fazio F. The influence of the endogenous and exogenous factors on hematological parameters in different fish species: a review. Aquacul Int 2020;10:1-31. https://doi.org/10.1007/s10499-019-00501-3
21. Sharma SA, Krishnakumar V, Arulraj J. Impact of Ananas comosus extract supplementation on the growth and biochemical profile of Cyprinus carpio fingerlings. Trends Fish Res 2019;8:69-
22. Lowry OH, Rosebrough NJ, Farr AL, Randall RJ. Protein measurement with the Folin phenol reagent. J Biol Chem 1951;193:265-75. https://doi.org/10.1016/S0021-9258(19)52451-6
23. Johnston MA, Davies PS. Carbohydrates of the hepatopancreas and blood tissues of Carcinus. Comp Biochem Physiol Part B 1972;41(2):433-43. https://doi.org/10.1016/0305-0491(72)90046-6
24. Folch J, Lees M, Stanley GS. A simple method for the isolation and purification of total lipides from animal tissues. J Biol Chem 1957;226(1):497-509. https://doi.org/10.1016/S0021-9258(18)64849-5
25. Lee YP, Takahashi T. An improved colorimetric determination of amino acids with the use of ninhydrin. Anal Biochem 1966;14(1):71-7. https://doi.org/10.1016/0003-2697(66)90057-1
26. Rao YV, Chakrabarti R. Enhanced anti-proteases in Labeo rohita fed with diet containing herbal ingredients. Indian J Clin Biochem 2004;19(2):132-4. https://doi.org/10.1007/BF02894272
27. Citarasu T, Sivaram V, Immanuel G, Rout N, Murugan V. Influence of selected Indian immunostimulant herbs against white spot syndrome virus (WSSV) infection in black tiger shrimp, Penaeus monodon with reference to haematological, biochemical and immunological changes. Fish Shellfish Immunol 2006;21(4):372-84. https://doi.org/10.1016/j.fsi.2006.01.002
28. Atinkut HB, Yan T, Arega Y, Raza MH. Farmers' willingness-to-pay for eco-friendly agricultural waste management in Ethiopia: a contingent valuation. J Cleaner Prod 2020;261:121211. https://doi.org/10.1016/j.jclepro.2020.121211
29. Tewari G, Ram RN, Singh A. Effect of plant base digestive enzyme 'Papain'on growth, survival and behavioural response of Cyprinus carpio. Int J Fish Aquatic Stud 2018;6:210-4.
30. Wiszniewski G, Jarmo?owicz S, Hassaan MS, Mohammady EY, Soaudy MR, ?uczy?ska J, et al. The use of bromelain as a feed additive in fish diets: growth performance, intestinal morphology, digestive enzyme and immune response of juvenile Sterlet (Acipenser ruthenus). Aquacult Nutr 2019;25(6):1289-99. https://doi.org/10.1111/anu.12949
31. Rahman M, Yang DK. Effects of Ananas comosus leaf powder on broiler performance, haematology, biochemistry, and gut microbial population. Rev Bras Zoo 2018;16;47. https://doi.org/10.1590/rbz4720170064
32. Samuel KG, Wang J, Yue HY, Wu SG, Zhang HJ, Duan ZY, et al. Effects of dietary gallic acid supplementation on performance, antioxidant status, and jejunum intestinal morphology in broiler chicks. Poult Sci 2017;96(8):2768-75. https://doi.org/10.3382/ps/pex091
33. Cai L, Li YP, Wei ZX, Li XL, Jiang XR. Effects of dietary gallic acid on growth performance, diarrhea incidence, intestinal morphology, plasma antioxidant indices, and immune response in weaned piglets. Anim Feed Sci Technol 2020;261:114391. https://doi.org/10.1016/j.anifeedsci.2020.114391
34. Bowyer PH, El-Haroun ER, Davies SJ. Dietary nucleotides enhance intestinal functional topography in European seabass (Dicentrarchus labrax). Aquacult Res 2019;20(7):1921-30. https://doi.org/10.1111/are.14078
35. Bowyer PH, El-Haroun ER, Salim HS, Davies SJ. Benefits of a commercial solid-state fermentation (SSF) product on growth performance, feed efficiency and gut morphology of juvenile Nile tilapia (Oreochromis niloticus) fed different UK lupin meal cultivars. Aquaculture 2020;523:735192. https://doi.org/10.1016/j.aquaculture.2020.735192
36. Li P, Mai K, Trushenski J, Wu G. New developments in fish amino acid nutrition: towards functional and environmentally oriented aquafeeds. Amino Acids.2009;37(1):43-53. https://doi.org/10.1007/s00726-008-0171-1
37. Lin SM, Shi CM, Mu MM, Chen YJ, Luo L. Effect of high dietary starch levels on growth, hepatic glucose metabolism, oxidative status and immune response of juvenile largemouth bass, Micropterus salmoides. Fish Shellfish Immunol 2018;78:121-6. https://doi.org/10.1016/j.fsi.2018.04.046
38. Vasconcelos TS, Thomaz MC, Castelini FR, Alvarenga PV, de Oliveira JA, Ramos GF, et al. Evaluation of pineapple byproduct at increasing levels in heavy finishing pigs feeding. Anim Feed Sci Technol 2020;269:114664. https://doi.org/10.1016/j.anifeedsci.2020.114664
39. Ribeiro L, Couto A, Olmedo M, Álvarez-Blázquez B, Linares F, Valente LM. Digestive enzyme activity at different developmental stages of blackspot seabream, Pagellus bogaraveo (Brunnich 1768). Aquacult Res 2008;39(4):339-46. https://doi.org/10.1111/j.1365-2109.2007.01684.x
40. Gómez-Limia L, Franco I, Blanco T, Martínez S. Changes in amino acids content in muscle of European Eel (Anguilla anguilla) in relation to body size. Int J Nutr Food Eng 2019;13(2):38-41.
41. Dawood MA, Koshio S, Esteban MÁ. Beneficial roles of feed additives as immunostimulants in aquaculture: a review. Rev Aquacult 2018;10(4):950-74. https://doi.org/10.1111/raq.12209
42. Jiang N, Tan NS, Ho B, Ding JL. Respiratory protein-generated reactive oxygen species as an antimicrobial strategy. Nat Immunol 2007;8(10):1114-22. https://doi.org/10.1038/ni1501
43. Sharma SA, Surveswaran S, Arulraj J, Velayudhannair K. Bromelain enhances digestibility of Spirulina-based fish feed. J Appl Phycol 2021;33(2):967-77. https://doi.org/10.1007/s10811-020-02337-4

Article Metrics

96 Views 55 Downloads 151 Total

Year

Month

Related Search

By author names

Gopalraaj J [PubMed] [Google Scholar ]

Raj J B S [PubMed] [Google Scholar ]

Velayudhannair K [PubMed] [Google Scholar ]

Chandrakas L [PubMed] [Google Scholar ]

By article title

1. Hassaan MS, Mahmoud SA, Jarmolowicz S, El-Haroun ER, Mohammady EY, Davies SJ. Effects of dietary baker's yeast extract on the growth, blood indices and histology of Nile tilapia (Oreochromis niloticus L.) fingerlings. Aquacult Nutr 2018;24(6):1709-17. https://doi.org/10.1111/anu.12805

2. Hassaan MS, El-Sayed AI, Soltan MA, Iraqi MM, Goda AM, Davies SJ, et al. Partial dietary fish meal replacement with cotton seed meal and supplementation with exogenous protease alters growth, feed performance, hematological indices and associated gene expression markers (GH, IGF-I) for Nile tilapia, Oreochromis niloticus. Aquaculture 2019;503:282-92. https://doi.org/10.1016/j.aquaculture.2019.01.009

3. Hasan MR, New MB. On-farm feeding and feed management in aquaculture. FAO Fisheries and Aquaculture Technical Paper, Rome, Italy, 2013.

4. Reverter M, Bontemps N, Lecchini D, Banaigs B, Sasal P. Use of plant extracts in fish aquaculture as an alternative to chemotherapy: current status and future perspectives. Aquaculture 2014;433:50-61. https://doi.org/10.1016/j.aquaculture.2014.05.048

5. Anderson DP. Immunostimulants, adjuvants, and vaccine carriers in fish: applications to aquaculture. Annu Rev Fish Dis 1992;1(2):281-307. https://doi.org/10.1016/0959-8030(92)90067-8

6. Elferink EV, Nonhebel S, Moll HC. Feeding livestock food residue and the consequences for the environmental impact of meat. J Cleaner Prod 2008;16(12):1227-33. https://doi.org/10.1016/j.jclepro.2007.06.008

7. Golden KD, Smith-Marshall J. Characterization of bromelain from Morinda citrifolia (Noni). J Sci Res 2012;4(2):445. https://doi.org/10.3329/jsr.v4i2.8125

8. Ramli AN, Aznan TN, Illias RM. Bromelain: from production to commercialisation. J Sci Food Agric 2017;97(5):1386-95. https://doi.org/10.1002/jsfa.8122

9. Guedes JA, de Godoy Alves Filho E, Rodrigues TH, Silva MF, Souza FV, e Silva LM, et al. Metabolic profile and cytotoxicity of non-polar extracts of pineapple leaves and chemometric analysis of different pineapple cultivars. Ind Crops Prod 2018;124:466-74. https://doi.org/10.1016/j.indcrop.2018.08.026

10. Das G, Patra JK, Debnath T, Ansari A, Shin HS. Investigation of antioxidant, antibacterial, antidiabetic, and cytotoxicity potential of silver nanoparticles synthesized using the outer peel extract of Ananas comosus (L.). PloS One 2019;14(8):e0220950. https://doi.org/10.1371/journal.pone.0220950

11. Azizan A, Lee AX, Abdul Hamid NA, Maulidiani M, Mediani A, Abdul Ghafar SZ, et al. Potentially bioactive metabolites from pineapple waste extracts and their antioxidant and α-glucosidase inhibitory activities by 1H NMR. Foods 2020;9(2):173. https://doi.org/10.3390/foods9020173

12. Walsh G. Proteins: biochemistry and biotechnology. John Wiley & Sons, Hoboken, NJ, 2002.

13. Kolkovski S. Digestive enzymes in fish larvae and juveniles- implications and applications to formulated diets. Aquaculture 2001;200(1-2):181-201. https://doi.org/10.1016/S0044-8486(01)00700-1

14. Yigit NO, Bahadir Koca S, Didinen BI, Diler I. Effect of protease and phytase supplementation on growth performance and nutrient digestibility of rainbow trout (Oncorhynchus mykiss, Walbaum) fed soybean meal-based diets. J Appl Anim Res 2018;46(1):29-32. https://doi.org/10.1080/09712119.2016.1256292

15. Dawood MA, Zommara M, Eweedah NM, Helal AI. Synergistic effects of selenium nanoparticles and vitamin E on growth, immune-related gene expression, and regulation of antioxidant status of Nile tilapia (Oreochromis niloticus). Biol Trace Elem Res 2020;195(2):624-35. https://doi.org/10.1007/s12011-019-01857-6

16. Amin A, El Asely A, Abd El-Naby AS, Samir F, El-Ashram A, Sudhakaran R, et al. Growth performance, intestinal histomorphology and growth-related gene expression in response to dietary Ziziphus mauritiana in Nile tilapia (Oreochromis niloticus). Aquaculture.2019;512:734301. https://doi.org/10.1016/j.aquaculture.2019.734301

17. Van Doan H, Hoseinifar SH, Chitmanat C, Jaturasitha S, Paolucci M, Ashouri G, et al. The effects of Thai ginseng, Boesenbergia rotunda powder on mucosal and serum immunity, disease resistance, and growth performance of Nile tilapia (Oreochromis niloticus) fingerlings. Aquaculture 2019;513:734388. https://doi.org/10.1016/j.aquaculture.2019.734388

18. Magouz FI, Mahmoud SA, El-Morsy RA, Paray BA, Soliman AA, Zaineldin AI, et al. Dietary menthol essential oil enhanced the growth performance, digestive enzyme activity, immune-related genes, and resistance against acute ammonia exposure in Nile tilapia (Oreochromis niloticus). Aquaculture 2021;530:735944. https://doi.org/10.1016/j.aquaculture.2020.735944

19. Menaga M, Fitzsimmons K. Growth of the tilapia industry in India. World Aquacul 2017;48(3):49-52.

20. Ahmed I, Reshi QM, Fazio F. The influence of the endogenous and exogenous factors on hematological parameters in different fish species: a review. Aquacul Int 2020;10:1-31. https://doi.org/10.1007/s10499-019-00501-3

21. Sharma SA, Krishnakumar V, Arulraj J. Impact of Ananas comosus extract supplementation on the growth and biochemical profile of Cyprinus carpio fingerlings. Trends Fish Res 2019;8:69-

22. Lowry OH, Rosebrough NJ, Farr AL, Randall RJ. Protein measurement with the Folin phenol reagent. J Biol Chem 1951;193:265-75. https://doi.org/10.1016/S0021-9258(19)52451-6

23. Johnston MA, Davies PS. Carbohydrates of the hepatopancreas and blood tissues of Carcinus. Comp Biochem Physiol Part B 1972;41(2):433-43. https://doi.org/10.1016/0305-0491(72)90046-6

24. Folch J, Lees M, Stanley GS. A simple method for the isolation and purification of total lipides from animal tissues. J Biol Chem 1957;226(1):497-509. https://doi.org/10.1016/S0021-9258(18)64849-5

25. Lee YP, Takahashi T. An improved colorimetric determination of amino acids with the use of ninhydrin. Anal Biochem 1966;14(1):71-7. https://doi.org/10.1016/0003-2697(66)90057-1

26. Rao YV, Chakrabarti R. Enhanced anti-proteases in Labeo rohita fed with diet containing herbal ingredients. Indian J Clin Biochem 2004;19(2):132-4. https://doi.org/10.1007/BF02894272

27. Citarasu T, Sivaram V, Immanuel G, Rout N, Murugan V. Influence of selected Indian immunostimulant herbs against white spot syndrome virus (WSSV) infection in black tiger shrimp, Penaeus monodon with reference to haematological, biochemical and immunological changes. Fish Shellfish Immunol 2006;21(4):372-84. https://doi.org/10.1016/j.fsi.2006.01.002

28. Atinkut HB, Yan T, Arega Y, Raza MH. Farmers' willingness-to-pay for eco-friendly agricultural waste management in Ethiopia: a contingent valuation. J Cleaner Prod 2020;261:121211. https://doi.org/10.1016/j.jclepro.2020.121211

29. Tewari G, Ram RN, Singh A. Effect of plant base digestive enzyme 'Papain'on growth, survival and behavioural response of Cyprinus carpio. Int J Fish Aquatic Stud 2018;6:210-4.

30. Wiszniewski G, Jarmo?owicz S, Hassaan MS, Mohammady EY, Soaudy MR, ?uczy?ska J, et al. The use of bromelain as a feed additive in fish diets: growth performance, intestinal morphology, digestive enzyme and immune response of juvenile Sterlet (Acipenser ruthenus). Aquacult Nutr 2019;25(6):1289-99. https://doi.org/10.1111/anu.12949

31. Rahman M, Yang DK. Effects of Ananas comosus leaf powder on broiler performance, haematology, biochemistry, and gut microbial population. Rev Bras Zoo 2018;16;47. https://doi.org/10.1590/rbz4720170064

32. Samuel KG, Wang J, Yue HY, Wu SG, Zhang HJ, Duan ZY, et al. Effects of dietary gallic acid supplementation on performance, antioxidant status, and jejunum intestinal morphology in broiler chicks. Poult Sci 2017;96(8):2768-75. https://doi.org/10.3382/ps/pex091

33. Cai L, Li YP, Wei ZX, Li XL, Jiang XR. Effects of dietary gallic acid on growth performance, diarrhea incidence, intestinal morphology, plasma antioxidant indices, and immune response in weaned piglets. Anim Feed Sci Technol 2020;261:114391. https://doi.org/10.1016/j.anifeedsci.2020.114391

34. Bowyer PH, El-Haroun ER, Davies SJ. Dietary nucleotides enhance intestinal functional topography in European seabass (Dicentrarchus labrax). Aquacult Res 2019;20(7):1921-30. https://doi.org/10.1111/are.14078

35. Bowyer PH, El-Haroun ER, Salim HS, Davies SJ. Benefits of a commercial solid-state fermentation (SSF) product on growth performance, feed efficiency and gut morphology of juvenile Nile tilapia (Oreochromis niloticus) fed different UK lupin meal cultivars. Aquaculture 2020;523:735192. https://doi.org/10.1016/j.aquaculture.2020.735192

36. Li P, Mai K, Trushenski J, Wu G. New developments in fish amino acid nutrition: towards functional and environmentally oriented aquafeeds. Amino Acids.2009;37(1):43-53. https://doi.org/10.1007/s00726-008-0171-1

37. Lin SM, Shi CM, Mu MM, Chen YJ, Luo L. Effect of high dietary starch levels on growth, hepatic glucose metabolism, oxidative status and immune response of juvenile largemouth bass, Micropterus salmoides. Fish Shellfish Immunol 2018;78:121-6. https://doi.org/10.1016/j.fsi.2018.04.046

38. Vasconcelos TS, Thomaz MC, Castelini FR, Alvarenga PV, de Oliveira JA, Ramos GF, et al. Evaluation of pineapple byproduct at increasing levels in heavy finishing pigs feeding. Anim Feed Sci Technol 2020;269:114664. https://doi.org/10.1016/j.anifeedsci.2020.114664

39. Ribeiro L, Couto A, Olmedo M, Álvarez-Blázquez B, Linares F, Valente LM. Digestive enzyme activity at different developmental stages of blackspot seabream, Pagellus bogaraveo (Brunnich 1768). Aquacult Res 2008;39(4):339-46. https://doi.org/10.1111/j.1365-2109.2007.01684.x

40. Gómez-Limia L, Franco I, Blanco T, Martínez S. Changes in amino acids content in muscle of European Eel (Anguilla anguilla) in relation to body size. Int J Nutr Food Eng 2019;13(2):38-41.

41. Dawood MA, Koshio S, Esteban MÁ. Beneficial roles of feed additives as immunostimulants in aquaculture: a review. Rev Aquacult 2018;10(4):950-74. https://doi.org/10.1111/raq.12209

42. Jiang N, Tan NS, Ho B, Ding JL. Respiratory protein-generated reactive oxygen species as an antimicrobial strategy. Nat Immunol 2007;8(10):1114-22. https://doi.org/10.1038/ni1501

43. Sharma SA, Surveswaran S, Arulraj J, Velayudhannair K. Bromelain enhances digestibility of Spirulina-based fish feed. J Appl Phycol 2021;33(2):967-77. https://doi.org/10.1007/s10811-020-02337-4