Ulva and Gracilaria in finfish aquafeeds: standardisation, health effects and evidence for bacterial disease resistance
DOI:
https://doi.org/10.17017/j.fish.1435Keywords:
aquaculture, bacterial disease resistance, functional aquafeeds, Gracilaria, seaweed extracts, UlvaAbstract
Bacterial diseases remain a major constraint in intensive aquaculture and have increased interest in functional feed ingredients that can support fish health while reducing dependence on antimicrobials. The present review critically examined Ulva and Gracilaria derived meals, extracts and enriched fractions as functional aquafeed ingredients, with focus on the links between biomass origin, cultivation, processing, chemical composition and disease-related outcomes in finfish. Both genera provided nutritional components together with sulfated polysaccharides, phenolics, pigments, fatty acids and sterols that may act through direct antibacterial effects, redox regulation, innate immune modulation, maintenance of mucosal and intestinal barriers, and changes in the gut microbiota. However, the available evidence showed that efficacy was strongly product specific. Responses varied with seaweed species, production environment, extraction method, dietary dose, fish host and pathogen model. Studies in commercially important fishes, including seabass and tilapia, indicated that improved growth, immune responses or gut microbiota profiles did not necessarily demonstrate resistance to infection. Studies combining a chemically characterised product with dietary exposure and a controlled bacterial challenge provided stronger evidence. Major drawbacks include incomplete taxonomic authentication, poor reporting of extraction and feed-manufacturing conditions, limited chemical standardisation, short feeding periods and uneven pathogen coverage, particularly for gram-positive bacteria. Controlled cultivation and tissue culture may improve traceability and biomass consistency, but their functional advantages remain to be demonstrated. Progress therefore depends on converting variable seaweed preparations into safe, reproducible and chemically defined products whose efficacy is validated in the intended fish-pathogen system.
Downloads
References
Afonso C, Correia AP, Freitas MV, Mouga T, Baptista T (2021) In vitro evaluation of the antibacterial and antioxidant activities of extracts of Gracilaria gracilis with a view into its potential use as an additive in fish feed. Applied Sciences 11(14): 6642.
Baweja P, Sahoo D, García-Jiménez P, Robaina RR (2009) Seaweed tissue culture as applied to biotechnology: problems, achievements and prospects. Phycological Research 57(1): 45–58.
Bondad-Reantaso MG, Subasinghe RP, Arthur JR, Ogawa K, Chinabut S, ... Shariff M (2005) Disease and health management in Asian aquaculture. Veterinary Parasitology 132(3–4): 249–272.
Capillo G, Savoca S, Costa R, Sanfilippo M, Rizzo C, ... Faggio C (2018) New insights into the culture method and antibacterial potential of Gracilaria gracilis. Marine Drugs 16(12): 492.
Cotas J, Leandro A, Monteiro P, Pacheco D, Figueirinha A, ... Pereira L (2020) Seaweed phenolics: from extraction to applications. Marine Drugs 18(8): 384.
de Almeida CLF, Falcão HDS, Lima GRDM, Montenegro CDA, Lira NS, ... Batista LM (2011) Bioactivities from marine algae of the genus Gracilaria. International Journal of Molecular Sciences 12(7): 4550–4573.
Faisan JP Jr, Samson EJD, Sollesta-Pitogo HT, Dayrit R, Balinas VT, de la Peña LD (2024) Seasonal growth, carrageenan properties, and resistance to disease and epiphytic pests between Kappaphycus alvarezii var. tambalang tissue-cultured and farm-sourced seaweeds. Journal of Applied Phycology 36(3): 1377–1389.
García-Poza S, Morais T, Leandro A, Cotas J, Marques JC, ... Gonçalves AMM (2022) A comparative study of the fatty acids and monosaccharides of wild and cultivated Ulva sp. Journal of Marine Science and Engineering 10(2): 233.
Gonçalves AT, Simões M, Costa C, Passos R, Baptista T (2022) Modulatory effect of Gracilaria gracilis on European seabass gut microbiota community and its functionality. Scientific Reports 12: 14836.
Jiksing C, Ongkudon MM, Thien VY, Rodrigues KF, Yong WTL (2022) Recent advances in seaweed seedling production: a review of eucheumatoids and other valuable seaweeds. Algae 37(2): 105–121.
Kamble MT, Rudtanatip T, Soowannayan C, Nambunruang B, Medhe SV, Wongprasert K (2022) Depolymerized fractions of sulfated galactans extracted from Gracilaria fisheri and their antibacterial activity against Vibrio parahaemolyticus and Vibrio harveyi. Marine Drugs 20(8): 469.
Kasanah N, Amelia W, Mukminin A, Triyanto, Isnansetyo A (2019) Antibacterial activity of Indonesian red algae Gracilaria edulis against bacterial fish pathogens and characterization of active fractions. Natural Product Research 33(22): 3303–3307.
Klongklaew N, Tansutaphanit S, Tiewpair P, Buncharoen W, Phaksopa J, ... Uchuwittayakul A (2025) Fish health enhancement and intestinal microbiota benefits of Asian seabass (Lates calcarifer Bloch, 1790) on dietary sea lettuce (Ulva rigida C. Agardh, 1823) extract supplementation. Animals 15(12): 1714.
Lahaye M, Robic A (2007) Structure and functional properties of ulvan, a polysaccharide from green seaweeds. Biomacromolecules 8(6): 1765–1774.
Lomartire S, Gonçalves AMM (2022) An overview of potential seaweed-derived bioactive compounds for pharmaceutical applications. Marine Drugs 20(2): 141.
Lu WJ, Tsui YC, Chang CJ, Hsu PH, Huang MY, ... Lin HTV (2022) Characterization and potentiating effects of the ethanolic extracts of the red seaweed Gracillaria sp. on the activity of carbenicillin against vibrios. ACS Omega 7(50): 46486–46493.
Madibana MJ, Mlambo V, Lewis B, Fouché C (2017) Effect of graded levels of dietary seaweed (Ulva sp.) on growth, hematological and serum biochemical parameters in dusky kob, Argyrosomus japonicus, Sciaenidae. Egyptian Journal of Aquatic Research 43: 249–254.
Matos GS, Pereira SG, Genisheva ZA, Gomes AM, Teixeira JA, Rocha CMR (2021) Advances in extraction methods to recover added-value compounds from seaweeds: sustainability and functionality. Foods 10(3): 516.
Pappou S, Dardavila MM, Savvidou MG, Louli V, Magoulas K, Voutsas E (2022) Extraction of bioactive compounds from Ulva lactuca. Applied Sciences 12(4): 2117.
Peixoto MJ, Ferraz R, Magnoni LJ, Pereira R, Gonçalves JF, ... Ozório ROA (2019) Protective effects of seaweed supplemented diet on antioxidant and immune responses in European seabass (Dicentrarchus labrax) subjected to bacterial infection. Scientific Reports 9: 16134.
Petit J, van den Brink E, Collén PN, Haenen OLM, Schrama J, Wiegertjes GF (2024) Green and red macroalgae extracts show antibacterial effects and induce innate immune responses in Nile tilapia and rainbow trout in-vitro. Comparative Immunology Reports 6: 200128.
Priyatharshni A, Antony C, Uma A, Ahilan B, Chidambaram P, ... Prabu E (2024) Effect of dietary seaweed supplementation on physiological responses of genetically improved farmed tilapia. Indian Journal of Animal Research 58(4): 607–614.
Purwaningsih S, Ramadhan W, Nabila WT, Deskawati E, Baabud HM (2024) Dataset on the chemical composition and bioactive compound of estuarine seaweed Gracilaria from four different cultivation area in Java and Lombok Island, Indonesia. Data in Brief 56: 110825.
Quitério E, Grosso C, Ferraz R, Delerue-Matos C, Soares C (2022) A critical comparison of the advanced extraction techniques applied to obtain health-promoting compounds from seaweeds. Marine Drugs 20(11): 677.
Rejeki S, Ariyati RW, Widowati LL, Bosma RH (2018) The effect of three cultivation methods and two seedling types on growth, agar content and gel strength of Gracilaria verrucosa. Egyptian Journal of Aquatic Research 44(1): 65–70.
Reverter M, Bontemps N, Lecchini D, Banaigs B, Sasal P (2014) Use of plant extracts in fish aquaculture as an alternative to chemotherapy: current status and future perspectives. Aquaculture 433: 50–61.
Rico A, Phu TM, Satapornvanit K, Min J, Shahabuddin AM, ... Van den Brink PJ (2013) Use of veterinary medicines, feed additives and probiotics in four major internationally traded aquaculture species farmed in Asia. Aquaculture 412–413: 231–243.
Robertson-Andersson DV, Wilson DT, Bolton JJ, Anderson RJ, Maneveldt GW (2009) Rapid assessment of tissue nitrogen in cultivated Gracilaria gracilis (Rhodophyta) and Ulva lactuca (Chlorophyta). African Journal of Aquatic Science 34(2): 169–172.
Roleda MY, Lage S, Aluwini DF, Rebours C, Brurberg MB, ... Gentili FG (2021) Chemical profiling of the Arctic sea lettuce Ulva fenestrata (Chlorophyta) mass-cultivated on land under controlled conditions for food applications. Food Chemistry 341: 127999.
Rorrer GL, Mullikin RK, Huang B, Gerwick WH, Maliakal S, Cheney DP (1999) Production of bioactive metabolites by cell and tissue cultures of marine macroalgae in bioreactor systems (pp. 165–184). In: Fu TJ, Singh G, Curtis WR (Eds) Plant cell and tissue culture for the production of food ingredients. Springer, Boston.
Safavi SV, Kenari AA, Tabarsa M, Esmaeili N (2019) Effect of sulfated polysaccharides extracted from marine macroalgae (Ulva intestinalis and Gracilariopsis persica) on growth performance, fatty acid profile, and immune response of rainbow trout (Oncorhynchus mykiss). Journal of Applied Phycology 31(6): 4021–4035.
Seyedalhosseini SH, Salati AP, Torfi Mozanzadeh M, Parrish CC, Shahriari A, Ahangarzadeh M (2024) Effect of dietary seaweed (Gracilaria pulvinata and Sargassum ilicifolium) on serum and mucosal immunity, some growth and immune-related genes expression, antioxidant status, and fatty acid profile in Asian seabass (Lates calcarifer). Aquaculture Nutrition 2024: 3683163.
Siddik MAB, Francis P, Foysal MJ, Francis DS (2024) Dietary seaweed extract mitigates oxidative stress in Nile tilapia by modulating inflammatory response and gut microbiota. Frontiers in Immunology 15: 1471261.
Siddik MAB, Francis P, Rohani MF, Azam MS, Mock TS, Francis DS (2023) Seaweed and seaweed-based functional metabolites as potential modulators of growth, immune and antioxidant responses, and gut microbiota in fish. Antioxidants 12(12): 2066.
Sotoudeh E, Jafari M (2017) Effects of dietary supplementation with red seaweed, Gracilaria pygmaea, on growth, carcass composition and hematology of juvenile rainbow trout, Oncorhynchus mykiss. Aquaculture International 25: 1857–1867.
Stentiford GD, Sritunyalucksana K, Flegel TW, Williams BA, Withyachumnarnkul B, ... Bass D (2017) New paradigms to help solve the global aquaculture disease crisis. PLOS Pathogens 13(2): e1006160.
Sudrajat AO, Tarigan N, Arfah H, Alimuddin, Wahjuningrum D (2025) The effects of suplementation of Ulva reticulata extract on growth-related parameters and hematological profile of the red tilapia (Oreochromis sp.). Egyptian Journal of Aquatic Biology and Fisheries 29(1): 2263–2279.
Thanigaivel S, Chandrasekaran N, Mukherjee A, Thomas J (2019) Protective efficacy of microencapsulated seaweed extracts for preventing Aeromonas infections in Oreochromis mossambicus. Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology 218: 36–45.
Thépot V, Campbell AH, Rimmer MA, Paul NA (2021) Meta-analysis of the use of seaweeds and their extracts as immunostimulants for fish: a systematic review. Reviews in Aquaculture 13(2): 907–933.
Vargas-Murga L, Dürrani Ö, Adams J, Steinhagen S, Turan G, ... Shpigel M (2025) Metal(oid)s in Ulva: should we be worried? Food Chemistry 493: 145941.
Vatsos IN, Rebours C (2015) Seaweed extracts as antimicrobial agents in aquaculture. Journal of Applied Phycology 27(5): 2017–2035.
Vizcaíno AJ, Fumanal M, Sáez MI, Martínez TF, Moriñigo MA, ... Alarcón FJ (2019) Evaluation of Ulva ohnoi as functional dietary ingredient in juvenile Senegalese sole (Solea senegalensis): effects on the structure and functionality of the intestinal mucosa. Algal Research 42: 101608.
Downloads
Published
Data Availability Statement
Data sharing is not applicable to this article because no new datasets were generated or analysed in this review.
Issue
Section
License
Copyright (c) 2026 Navin Kumar D., Saravanan S., Kaviarasu D., Ezhilarasi V., Sathish Kumar T., Porselvan S., Santhiya V., Dhinesh P.
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
