Early mild stress (EMS) is like preparedness and might help fish deal with stress appropriately. This study investigated how EMS and photoperiod changes can impact growth, haematology, blood biochemistry, immunological response, antioxidant system, liver enzymes, and stress response of oscar (Astronotus ocellatus; 7.29 ± 0.96 g) before and after acute confinement stress (AC stress). Ten experimental treatments included five different photoperiods 8L16D (08:16 light to dark), 12L12D (12:12 light to dark), 16L8D (16:08 light to dark), 20L4D (20:04 light to dark), and 24L0D (24:00 light to dark), and these five photoperiod schedules were conducted in an EMS condition. After 9 weeks, no significant differences were found in growth parameters, survival rate, and body composition. At the end of the experiment and after AC stress, fish farmed in 24 light hours had the lowest haematocrit, white blood cells, total protein, blood performance, lysozyme, immunoglobulin M, complement C3, superoxide dismutase, and catalase. Fish that experienced EMS had significantly higher survival rates than those farmed in normal conditions (80.67% vs 61.33%). In conclusion, considering all measured parameters, 8-h light can be suggested as an optimum photoperiod for this fish species. Under 24L0D (no EMS) conditions, there were many negative effects apparent. In addition, a positive effect of EMS was evident in terms of survival after AC stress. AC stress decreased some health parameters under 24-h light treatment, while these results were not observed in EMS-exposed fish. Therefore, the EMS schedule can be a useful tool in preventing the negative effects of stress.

CSIRO Agriculture and Food Livestock and Aquaculture Program Bribie Island Research Centre Bribie Island QLD Australia

Department of Fisheries Faculty of Marine Science Tarbiat Modares University Noor Iran

Department of Microbiology Pathobiology and Basic Sciences Faculty of Veterinary Medicine Razi University Kermanshah Iran

Faculty of Fisheries and Protection of Waters South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses Institute of Aquaculture and Protection of Waters University of South Bohemia in České Budějovice Na Sádkách České Budějovice Czech Republic

Institute for Marine and Antarctic Studies University of Tasmania 15 21 Nubeena Cres Hobart Taroona TAS 7053 Australia

Nelson Marlborough Institute of Technology 322 Hardy Street Private Bag 19 Nelson New Zealand

Nutrition and Seafood Laboratory School of Life and Environmental Sciences Deakin University Geelong VIC 3225 Australia

Zobrazit více v PubMed

Abdollahpour H, Falahatkar B, Lawrence C (2020) The effect of photoperiod on growth and spawning performance of zebrafish, Danio Rerio. Aquac Rep 17:100295. https://doi.org/10.1016/j.aqrep.2020.100295 DOI

Adam ML, Torres MFP, Franci AC, Sponchiado G, Torres RA, Correia MTDS (2011) On the stress by photoperiod, temperature and noise as possible causes of genomic damaging in an animal model. Stress Health 27:e152–e156. https://doi.org/10.1002/smi.1350 DOI

Ahmadi-Noorbakhsh S, Mirabzadeh Ardakani E, Sadighi J, Aldavood SJ, Farajli Abbasi M, Farzad-Mohajeri S, Ghasemi A, Sharif-Paghaleh E, Hatami Z, Nikravanfard N (2021) Guideline for the care and use of laboratory animals in Iran. Lab Anim 50:303–305. https://doi.org/10.1038/s41684-021-00871-3 DOI

Akhtar M, Rajesh M, Kamalam B, Ciji A (2020) Effect of photoperiod and temperature on indicators of immunity and wellbeing of endangered golden mahseer (Tor putitora) broodstock. J Therm Biol 93:102694. https://doi.org/10.1016/j.jtherbio.2020.102694 PubMed DOI

Almazán-Rueda P, Van Helmond AM, Verreth J, Schrama J (2005) Photoperiod affects growth, behaviour and stress variables in Clarias gariepinus. J Fish Biol 67:1029–1039. https://doi.org/10.1111/j.0022-1112.2005.00806.x DOI

Amar EC, Kiron V, Satoh S, Okamoto N, Watanabe T (2000) Effects of dietary β-carotene on the immune response of rainbow trout Oncorhynchus mykiss. Fish Sci 66:1068–1075. https://doi.org/10.1046/j.1444-2906.2000.00170.x DOI

Ángeles Esteban M, Cuesta A, Rodríguez A, Meseguer J (2006) Effect of photoperiod on the fish innate immune system: a link between fish pineal gland and the immune system. J Pineal Res 41:261–266. https://doi.org/10.1111/j.1600-079X.2006.00362.x PubMed DOI

AOAC (2000) Official methods of analysis of the AOAC International Vol. 18. The Association

Asgari M, Abedian Kenari A, Esmaeili N, Rombenso A (2020) Effects of hydroalcoholic extract of honeybee pollen on growth performance, flesh quality, and immune and stress response response of rainbow trout (Oncorhynchus mykiss). Aquac Nutr 26:1505–1519. https://doi.org/10.1111/anu.13098 DOI

Atwood H, Tomasso J, Webb K, Gatlin Iii D (2003) Low-temperature tolerance of Nile tilapia, Oreochromis niloticus: effects of environmental and dietary factors. Aquac Res 34:241–251. https://doi.org/10.1046/j.1365-2109.2003.00811.x DOI

Auperin B, Geslin M (2008) Plasma cortisol response to stress in juvenile rainbow trout is influenced by their life history during early development and by egg cortisol content. Gen Comp Endocrinol 158:234–239. https://doi.org/10.1016/j.ygcen.2008.07.002 PubMed DOI

Bae Y-S, Shin E-C, Bae Y-S, Van Eden W (2019) Frontiers Media SA 10:245. https://doi.org/10.3389/fimmu.2019.00245

Bani A, Tabarsa M, Falahatkar B, Banan A (2009) Effects of different photoperiods on growth, stress and haematological parameters in juvenile great sturgeon Huso huso. Aquac Res 40:1899–1907. https://doi.org/10.1111/j.1365-2109.2009.02321.x DOI

Barlow C, Pearce M, Rodgers L, Clayton P (1995) Effects of photoperiod on growth, survival and feeding periodicity of larval and juvenile barramundi Lates calcarifer (Bloch). Aquac 138:159–168. https://doi.org/10.1016/0044-8486(95)01073-4 DOI

Biswas A, Maita M, Yoshizaki G, Takeuchi T (2004) Physiological responses in Nile tilapia exposed to different photoperiod regimes. J Fish Biol 65:811–821. https://doi.org/10.1111/j.0022-1112.2004.00487.x DOI

Biswas AK, Seoka M, Takii K, Maita M, Kumai H (2006a) Stress response of red sea bream Pagrus major to acute handling and chronic photoperiod manipulation. Aquac 252:566–572. https://doi.org/10.1016/j.aquaculture.2005.06.043 DOI

Biswas AK, Seoka M, Tanaka Y, Takii K, Kumai H (2006b) Effect of photoperiod manipulation on the growth performance and stress response of juvenile red sea bream (Pagrus major). Aquac 258:350–356. https://doi.org/10.1016/j.aquaculture.2006.03.048 DOI

Biswas AK, Seoka M, Ueno K, Takii K, Kumai H (2008) Stimulation of growth performance without causing stress response in young red sea bream, Pagrus major (Temminck & Schlegel), by photoperiod manipulation. Aquac Res 39:457–463. https://doi.org/10.1111/j.1365-2109.2008.01897.x DOI

Biswas A, Seoka M, Inagaki H, Takii K (2010) Reproduction, growth and stress response in adult red sea bream, Pagrus major (Temminck & Schlegel) exposed to different photoperiods at spawning season. Aquac Res 41:519–527. https://doi.org/10.1111/j.1365-2109.2009.02341.x DOI

Biswas A, Takaoka O, Kumai H, Takii K (2016) Combined effect of photoperiod and self-feeder on the growth performance of striped knifejaw, Oplegnathus fasciatus. Aquac 452:183–187. https://doi.org/10.1016/j.aquaculture.2015.10.038 DOI

Boeuf G & Falcon J (2001) Photoperiod and growth in fish. Vie et Milieu/Life & Environ 247–266

Bowden T, Butler R, Bricknell I (2004) Seasonal variation of serum lysozyme levels in Atlantic halibut (Hippoglossus hippoglossus L.). Fish Shellfish Immunol 17:129–135. https://doi.org/10.1016/j.fsi.2003.12.001 PubMed DOI

Burgos A, Valenzuela A, Gonzalez M, Klempau A (2004) Nonspecific defence mechanisms of rainbow trout (Oncorhynchus mykiss) during artificial photoperiod. Bull Eur Assoc Fish Pathol 24:240–245

Ceballos-Francisco D, Cuesta A, Esteban MÁ (2020) Effect of light–dark cycle on skin mucosal immune activities of gilthead seabream (Sparus aurata) and European sea bass (Dicentrarchus labrax). Fishes 5:10. https://doi.org/10.3390/fishes5010010 DOI

Clerton P, Troutaud D, Verlhac V, Gabaudan J, Deschaux P (2001) Dietary vitamin E and rainbow trout (Oncorhynchus mykiss) phagocyte functions: effect on gut and on head kidney leucocytes. Fish Shellfish Immunol 11:1–13. https://doi.org/10.1006/fsim.2000.0287 PubMed DOI

Davis KB, Mcentire M (2006) Effect of photoperiod on feeding, intraperitoneal fat, and insulin-like growth factor-I in sunshine bass. J World Aquaculture Soc 37:431–436. https://doi.org/10.1111/j.1749-7345.2006.00056.x DOI

Dawood MA, Gewaily MS, Monier MN, Younis EM, Van Doan H, Sewilam H (2021) The regulatory roles of yucca extract on the growth rate, hepato-renal function, histopathological alterations, and immune-related genes in common carp exposed with acute ammonia stress. Aquac 534:736287. https://doi.org/10.1016/j.aquaculture.2020.736287 DOI

Di Z, Li K, Li T, Yan L, Jiang H, Liu L (2023) Effects of light intensity and photoperiod on the growth performance of juvenile Murray cods (Maccullochella peelii) in recirculating aquaculture system (RAS). Aquac Fish 8:274–279. https://doi.org/10.1016/j.aaf.2021.12.009 DOI

Ellis T, Yildiz HY, López-Olmeda SMT, Tort L, Øverli Ø, Martins CIM (2012) Cortisol and finfish welfare. Fish Physiol Biochem 38:163–188. https://doi.org/10.1007/s10695-011-9568-y PubMed DOI

El-Sayed A-FM, Kawanna M (2004) Effects of photoperiod on the performance of farmed Nile tilapia Oreochromis niloticus: I. Growth, feed sutilisation efficiency and survival of fry and fingerlings. Aquac 231:393–402. https://doi.org/10.1016/j.aquaculture.2003.11.012 DOI

Esmaeili N (2021) Blood performance: a new formula for fish growth and health. Biology 10:1236. https://doi.org/10.3390/biology10121236 PubMed DOI PMC

Esmaeili N, Abedian Kenari A, Rombenso A (2017) Immunohematological status under acute ammonia stress of juvenile rainbow trout (Oncorhynchus mykiss Walbaum, 1792) fed garlic (Allium sativum) powder-supplemented meat and bone meal-based feeds. Comp Clin Pathol 26:853–866. https://doi.org/10.1007/s00580-017-2457-8 DOI

Esmaeili N, Hosseini H, Zare M, Akhavan SR, Rombenso A (2022) Early mild stress along with lipid improves the stress responsiveness of oscar (Astronotus ocellatus). Aquac Nutr 8991678 https://doi.org/10.1155/2022/8991678

Esmaeili N, Zare M, Choupani SMH, Kazempour M, Hosseini H, Akhavan S & Salini M (2024) Immunohaemtalogical changes of oscar (Astronotus ocellatus) in response to temperature and early mild stress. Fish Shellfish Immunol

Falahatkar B, Poursaeid S, Efatpanah I, Meknatkhah B, Biswas A (2012) Effect of photoperiod manipulation on growth performance, physiological and hematological indices in juvenile Persian sturgeon, Acipenser persicus. J World Aquac Soc 43:679–687. https://doi.org/10.1111/j.1749-7345.2012.00600.x DOI

Fang Y, Chan VK, Hines CW, Stiller KT, Richards JG, Brauner CJ (2019) The effects of salinity and photoperiod on aerobic scope, hypoxia tolerance and swimming performance of coho salmon (Oncorhynchus kisutch) reared in recirculating aquaculture systems. Comp Biochem Physiol a: Mol Integr Physiol 231:82–90. https://doi.org/10.1016/j.cbpa.2019.01.026 PubMed DOI

Gao XQ, Fei F, Huang B, Meng XS, Zhang T, Zhao K, Chen H, Xing R, Liu B (2021) Alterations in hematological and biochemical parameters, oxidative stress, and immune response in Takifugu rubripes under acute ammonia exposure. Comp Biochem Physiol c: Toxicol Pharmacol 243:108978. https://doi.org/10.1016/j.cbpc.2021.108978 PubMed DOI

Ghosi Mobaraki MR, Abedian Kenari A, Bahrami Gorji S, Esmaeili N (2020) Effect of dietary fish and vegetable oil on the growth performance, body composition, fatty acids profile, reproductive performance and larval resistance in pearl gourami (Trichogaster leeri). Aquac Nutr 26:894–907. https://doi.org/10.1111/anu.13048 DOI

Ginés R, Afonso JM, Argüello A, Zamorano MJ, López JL (2004) The effects of long-day photoperiod on growth, body composition and skin colour in immature gilthead sea bream (Sparus aurata L.). Aquac Res 35:1207–1212. https://doi.org/10.1111/j.1365-2109.2004.01126.x DOI

Guo BY, Li W, Chen J (2010) Influence of nutrient density and lighting regime in broiler chickens: effect on antioxidant status and immune function. Br Poult Sci 51:222–228. https://doi.org/10.1080/00071661003746503 PubMed DOI

Hansen T, Stefansson S, Taranger G (1992) Growth and sexual maturation in Atlantic salmon, Salmon salar L., reared in sea cages at two different light regimes. Aquac Res 23:275–280. https://doi.org/10.1111/j.1365-2109.1992.tb00770.x DOI

Harrington RW Jr (1956) An experiment on the effects of contrasting daily photoperiods on gametogenesis and reproduction in the centrarchid fish, Enneacanthus obesus (Girard). J Exp Zool 131:203–223. https://doi.org/10.1002/jez.1401310302 DOI

Hoseini SM, Gupta SK, Yousefi M, Kulikov EV, Drukovsky SG, Petrov AK, Mirghaed AT, Hoseinifar SH, Van Doan H (2022) Mitigation of transportation stress in common carp, Cyprinus carpio, by dietary administration of turmeric. Aquaculture 564:737380. https://doi.org/10.1016/j.aquaculture.2021.737380 DOI

Hoseinifar SH, Yousefi S, Van Doan H, Ashouri G, Gioacchini G, Maradonna F, Carnevali O (2020) Oxidative stress and antioxidant defense in fish: the implications of probiotic, prebiotic, and synbiotics. Rev Fish Sci Aquac 29:198–217. https://doi.org/10.1080/23308249.2020.1795616 DOI

Hosseini H, Esmaeili N, Zare M, Rombenso A (2021) Egg enrichment with n-3 fatty acids in farmed hens in sub-optimum temperature: a cold-temperament additive mix alleviates adverse effects of stress on performance and health. J Anim Physiol Anim Nutr. https://doi.org/10.1111/jpn.13659 DOI

Hosseini H, Pooyanmehr M, Foroughi A, Esmaeili N, Ghiasi F, Lorestany R (2022) Remarkable positive effects of figwort (Scrophularia striata) on improving growth performance, and immunohematological parameters of fish. Fish Shellfish Immunol 120:111–121. https://doi.org/10.1016/j.fsi.2021.11.020 PubMed DOI

Hosseinpour Aghaei R, Abedian Kenari A, Yazdani Sadati MA, Esmaeili N (2018) The effect of time-dependent protein restriction on growth factors, nonspecific immunity, body composition, fatty acids and amino acids in the Siberian sturgeon (Acipenser baerii). Aquac Res 49:3033–3044. https://doi.org/10.1111/are.13764 DOI

Hvas M (2022) Influence of photoperiod and protocol length on metabolic rate traits in ballan wrasse Labrus bergylta. J Fish Biol 100:687–696. https://doi.org/10.1111/jfb.14981 PubMed DOI

Imsland AK, Folkvord A, Stefansson S (1995) Growth, oxygen consumption and activity of juvenile turbot (Scophthalmus maximus L.) reared under different temperatures and photoperiods. Neth J Sea Res 34:149–159. https://doi.org/10.1016/0077-7579(95)90023-3 DOI

Kenari AA, Mahmoudi N, Soltani M, Abediankenari S (2013) Dietary nucleotide supplements influence the growth, haemato-immunological parameters and stress responses in endangered Caspian brown trout (Salmo trutta caspius Kessler, 1877). Aquac Nutr 19:54–63. https://doi.org/10.1111/j.1365-2095.2012.00938.x DOI

Kitagawa AT, Costa LS, Paulino RR, Luz RK, Rosa PV, Guerra-Santos B, Fortes-Silva R (2015) Feeding behavior and the effect of photoperiod on the performance and hematological parameters of the pacamã catfish (Lophiosilurus alexandri). Appl Anim Behav Sci 171:211–218. https://doi.org/10.1016/j.applanim.2015.08.025 DOI

Li X, Wei P, Liu S, Tian Y, Ma H, Liu Y (2021) Photoperiods affect growth, food intake and physiological metabolism of juvenile European sea bass (Dicentrachus labrax L.). Aquac Rep 20:100656 https://doi.org/10.1016/j.aqrep.2021.100656

Liu F, Shi H-Z, Guo Q-S, Yu Y-B, Wang A-M, Lv F, Shen W-B (2016) Effects of astaxanthin and emodin on the growth, stress resistance and disease resistance of yellow catfish (Pelteobagrus fulvidraco). Fish Shellfish Immunol 51:125–135. https://doi.org/10.1016/j.fsi.2016.02.020 PubMed DOI

Ma H, Wei P, Li X, Liu S, Tian Y, Zhang Q, Liu Y (2021) Effects of photoperiod on growth, digestive, metabolic and non-special immunity enzymes of Takifugu rubripes larvae. Aquaculture 542:736840. https://doi.org/10.1016/j.aquaculture.2021.736840 DOI

Machado MRF, De Andrade EA, De Souza Andrade E, De Jesus Paula DA, Oliveira JA, Costa AC, Peconick AP & Murgas LDS (2016) Influence of photoperiod over morphometric and hematological parameters of juvenile piracanjubas (Brycon orbygnianus). J Agric Sci Technol B 6:350–359 https://doi.org/10.17265/2161-6264/2016.05.009

Madaro A, Olsen RE, Kristiansen TS, Ebbesson LO, Nilsen TO, Flik G, Gorissen M (2015) Stress in Atlantic salmon: response to unpredictable chronic stress. J Exp Biol 218:2538–2550. https://doi.org/10.1242/jeb.120535 PubMed DOI

Malambugi A, Yu Z, Zhu W, Wang L, Song F, Limbu SM, Dong Z (2020) Effects of photoperiod on growth performance and melanogenesis pathway for skin pigmentation of Malaysian red tilapia. Aquac Res 51:1824–1833. https://doi.org/10.1111/are.14531 DOI

Malinovskyi O, Rahimnejad S, Stejskal V, Boňko D, Stará A, Velíšek J, Policar T (2022) Effects of different photoperiods on growth performance and health status of largemouth bass (Micropterus salmoides) juveniles. Aquaculture 548:737631. https://doi.org/10.1016/j.aquaculture.2021.737631 DOI

Martínez-Álvarez RM, Morales AE, Sanz A (2005) Antioxidant defenses in fish: biotic and abiotic factors. Rev Fish Biol Fisheries 15:75–88. https://doi.org/10.1007/s11160-005-7846-4 DOI

Martos-Sitcha JA, Mancera JM, Prunet P & Magnoni LJ (2020) Frontiers Media SA 11:162 https://doi.org/10.3389/fphys.2020.00162

Montazeri H, Abedian Kenari A, Esmaeili N (2021) Soybean-based diets plus probiotics improve the profile of fatty acids, digestibility, intestinal microflora, growth performance, and the innate immunity of beluga (Huso huso). Aquac Res 52:152–166. https://doi.org/10.1111/are.14877 DOI

Mukherjee A, Haldar C (2015) Effect of 2-deoxy-d-glucose induced metabolic stress on testicular steroidogenesis and antioxidant status in golden hamster, Mesocricetus auratus: role of photoperiod. J Photochem Photobiol, B 153:40–50. https://doi.org/10.1016/j.jphotobiol.2015.09.004 PubMed DOI

Nelson RJ, Demas GE (1996) Seasonal changes in immune function. Q Rev Biol 71:511–548. https://doi.org/10.1086/419555 PubMed DOI

Park SH, Kim IG, Kim HC, Gang MJ, Son SE, Lee HJ (2015) Influence of various photoperiods on stress hormone production, immune function, and hematological parameters in ICR mice. Korean J Vet Res 55:111–116 https://doi.org/10.14405/kjvr.2015.55.2.111

Pederzoli A, Mola L (2016) The early stress responses in fish larvae. Acta Histochem 118:443–449. https://doi.org/10.1016/j.acthis.2016.03.001 PubMed DOI

Pereira LAL, Amanajás RD, De Oliveira AM, Da Silva MDNP, Val AL (2021) Health of the Amazonian fish tambaqui (Colossoma macropomum): effects of prolonged photoperiod and high temperature. Aquac 541:736836. https://doi.org/10.1016/j.aquaculture.2021.736836 DOI

Pourhosein Sarameh S, Falahatkar B, Azari Takami G, Efatpanah I (2013) Physiological changes in male and female pikeperch Sander lucioperca (Linnaeus, 1758) subjected to different photoperiods and handling stress during the reproductive season. Fish Physiol Biochem 39:1253–1266. https://doi.org/10.1007/s10695-013-9780-z DOI

Purchase C, Boyce D, Brown J (2000) Growth and survival of juvenile yellowtail flounder Pleuronectes ferrugineus (Storer) under different photoperiods. Aquac Res 31:547–552. https://doi.org/10.1046/j.1365-2109.2000.00480.x DOI

Ravardshiri M, Bahram S, Javadian SR, Bahrekazemi M (2021) Cinnamon promotes growth performance, digestive enzyme, blood parameters, and antioxidant activity of rainbow trout (Oncorhynchus mykiss) in low-carbohydrate diets. Turk J Fish Aquat Sci 21:309–322. https://doi.org/10.4194/1303-2712-v21_7_01 DOI

Reddy P, Leatherland J (2003) Influences of photoperiod and alternate days of feeding on plasma growth hormone and thyroid hormone levels in juvenile rainbow trout. J Fish Biol 63:197–212. https://doi.org/10.1046/j.1095-8649.2003.00144.x DOI

Řehulka J, Minařík B, Řehulková E (2004) Red blood cell indices of rainbow trout Oncorhynchus mykiss (Walbaum) in aquaculture. Aquac Res 35:529–546. https://doi.org/10.1111/j.1365-2109.2004.01035.x DOI

Reiter RJ (2003) Melatonin: clinical relevance. Best Pract Res Clin Endocrinol Metab 17:273–285. https://doi.org/10.1016/S1521-690X(03)00016-2 PubMed DOI

Ren X, Zhang J, Wang L, Wang Z, Wang Y (2020) Diel variation in cortisol, glucose, lactic acid and antioxidant system of black sea bass Centropristis striata under natural photoperiod. Chronobiol Int 37:176–188. https://doi.org/10.1080/07420528.2019.1675684 PubMed DOI

Ruchin A (2006) Effect of light on white blood cell count in carp Cyprinus carpio L. Biology Bulletin 33:517–520. https://doi.org/10.1134/S1062359006050153 DOI

Safavi SV, Abedian Kenari A, 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). J Appl Phycol 31:4021–4035. https://doi.org/10.1007/s10811-019-01902-w DOI

Shearer KD (1994) Factors affecting the proximate composition of cultured fishes with emphasis on salmonids. Aquac 119:63–88. https://doi.org/10.1016/0044-8486(94)90444-8 DOI

Shin KW, Kim SH, Kim JH, Hwang SD, Kan JC (2016) Toxic effects of ammonia exposure on growth performance, hematological parameters, and plasma components in rockfish, Sebastes schlegelii, during thermal stress. Fish Aquat Sci 19:44. https://doi.org/10.1186/s41240-016-0044-6 DOI

Stickney RR, Andrews JW (1971) The influence of photoperiod on growth and food conversion of channel catfish. The Progressive Fish-Culturist 33:204–205. https://doi.org/10.1577/1548-8640(1971)33[204:TIOPOG]2.0.CO;2 DOI

Sun Z, Tan X, Liu Q, Ye H, Zou C, Xu M, Zhang Y, Ye C (2019) Physiological, immune responses and liver lipid metabolism of orange-spotted grouper (Epinephelus coioides) under cold stress. Aquac 498:545–555. https://doi.org/10.1016/j.aquaculture.2018.08.051 DOI

Tazikeh T, Abedian Kenari A, Esmaeili N (2020) Effects of fish meal replacement by meat and bone meal supplemented with garlic (Allium sativum) powder on biological indices, feeding, muscle composition, fatty acid and amino acid profiles of whiteleg shrimp (Litopenaeus vannamei). Aquac Res 51:674–686. https://doi.org/10.1111/are.14416 DOI

Tejpal C, Pal A, Sahu N, Kumar JA, Muthappa N, Vidya S, Rajan M (2009) Dietary supplementation of L-tryptophan mitigates crowding stress and augments the growth in Cirrhinus mrigala fingerlings. Aquac 293:272–277. https://doi.org/10.1016/j.aquaculture.2008.09.014 DOI

Tian H, Zhang D, Li X, Jiang G, Liu W (2019) Photoperiod affects blunt snout bream (Megalobrama amblycephala) growth, diel rhythm of cortisol, activities of antioxidant enzymes and mRNA expression of GH/IGF-I. Comp Biochem Physiol b: Biochem Mol Biol 233:4–10. https://doi.org/10.1016/j.cbpb.2019.03.007 PubMed DOI

Valenzuela AE, Silva VM, Klempau AE (2006) Effects of constant light on haematological parameters of cultured rainbow trout (Oncorhynchus mykiss) in the Southern Hemisphere. Fish Physiol Biochem 32:113–120. https://doi.org/10.1007/s10695-006-9103-8 DOI

Valenzuela A, Rodríguez I, Schulz B, Cortés R, Acosta J, Campos V, Escobar-Aguirre S (2022) Effects of Continuous Light (LD24: 0) Modulate the expression of lysozyme, mucin and peripheral blood cells in rainbow trout. Fishes 7:28. https://doi.org/10.3390/fishes7010028 DOI

Vera Cruz E, Brown C (2009) Influence of the photoperiod on growth rate and insulin-like growth factor-I gene expression in Nile tilapia Oreochromis niloticus. J Fish Biol 75:130–141. https://doi.org/10.1111/j.1095-8649.2009.02271.x DOI

Vindas MA, Madaro A, Fraser TW, Höglund E, Olsen RE, Øverli Ø, Kristiansen TS (2016) Coping with a changing environment: the effects of early life stress. R Soc Open Sci 3:160382. https://doi.org/10.1098/rsos.160382 PubMed DOI PMC

Vindas MA, Fokos S, Pavlidis M, Höglund E, Dionysopoulou S, Ebbesson LOE, Papandroulakis N, Dermon CR (2018) Early life stress induces long-term changes in limbic areas of a teleost fish: the role of catecholamine systems in stress coping. Sci Rep 8:5638. https://doi.org/10.1038/s41598-018-23950-x PubMed DOI PMC

Walton JC, Weil ZM, Nelson RJ (2011) Influence of photoperiod on hormones, behavior, and immune function. Front Neuroendocrinol 32:303–319. https://doi.org/10.1016/j.yfrne.2010.12.003 PubMed DOI

Wang K, Li K, Liu L, Tanase C, Mols R, Van Der Meer M (2023) Effects of light intensity and photoperiod on the growth and stress response of juvenile Nile tilapia (Oreochromis niloticus) in a recirculating aquaculture system. Aquaculture and Fisheries 8:85–90. https://doi.org/10.1016/j.aaf.2020.03.001 DOI

Wei H, Cai W-J, Liu H-K, Han D, Zhu X-M, Yang Y-X, Jin J-Y, Xie S-Q (2019) Effects of photoperiod on growth, lipid metabolism and oxidative stress of juvenile gibel carp (Carassius auratus). J Photochem Photobiol, B 198:111552. https://doi.org/10.1016/j.jphotobiol.2019.111552 PubMed DOI

Windarti W, Amin B & Simarmata AH (2021) Growth and health status of Pangasionodon hypophthalmus reared under manipulated photoperiod conditions. F1000Res 10 https://doi.org/10.12688/f1000research.28259.1

Wintrobe M (1929) The volume and hemoglobin content of the red blood corpuscle: simple method of calculation, normal findings, and value of such calculations in the anemias. Am J Med Sci 177:513–522. https://doi.org/10.1097/00000441-192904000-00006 DOI

Zare M, Esmaeili N, Hosseini H, Choupani SMH, Akhavan S, Rombenso A (2023a) Fish meal replacement and early mild stress improve stress responsiveness of oscar (Astronotus ocellatus) in future stressful events. Animals 13:1314. https://doi.org/10.3390/ani13081314 PubMed DOI PMC

Zare M, Heidari E, Choupani SMH, Akhavan S, Rombenso A, Esmaeili N (2023b) The recovery time between early mild stress and final acute stress affects survival rate, growth, immunity, health physiology, and stress response of oscar (Astronotus ocellatus). Animals 13:1606. https://doi.org/10.3390/ani13101606 PubMed DOI PMC

Zare M, Esmaeili N, Hosseini H, Choupani SMH, Akhavan S, Salini M, Rombenso A & Stejskal V (2024) How do optimum dietary protein and early mild stress events prepare fish for a stressful future? Stress responsiveness of oscar (Astronotus ocellatus) Aquac Rep

Zaretabar A, Ouraji H, Kenari AA, Yeganeh S, Esmaeili N, Amirkolaee AK (2021) One step toward aquaculture sustainability of a carnivorous species: fish meal replacement with barley protein concentrate plus wheat gluten meal in Caspian brown trout (Salmo trutta caspius). Aquac Rep 20:100714. https://doi.org/10.1016/j.aqrep.2021.100714 DOI

Zolfaghari M, Imanpour MR, Najafi E (2011) Effect of photoperiod and feeding frequency on growth and feed sutilisation of fingerlings Persian sturgeon (Acipenser persicus). Aquac Res 42:1594–1599. https://doi.org/10.1111/j.1365-2109.2010.02749.x DOI