751

VITAMIN A IN DIETS FOR NILE TILAPIA

Daniela Ferraz Bacconi Campeche'*; Rodrigo Ramos Catharino"; Helena Teixeira Godoy";José Eurico Possebon Cyrino '

I ,

Embrapa Semi-Arido - BR 428, km 152, CP. 23 - 56300-970 - Petrolina, PE - Brasil.2 UN1CAMPIFEA _Depto. de Ciência de Alimentos, R. Monteiro Lobato, 80, c.p 6121 - 13083-862 - Campinas,SP - Brasil.

JUSPIESALQ - Deplo. de Zootecnia, Setor de Piscicultura. Av. Pádua Dias, II-13418-900 - Piracicaba , SP-

Brasil.*Corresponding author <daniela.campeche@cpalsa.embrapa.br>

ABSTRACT: Dietary vitamin supplementation decrease stress caused by high stocking density, andboosts immunological system of farmed fish. A studied was carried out to determine vitamin Arequirements ofNile tilapia (Oreochromis niloticusv in an ali mal e group (13.8 ± 1.2 g) and a mixed sexpopulation (9.8 ± 2.3 g). Fish stocked in IOO-L plastic aquaria (26.0 ± I.O°C) were fed to near satiety,twice a day, seven days a week, during 75 days with vitamin A-free, semi-purified diets supplementedwith O; 600; 1,200; 1,800; 2,400; 3,000; 3,600; 4,200; 4,800 and 5,400 International Units (lU) of retinylpalmitate (30% vitamin A) per kg of diet in a completely randomized experimental design, factorialarrangement 2Xl0 (n = 4). Deficiency signs ofvitamin A were observed in fish fed O to 1.200 lU vitaminA kg " diet; moderate signs were observed in fish fed diets with 1.800 to 3.600 lU vitamin A kg-I diet;no interactions group*level (p < 0.05) were detected. Dietary levels of vitamin A up to 5.400 lU kg I

influenced final weight and weight gain of fish (p < 0.05), but did not influence feed consumption(p> 0.05). A group effect was observed regarding ali performance variables (p < 0.000 I). Quantificationof hepatic retinol (HPLC) detected vitamin A only in fish fed 5.400 lU retinol kg' of diet, thereforecharacterizing that dietary retinol was used and stored. The quantity of 5.400 lU of retinol kg-I of dietis recommended for adequate nutrition of Nile tilapia.Key words: Oreochrotnis niloticus, retinol, nutrition

VITAMINA A EM DIETAS PARA TILÁPIADO NILO

RESUMO: A suplementação de vitaminas na dieta diminui o estresse e estimula o sistema imunológicocausado por altas densidades de estocagem dos peixes. Este trabalho determinou a exigência emvitamina A para a tilápia do ilo em uma população monosexo masculina (13.8 ± 1.2 g) e em umapopulação original (9.8 ± 2.3 g). Os peixes foram estocados em aquários plásticos de 100 L (26.0 ±1.0°C) e alimentados "ad libitum", duas vezes ao dia, sete dias da semana, durante 75 dias com dietasemi-purificada suplementada com O; 600; 1.200; 1.800; 2.400; 3.000; 3.600; 4.200; 4.800 e 5.400 UI deretinyl palmitato (30% de vitamina A) por kg de dieta, em um delineamento experimental totalmente aoacaso e arranjo fatorial 2X I O (n = 4). Deficiência nutricional severa foi observada em peixes alimentadoscom O a 1.200 UI vitamina A kg-I de dieta; sinais moderados foram encontrados em peixes alimentadoscom 1.800 a 3.600 UI vitamina A kg-I de dieta; interações grupo*nível (p < 0,05) não foram detectadas.O aumento de nível de vitamina A influenciou no peso final e no ganho de peso dos peixes (p < 0,05),mas não influenciou o consumo de ração (p > 0,05). Foi observado efeito de grupo no desempenhodos peixes (p < 0,000 I). Foi detectado o retinol hepático através de HPLC somente no grupo alimentadocom 5.400 UI de retinol kg-I de dieta, caracterizando assim que o mesmo foi utilizado e armazenado. Aquantidade de 5.400 lU de retinol kg-I de dieta é a mínima' recomendada para tilápia do Nilo.Palavras-chave: Oreochroniis niloticus, retinol, nutrição

INTRODUCTION adequate dietary vitamin supplementation can result indiseases outbreaks 01' reduced growth in a confinedfish population (Hepher, 1988; NRC, 1993; De Silva& Anderson, 1995; Harikumar et aI., 1996; Goswami& Dutta, 1991; Taveekijaran, 1994; Thompson et aI.,1995).

Excess dietary fat-soluble vitamins are stored inhepatic lipid deposits (NRC, 1993; Ornsrud et aI.,

Commercial production of tilapia requires the useof high quality, complete feed. Increasing vitaminsupplementation of complete diets decreases stresscaused by high stocking density, and boosts immuno-logical system of fish (Davis et aI., 1998; Halver,1985; Toguyeni et aI., 1997). On the other hand, in-

Sei. Agric. (Piracicaba, Braz.), v.66, n.6, p.751-756, November/Decernber 2009

752 Campeche et aI.

2002); 90% ofthe stored vitamin A is found in the liver(Katuyama & Matsuno, 1988). Therefore, quantifyingvitamin A depots in hepatic tissue elicits establishingmetabolic and nutritional requirements (Hole & Tay-lor, 1996).

Vitamin A requirements were determined for chan-nel catfish (1,000 to 2,000 International Units (lU) kgI of diet), salmonids (2,500 lU kg-I of diet), carp(4,000 to 20.000 Il.I kg " of diet), Japanese flounder(10.000 lU kg-I of diet) and greasy grouperEpinephelus tauvina (3,10 1 lU kg " of diet) (NRC,1993; Hepher, 1998; Hernandez et aI., 2007; Mohamedet aI., 2003). Saleh et aI. (1995) determined that vita-min A requirement ofNile tilapia is 5,000 lU kg' diet.Hu et aI. (2006) determined that vitamin A requirementof hybrid ti lapia o. niloticus x o. aureus ranges on5,850 to 6,970 lU kg-I. This same author also regis-tered that tilapia can utilize p-carotene to fui fi11the di-etary vitamin A requirements. However, Kubitza et aI.(1998) and Kubitza & Cyrino (1999) reported that Bra-zilian commercial feeds for omnivoraus, tropical fishmay contain from 3,000 to 22,000 lU kg I vitamin A.The aim of this study was to verify the use of vita-min A in diets for Nile tilapia, through the determina-tion of hepatic vitamin A storage capacity and doublecheck discrepant, reported dietary vitamin A require-ment of juvenile Nile tilapia fed semi-purified diets,through the evaluation of grawth rate and defieieneysigns.

MATERIALAND METHODS

Fish (19 per aquarium) were kept in 40 1OO-L plas-tie aquaria, supplied by a elosed reeireulation system.Aeration was provided continuously throughout theexperiment. Water pH, dissolved oxygen (00) and tem-perature (26 ± I.O°C) were monitored on a daily ba-siso Fish were fed for II weeks with vitamin A-free,semi-purified diets supplemented with O, 600, 1.200,1.800, 2.400, 3.000, 3.600, 4.200, 4.800 and 5.400lU ofvitamin A kg-I diet (Table I), in a completely ran-domized experimental design, factorial arrangement2Xl0 (n = 4). Retinyl palmitate (Rovimix TO 500Roche"; 30% vitamin A) was used as dietary vitaminA source. The diet was formulated based on albuminand gelatin protein (Table 1). The mixture was extrudedthrough a mineer (ML-4.0 WEG-~tline); pellets werecollected, dried overnight in a forced air oven (55°C);grinded to 1 mm pellets, sized, hermetically packed andstored under refrigeration until use. Fish were fed tonear satiety twice a day (6:00 am and 6:00 pm).

The trial was duplicated with (i) an all-male, sex-reversed Nile tilapia juvenile population (SR), (13.76± 1.21 g), and (ii) a mixed-sex population (NSR) (9.83

Table I - Forrnulation and proximate composition of theexperimental diets.

Ingred ients Contents (0/0)

Albumin

Gelatin

Corn starch

Soybean oil

a - Cellulose

Bica\cium Phosphate

Vitamin A-free and mineral rnix

Vitarnin C2

Sodium chorideBHT)

32.10

7.70

44.13

6.00

6.00

3.00

0.500.05

0.500.02

Proximate composition

Dry rnatter (0/0) 92.09

Gross energy (kcal kg-') 4791

Crude protein (0/0) 34.70

Crude lipid (0/0) 2.65

Crude fiber (0/0) 3.83

Ash (0/0) 4.79

'Units kg -, of diet: vil D) 200,000 UI; vit E 12,000 mg; vil. KJ2,400 mg; vit B, 4,800 mg; vit B2 4,800 mg; vil B6 4,000 mg; vitB'2 4,800 rng; folic acid 1,200 mg; pantothenic acid 1,200 mg; vitC 48,000 mg; biotin 48 mg; niacin 24,000 rng; Fe 10.000 mg; Cu600 mg; Mn 4,000 mg; Zn 6,000 mg; I 20 mg; Co 2 mg; Se 20 mg.2Vit C (Lutavit C- Aquastab BASr®). JBHT= Butil hidroxitolueno.

± 2.30 g). Fish were acclimated to the aquaria and fedfor fifteen days prior to the beginning of the feedingtrials with the non-supplemented diet to simulate or in-duce deficiency (NRC, 1993).

Apparent signs of vitamin A deficieney - e.g.exophthalmia, depigmentation, clouding of corneal epi-thelium, anorexia, warped gill operculum, reducedgrowth, poor feed efficiency, and high mortality(Tacon, 1992) - were recorded through visual obser-vations along the experimental period and at the endof the trial in ali fish. The following growth data wererecorded at the beginning and ending the experimentalperiod: initial and final weigh; weight gain [(finalweigh) - (initial weigh)]; feed consumption; feed con-version ratio [(feed eonsumption) -:-(weight gain)]; andsurvival rate [100 x (final number of animais) -i- (ini-tial number of animais)]. At the end of the trials, he-patic tissue was sampled frorn fish and stored in liq-uid nitrogen. High pressure liquid ehromatography(HPLC) was utilized to quantify vitamin A in the he-patie tissue lipid depots (Landen-Júnior & Eitenmiller,1979).

Data were submitted to ANOVA and regressionanalysis by the PROC GLM, SAS software (SAS In-

Sei. Agrie. (Piracieaba, Braz.), v.66, n.6, p.751-756, NovemberlDeeember 2009

Vitarnin A in diets for Nile Tilapia 753

stitute, 2001), for linear and quadratic effects of thetreatments on final weight (FW), weight gain (WG),feed conversion rate (FCR) and survival (S).

RESULTS AND DISCUSSION

Deficiency signsThe same clinical deficiency signs were observed

for animaIs of ali groups fed vitamin-A deficient diet.Normally colored livers with dark-colored gal bladders,a characteristic sign of clinical stress (Halver, 1989;Roberts, 1981; Post, 1987; Steffens, 1989; Tacon,1992; Plumb, 1999) was also recorded (Table 2).

Vitamin A deficiency signs in o. niloticus include:abnormal swimming behavior; internal hemorrhages;protruded, blind eyes; anemia; hemorrhage in the baseoffins and in the skin (Saleh et a!., 1995). Tn advanceddeficiency condition Saleh et a!. (1991) also observedwidespread depigmentation and edemas in the abdo-men, sometimes associated with ascites; reduction ofmucus secretion and dry, hard mucous tissue. Lesionsobserved post-mortem appeared as ascites, clubbedgills and hemorrhagic kidneys. Hemorrhagic, amor-phous, granulomatous spleen; necrotic, granulomatous,amorphous liver were conspicuously found in thepresent work in fish receiving less than 1,200 TU vi-tamin A kg' diet. Spleen severe conditions were alsoregistered to a lesser extent in fish fed diets contain-ing 1,800~2,400 lU vitamin A kg " diet.

Cherry salmon Oncorhynchus massou fed vitaminA-deficient diets for 15 weeks presented c1inical signssimilar to those described above (Taveekijaran et a!.,1994). Similar observations were reported for catfishHeteropneustes fossilis, greasy grouper Epinephe!ustauvina, Atlantic halibut Hippoglossus hippoglossus L.and sunshine bass juvenile Morone chrysops x M.saxatilis (Harikumar et a!., 1996, Mohamed et a!.,2003; Moren et a!., 2004; Hemre et a!., 2004). Theuse of advanced juveniles, which may have adequatebody reserves of vitamin A, may explain the low inci-dence of ocular problems, opposing to observationsof Poston et a!. (1977) with rainbow trout.

Growth parametersWeight gain (WG), feed conversion ratio (FCR),

survival (S) and feed consumption rate (FCR) data arepresented in Table 3. A linear effect (p < = 0.01) wasdetected for FW and FCR, but no effect was detectedregarding WG (p > = 0.05) (Figure 1 and 2). This mayhave resulted from differences in fish initial weight.Several research reports are in accord to these results.Hu et a!. (2006) reported that hybrid tilapia fed dietssupplemented with 50,000 IU vitamin A kg-I presentbetter weight gain (601 %) and better feed conversionratio (1.00). Saleh et a!. (1995) also observed that Niletilapia juveniles fed diets supplemented with 5,000 lUvitamin A kg-I presented better weight gain (23.9 g),better feed consumption rate (60.2 g), and better feed

Table 2 - Percent incidence of clinical signs ofvitamin A deficiency recorded in alI Nile tilapiajuveniles fed diets varyingvitamin A levels.

o 1,800 5,400Deficiency signs of vitamin A recorclec1 (%)

Diel600 1,200 2,400 3,600 4,2003,000 4,800--------------------------------------- mg vil A kg: ---------------------------------------

Clinical signs c1uringthe experimentperioc1

Pale liver 0.13

SR NSR SR NSR SR NSR SR NSR SR NSR SR NSR SR NSR SR NSR SR NSR SR NSR

0.130.13

0.13 0.13 0.13Skin without scale

Cataract

Hemorrage lateraltinExophtalrn

0.26 0.13

0.52 0.39

0.13 0.13

0.13

0.13Clínical signs afterlhe experimentperioc1

0.13 0.13Asciies

Granulornatous,necrotic spleenGranularnatous,amorphous liver

Amorphous kiclney

0.65 0.65 2.630.65 2.10 27 1.71 1.44 1.44 0.39 0.65 0.13

3.945.003.943.94 2.10 0.65

2.63 2.633.94 3.94

SR = sex-reverted; NSR = non sex-reverted

0.13 0.13

0.13 0.13 0.13

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754 Campeche et aI.

Table 3 - Growth perforrnance ofthe juveniles fed diets varying vitamin A levels.

Group FCIW FWGrowth performance

WG FCR

SRSR

Vitarnin A levei(lU kg-I)

O

600

1200

1800

2400

3000

3600

4200

4800

5400

------------------------------------------------- g --------------------------------------------------13.76 43.70 29.94 33.82 1.12

9.83 27.03 17.22 25.45 1.49

11.14 31.61 20.46 32.46 1.58

10.64 30.09 19.45 29.62 1.53

11.94 33.29 21.35 28.83 1.38

11.70 32.84 21.14 26.04 1.28

12.93 36.72 23.79 28.16 1.20

12.73 37.24 24.51 29.10 1.20

12.56 38.58 26.02 30.85 1.23

10.97 37.02 26.05 29.90 1.17

11.74 37.49 25.75 29.34 1.16

11.55 38.81 27.26 32.04 1.20

conversion ratio (2.5), than fish fed diets containingO, 10,000 01' 40,000 IU vitarnin A kg". Moharned etaI. (2003) observed that diets supplernented with 3,764mg vitamin A kg' for greasy grouper led to a betterweight gain (420.94%), better feed conversion ratio(1.42) and better protein efficiency ratio (2.08). Sun-shinc bass fed diets supplemented with 509 - 40,516Jlg vit A kg-I had no difference in weight gain (269-285%) or feed efficiency (0.88-0.89) (Hemre et aI.,2004). On the other hand, Hernandez et aI. (2007) ob-served that Japanese flounder Paralicthys olivaceousfed fish meal-based diets supplemented with 0.00 lUvitamin A kg' presented better specific growth rate(4.9%). Also, Atlantic halibut fed diets supplementedwith 0-250 mg of retinal kg-I had no differences infinal weight 01' mortality (Moren et aI., 2004).

Survival rate obeyed to a quadratic effect (p < =0.001) (Figure 3). Saleh et aI. (1995) reported thatgroups of Nile tilapia receiving 5,000 and 10,000 lUvitamin A kg-1 diet had 93% survival ratio. Thus in-creasing dietary vitamin A levels up to 10,000 lU kg-1

do not significantly reduce survival rate of ile tila-pia. Mortality rate of rainbow trout juveniles was notinfluenced when feeding on either vitarnin A-free dietor diets supplemented with 10,000 lU of retinyl palrni-tate kg-1 for a maximum 20 weeks (Poston et aI.,1977). This data for rainbow trout corroborates re-sults for Japanese flounder, greasy grouper, hybrid ti-lapia, and sunshine bass (Hernandez et aI., 2007;Mohamed et aI., 2003; Hemre et aI., 2004; Hu et aI.,2006).

SR = sex-reversed; NSR = non sex-reversed, IW= initial weight; FW = final weight; WG = weight gain; FC = food consumption; FCR= food conversion rate.

60 SRo• NSR50

Ol::- 40s:Ol'ãi 30:s:ro oc 20ü:: •

10y 0.0013x + 13.811

R2 = 0.65

y = 0.0016x + 25.489

R2 = 0.63o

o

o +---,---,---,--,---,---,---,---,---,o 600 1200 1800 2400 3000 3600 4200 4800 5400

Levei of Vitamin A lU kg-1

Figure I - Final weight (FW) ofthe animais (SR: sex-reverted;NSR: non sex-reversed) in response to the levels ofvitamin A inclusion.

2.5

2 2roo::co 1.5 rtQ)

>co

o: 1o"'ClooLL

oo

• FCSRo FCNSR

o Y = -0.0001 x + 1.9195

R2= 0.82c

• • ~• • • •y = -6E-05x + 1.3087

R2 = 0.37

600 1200 1800 2400 3000 3600 4200 4800 5400

Levei of Vitamin A lU kg-1

Figure 2 - Food conversion rate (CR) ofthe animaIs (FCSR: sex-reverted; FCNSR: non sex-reversed in response to thelevels ofvitamin A inclusion.

Sei. Agrie. (Piracieaba, Braz.), v.66, n.6, p.751-756, NovemberlDeeember 2009

Vitamin A in diets for Nile Tilapia

1201100i

I

-g<802

E

• SR o NSR

y = 0.002x + 84.369R2= 0.3519

• •••• • oo o o o

ro 60>.~

. ::I---~--~---'---~_._~--O

y = 0.0044x + 55.952R2= 0.6528

1000 2000 3000 4000

Levei of Vitamin A lU kg-1

Figure 3 - Survival rate (S) in response to lhe different levels ofvitamin A inclusion (SR: sex-reversed; NSR: nonsex-reverted),

5000 6000

Regardless of dietary vitamin A leveI, sex-reversedfish had better growth rates in comparison to the mixedsex groups. Actually, monosex tilapia populations usu-ally present better growth rates as a result of alteredendocrine status induced by populational skewed sexratio (Toguyeni et aI., 1997).

Hepatic retinolHigh performance liquid chromatography (HPLC)

analyses did not detect vitamin A in hepatic tissuesampled from fish receiving O to 4,800 lU of retinylpalmitate kg-I diet. The detectable leveI was of 45 ±10 mg of vitamin A 100 g-I hepatic tissue. Only fishreceiving the 5,400 lU kg " presented detectableamounts - 136 ± 10 mg of vitamin A 100 g-I hepatictissue. Therefore only this leveI of dietary vitamin Asupplementation exceeded fish metabol ic requirementsand so, only after meeting the metabolic needs of theanimaIs, it could be stored in the liver. Fontagné et a!.(2006) fed Siberian sturgeon Acipenser baeri larvaewith vitamin A and also found retinal palmitate as themain storage form of vitamin A with 6.7 ug g-I in lar-vae fed diets with the highest vitamin A leveI, that was772,500 lU kg' .

Camargo et a!. (1975) determined concentrationsof retinol (mg g-I) and other-cornpounds derived fromvitamin A in hepatic lipid depots of six neotropical,fresh water fish captured in the Moji-Guaçu river, Stateof Sao Paulo, Brazil: curimbatá Prochilodus scrofa 3.32;dourado Salminus maxillosus 7.62; piapara Leporinuspiapara 4.30; mandiuva Pimelodus darias 2.85; piavaLeporinus copelandi 3.40. Hole & Taylor (1996) re-ported that the dogfish Squalus acanthias concentrateas little as 0.047 mg g-I retinol in the liver. Hernandezet a!. (2007) also did not detect retinol in livers of Japa-nese flounder fed fish meal-based diet not supple-mented with vitamin A, and the leveI of retinol in thefishliver increased respectively, in the diets supple-mented with 10,000 lU vitamin A kg-I and 25,000 IU

755

vitamin A kg-I respectively. Hemre et a!. (2004) reportedfor sunshine bass fed diets supplemented with 0-509f1g of retinyl acetate kg I, the leveI detected by HPLCwhere over 924 !lg of retinyl acetate kg Iwas supple-mented in the diet. Vitamin A retention was not sig-nificant in hybrid tilapia fed diets supplemented withlevels below 6,000 IU vitamin A kg-I when detectedby HPLC (Hu et a!., 2006).

ln exception to the dourado, all other fish studiedby Camargo et a!. (1975) had plant material as majorfood items; this same feeding behavior is true for Niletilapia (Lowc-McConnel, 1975; Bcveridge &McAndrcw, 2000). Rodriguez-Amaya (1999) reportedthat the concentration of ~-carotene, a conspicuouspro-vitamin A in plant tissue tops 360 lU g-I; actually,any plant tissue which contains 46~ 74 lU g-I ~-caro-tene is considered a concentrated source of vitaminA. In exception to the control (no supplementation),any other tested leveI within the scope of this work(600~5,400 lU of vitamin A kg-I of the diet) lies withinthe high to the mega-dose of dietary vitamin A supple-mentation. Therefore, the amount of hepatic retinoldetected in this study meets any assumed expectation,and the fact that the highest dietary vitamin A contents- 5,400 lU kg-I - elicited best growth performancedo not surprise either.

ACKNOWLEDGEMENTS

Authors are indebted to Fundação de Amparo àPesquisa do Estado de São Paulo (FAPESP- Sao PauloState Rcsearch Foundation) for the financial supportto this research project in the form of the MSc schol-arship to DFBC.

REFERENCES

BEVERIDGE. M.C.M.; MeANDREW, B.J. Tilapias: biology andexploitation (Fish and Fisheries Series, 25). London: KluwerAeademie, 2000. 505p.

CAMARGO, L.A.A.; YASHUDA, Y.; SAAD, W.A. Vitamina A emóleo de fígado de peixes brasileiros de água doce. ArchivosLatinoamericano de Nutrición, v.25, p 273-281, 1975.

DAVIS, K.B.; SIMCO, W.A.; LI, M.; ROBINSON, E. Effect ofreduetion of s u pp lem e ntar y dietary vitamins on the stressresponse o f ehannel eatfish l ct al urus punct atus. Journal 01"Lhe WorId Aquaeulture Society, v.29, p.319-324, 1998.

DE SILVA, S.S.; ANDERSON, T.A. Fish nutrition in aquaculture.London: Chaprnan & Hall, 1995. 319p.

FONTAGNÉ, S.; BAZIN, D.; BREQUE, 1.; VACHOT, C.;BERNARDE, c., ROUAULT, T.; BERGOT, P. Effeets of dietaryoxidized lipid and vitarnin A on the early developrnent andantíoxídant status of Siberian sturgeon (Acipenser baeri) larvae.Aquaculture, v.257, p.400-411, 2006.

GOSWAMI, U.c.; DUTTA, N.K. Vitamin A-dcfieient diet and itseffcets on ecrtain hacmatological paramctcrs of Heteropneustcsfossilis a 3-4 dehydroretinol rieh frcswater fish. InternationalJournal 01" Vitamin Nutrition Research, v.61, p.205-209,1991.

Sei. Agrie. (Piracieaba, Braz.), v.66, n.6, p.751-756, NovemberlDecember 2009

756 Campeche et a!.

HALVER, J.E., Recent advanccs in vitamin nutrition and metabolismin fish. In: COWEY, C.B.; MACKIE, A.M.; BELL, J.G. Nutritionand feeding in fish. London: Academic Press, 1985. p.415-429.

HALVER, J.E., The vitamins. In: HALVER, J.E. Fish nutrition.2 ed. San Diego. Acadernic Press, 1989. p.32-109.

HARIKUMAR, P.; KARATI, R.; GOSWAMI, U.c. Vitamin A-deficiency and its effects on the Iysosomal enzyrnes of fish.International .luu r n al 01" Vitamin Nutrition Rescarch,v.66, p.97-100, 1996.

HEMRE, GI.; DE G, D.F.; WILSO ,R.P.; BER TSSE ,M.H.G.Vitarnin A metabolism and earlier biological responses in juvenilesunshine bass (Morone chrysops x M. saxatilis) fed gradcd levelsof vitamin A. Aq u acultu re , v.235, p.645-658, 2004.

HEPHER, B., Nut rifion of pond fishes. Cambridge: CambridgeUniversity Press, 1988. 388p.

HERNANDEZ, L.HH.; TECHIMA, S.; KOSHIO, S.; ISHIKAWA,M; TANAKA, Y.; ALAM, M.S. Effects of vitamin A on growth,serum anti-bacterial activity and transaminase activities in thejuvenile Japanese flounder, Paralichtys olivaceus. Aquaculture,v.262, p.444-450, 2007.

HOLE, S.M.; TAYLOR, K.D.A. Mcthods of extraction compositionand stability of vitamin A and other components in dogfishiSqualus acanthiasv liver oil. Food Chemestry, v.55, p.215-220, 1996.

HU, C.J.; CHEN, S.M.; PAN, C.H.; HUANG, C.H. Effccts of dietaryvitamin A or ~-carotene concentrations on growth of juvenilehybrid tilapia, Oreochromis niloticus x o. aureus. Aquaculture,v.253, p.602-607, 2006.

KATUYAMA, M.; MATSUNO, T. Carotenoid and vitamin A, andmetabolism of carotenoids, ~-carotcne, canthaxanthin,astaxanthin, zeaxanthin, lutein and tunaxanthin, lute in andt una x an t h in in tilapia Tilapia nil oti ca . Compara tiveBiochemistry and Physiology. v.90B, p.131-139, 1988.

KUBITZA, F.; CYRINO, J.E.P. The effects of feed quality andfeeding practices on the quality of fish: a Brazilian fish cultureoutlook. In: CHANG, Y.K.; WANG, S.S. (Ed.) Advances inextrusion technology. Lancaster: Tcchno mic, 1999. 171 p.

KUBITZA, F.; CYRINO, J.E.P.; ONO, E.A. Rações comerciaispara peixes no Brasil: situação atual e perspectivas. Panoramada Aqüicultura. v.8, p.38-49, 1998.

LANDEN JÚNIOR., W.O.; EITENMILLER, R.R. Appliccation ofgel permeation chromatography and nonaqucous rcverse phasechromatography to high pressure liquid chromatographicdetermination of retinyl palmitate and ~-carotene in oil andmargarine. Journal of the AOAC International, v.62, p.283-289, 1979.

LOWE-McCONNEL, R.H., Fish communities in tropicalfreshwaters. London: Longman, 1975. 337p.

MOHAMED, J.S.; SIVARAM, V.; ROY, T.S.C.; MARIAM, M.P.;MURUGADASS, S.; HUSSAIN, M.F. Dietary v ita m in Arequirernent of juvenile greasy grouper (Epinephelus tauvina i.Aquaculture, v.219, p.693-701, 2003."

MOREN, M.; OPSTAD, 1.; BERNTSSEN, M.H.G; INFANTE, J.L.Z.;HAMRE,K. An optimum levei of vitamin A supplements forAtlantic halibout (Hippoglossus hippoglossus, L.) juveniles.Aquaculture, v.235, p.587-599, 2004.

NATIONAL RESEARCH COUNCIAL - NRC. Nu t r ie n trequirements of fish. Washington, D.C.: National AcademyPress, 1993. I 14p.

ORNSRUD, R; GRAFF, I.E.; HOIE, S; TOTLAND, G.K.; HEMRE.G..1. Hypervitaminosis A in first-feeding fry of thc Atlanticsalmon (Salmo solar, L.). Aquaculture nutrition. v.8, p.7-13,2002.

PLUMB, J.A. Health maintenance and principal microbialdiseases 01" c u lt ur ed fishes. Ames: lowa State UniversityPress, 1999, 328p.

POST, G. Textbook of fish health. cptune City: T.F.H.Publications, 1987, 288p.

POSTON, H.A.; RIIS, R.C.; RUMSEY, G.L.; KETOLA, H.G. Thecffect o f supplemcntal dictary a m ino acids, minerais andvitamins on salmonids fcd cataractogenic diets. CornellVcterinary, v.67. p.472-509. 1977.

ROBERTS, R.J. Patologia de 105 pcces. Madrid: Mundi-Prcnsa,1981. 355p.

RODRIGUEZ-AMAYA, D.B. Carotenoides y preparación dealimentos: Ia retención de Ias carotenoides provitamina A enalimentos preparados, proccsados y almacenados. Washington,D.C.: USAID/JSI, 1999. 105 p. (OMNI Project).

SALEH, G.; ELERAKU, W.; GROPP, J.M. A short note on theeffects of vitamin A hypervitaminosis on health and growth ofTilapia nilotica (Oreochromis niloticus ). Journal 01"AppliedIchthyology, v.ll, p.382-385, 1995.

SAS INSTITUTE. SAS/STAT user+s guide: statistics v.8.2. Cary:SAS Institutc, 2001

STEFFENS, W. Principies 01" fish nutrition. Ncw York: HasltedPress, 1989. 384p.

TACON, A.G.J. Nutr itinn al I"ish pathology. Rornc: FAO, 1992.75p. (FAO Fisheries Technical Paper, 330)

TAVEEKIJARAN, P.; MIYAZAKI, T.; MATSUMOTO, M.; ARAI,S. Vitamin A dcficiency in cherry salmon. Journal 01"aquaricanimal health, v.6, p.251-259, 1994.

THOMPSON, 1.; CHOUBER, C.; HOULlHAN, D.F.; SECOMBES,C.J. The effcct of dietary vitamin A and astaxanthin on theimmunocompetence of rainbow tro ut. Aquacutt ure, v.133,p.91-102,1995.

TOGUYENI, A.; FAUCONNEAU, B.; BOUJARD, T.: FOSTIER,A.; KUH ,E. R.; MOL, K.A.; BAROILLER. J.F. Feedingbehavior and food utilization in tilapia, Oreochromis niloticus.effect of scx ratio and relationship with the cndocrine status.Physiology Be h avi o u r , v.62, p.273-279, 1997.

Received December 17, 2007Accepted May 28, 2009

Sei. Agrie. (Piraeieaba, Braz.), v.66, n.6, p.751-756, NovemberlDeeember 2009