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JOURNAL OF THE WORLD AQUACULTURE SOCIETY Vol. 37, No. 4 December, 2006 Dietary Lysine Requirement as Basis to Estimate the Essential Dietary Amino Acid Profile for Jundiá, Rhamdia quelen PAMELA J. MONTES-GIRAO AND DÉBORA M. FRACALOSSI1 Laboratório de Biologia e Cultivo de Peixes de A´gua Doce, Departamento de Aqüicultura, Universidade Federal de Santa Catarina, Rodovia Admar Gonzaga, 1346, 88034-001 Florianópolis, Santa Catarina, Brazil Abstract The present study was designed to determine the optimal dietary lysine requirement for jundiá, Rhamdia quelen, fingerlings. Groups of 17 fish (1.4 6 0.1 g) were stocked in 120-L tanks and were fed semipurified diets (33% crude protein [CP] and 3500 kcal metabolizable energy) containing increasing concentrations of lysine (3.0, 4.0, 4.5, 5.0, 5.5, 6.0, and 6.5% CP). After 119 d, fish weight gain (WG), specific growth rate (SGR), feed intake and feed conversion (FC), apparent net protein utilization (ANPU), body composition (CP, fat, and ash), and vertebral collagen were determined. WG and SGR increased as dietary lysine concentration in protein increased up to 4.5%, reducing at 6.0 and 6.5% lysine. Fish that were fed the lowest lysine concentration presented the worst feed conversion (FC), which improved for fish fed with 4.5% or more lysine. Feed consumption followed the same trend as FC. The highest ANPU was observed in fish fed with 4.5% lysine. Fish fed diets containing 4.5, 5.0, and 5.5% lysine accumulated more body protein (P , 0.05). Collagen vertebral concentration was significantly higher in fish fed with the 4.5% lysine diet. Dietary requirement for lysine was 4.5 or 5.1% depending on the statistical model used for estimation: broken line or polynomial regression, respectively. The requirements for the other essential amino acids were estimated on the basis of the ideal protein concept and were similar to the requirements for other fish species, except for isoleucine, leucine, treonine, and valine, which were higher for jundiá. Jundiá, Rhamdia quelen, is a freshwater catfish native to Latin America, occurring from Argentina to Southern Mexico (Silfvergrip 1996). This species displays fast growth even during the cold months of the Southern Brazil winter (Fracalossi et al. 2004). Also, it shows good resistance to handling, absence of intramuscular bones, and ability to digest dry feed at first feeding (Fracalossi et al. 2002). Such desirable aquaculture features have attracted the attention of Southern Brazil fish farmers. However, very little is known about the nutritional requirements of this species, which could be detrimental to its profitable farming. Knowledge about the dietary essential amino acid requirement of jundiá will optimize dietary protein utilization thereby decreasing ammonia excretion and release in culture effluents. The ideal protein concept, first proposed for terrestrial monogastric animals, assumes the quantitative determination of a reference amino acid requirement, usually the most limiting in 1 Corresponding author. commercial feeds, using the conventional dose–response method. The requirement for the other essential amino acids as determined by this method is estimated based on the fish whole-body amino acid profile, which presents a strong correlation with the dietary requirement (Wilson 2002). Arai (1981) proposed the essential amino acid rate (A/E) calculation in fish nutrition, which is defined as the ratio between the amount of each body amino acid (A) and the sum of the essential body amino acids, including cystine and tyrosine (E). This author observed best growth and feed efficiency for salmon fingerlings that were fed diets formulated to have an amino acid profile similar to that of salmon body composition (Arai 1981). Later, Wilson and Poe (1985) used this method for estimating the amino acid requirements of channel catfish, Ictalurus punctatus. They demonstrated, for the first time in fish, the existence of a strong correlation (r 5 0.96) between body amino acid composition and dietary amino acid requirement, determined based on a dose– response feeding trial. Currently, most studies Copyright by the World Aquaculture Society 2006 388 DIETARY LYSINE REQUIREMENT FOR RHAMDIA QUELEN designed to estimate amino acid requirements in fish adopt this methodology because of time saving and cost effectiveness. Species that have already had their amino acid requirement estimated by the ideal protein concept are the red drum, Sciaenops ocelllatus (Moon and Gatlin 1991), striped bass, Morone saxatilis (Brown 1995), Japanese flounder, Paralichthys olivaceus (Forster and Ogata 1998), black bass, Micropterus salmoides (Portz and Cyrino 2003), and hybrid striped bass, M. saxatilis 3 M. chrysops (Twibell et al. 2003). In general, lysine is the first limiting amino acid in most grain by-products used to manufacture commercial feed. In addition to the importance of lysine as an essential amino acid, it also affects collagen synthesis. Hydroxylysine and hydroxyproline, products of lysine and proline hydroxylation, respectively, are the main constituents of collagen (Sandell and Daniel 1988). According to Baker and Han (1994), lysine should be used as the reference amino acid for estimating other amino acid requirements because lysine is the only one that does not present endogenous synthesis and, unlike the sulfur amino acids, is exclusively required for body protein deposition. Meyer and Fracalossi (2005) determined the muscle amino acid composition of jundiá from the wild and from a farm and estimated the dietary amino acid requirement of jundiá. This study estimated the lysine requirement to be 5.8% protein. However, this estimate was made only by comparing the dietary requirement of some omnivorous fish with the muscle amino acid composition of jundiá. Until now, that estimate is the only information available on the amino acid requirements for jundiá. Therefore, in the present study we aimed to determine the dietary requirement of lysine for jundiá and to estimate the other essential amino acid requirements using the ideal protein concept. Materials and Methods Twenty-one groups of 17 jundiá fingerlings (initial weight and length of 1.5 6 0.1 g and 5.3 6 0.2 cm, respectively) were stocked in 21 tanks, connected to a closed water recirculation 389 system equipped with constant aeration and mechanical and biological filtration. The water flow was approximately 1.5 L/min/tank, and the photoperiod was held constant at 14 h. Fish were acclimated to the experimental conditions for 7 d, during which they were fed a 34% crude protein (CP) and 3500 kcal/kg estimated metabolizable energy (EM) (Meyer and Fracalossi 2004) with 3% lysine protein in a semipurified basal diet. After acclimatization, fish were fed the experimental diets to apparent satiation twice a day (0800 and 1700 h) for 119 d. On each feeding period, diets were offered twice to all tanks to ensure satiation feeding. Feed consumption was recorded daily for each tank. Every 15 d, fish were group weighed, and at the end of the experimental period, five fish from each tank were euthanized by an overdose (200 mg/L) of the anesthetic MS-222 and frozen ( 20 C) for later determination of body composition. Fish handling procedures complied with the Committee for the Ethical Handling of Animals, Universidade Federal de Santa Catarina. Water temperature and dissolved oxygen concentration were measured daily at each feeding session, and total ammonia, nitrite, and pH concentrations were measured every 3 d. Average water temperature, dissolved oxygen, and pH were 30.5 6 0.5 C (6SD), 6.22 6 0.45 mg/L, and 7.0 6 0.1, respectively, while total ammonia and nitrite did not exceed 0.25 mg/L. All water quality parameters were adequate for jundiá growth (Baldisserotto and Radünz-Neto 2004). Experimental Diets Seven isoproteic (34% CP) and isoenergetic (3500 kcal EM) casein- and gelatin-based semipurified diets were formulated varying their lysine concentration (3.0, 4.0, 4.5, 5.0, 5.5, 6.0, and 6.5% protein), according to Table 1. Casein and gelatin contributed to the minimum dietary lysine concentration (3.0% protein), while the other tested concentrations were obtained by the inclusion of synthetic-lysinesubstituting cellulose. An amino acid premix was also added, formulated based on the albumin amino acid profile, which is considered 390 MONTES-GIRAO AND FRACALOSSI adequate for fish (Santiago and Lovell 1998; Wilson 2002). Diets were formulated to meet the amino acid requirements for channel catfish (NRC 1993) and were prepared by mixing the dry ingredients in a ‘‘Y’’ mixer, then adding oils and water (40%). The pH of all diets was adjusted to 7 by using a 6 N NaOH solution (Nose et al. 1974) to avoid possible differences in feed consumption caused by variation on diet palatability. This mixture was pelletized (die diameter 3 mm) and dried in an oven (60 C) for 6 h and stored ( 20 C) until feeding. Diet and Body Composition Analyses The composition of experimental diets is presented in Table 1. All analyses followed the methodology described by the Association of Official Analytical Chemists (AOAC 1999). Briefly, moisture was obtained by drying samples at 105 C until constant weight; ash, by incineration at 550 C for 5 h; fat, by ether extraction (after acid hydrolysis); fiber, by acid detergent digestion; and CP, by Kjeldahl method (N 3 6.25). Dietary amino acids were determined after acid and basic digestion by high-performance liquid chromatography, using ionic change detection (Portz and Cyrino 2003). Acid digestion (6 N HCl for 24 h) was performed in sealed glass tubes under nitrogen (110 C). Cystine and methionine were determined by acid hydrolysis after oxidation with performic acid (Moore 1963). After hydrolysis, solutions were vacuum filtered, diluted to 0.25 M with 0.02 N HCl for adjustment to pH 8.5, and filtered in Millipore membrane (0.45 mm). Tryptophan was analyzed after sample alkaline hydroxylation with lithium hydroxide. TABLE 1. Composition of experimental diets (dry matter basis). Ingredients Amount (%) Casein Gelatin Dextrin Cellulose Cod liver oil Canola oil Carboxymethylcellulose Vitamin and micromineral premixa Macromineral premixb Amino acid premixc L-lysined 13.12 2.78 37.14 11.37 3.38 3.38 2.00 3.00 5.73 18.10 Variable Concentrations of lysine (% protein) Proximate composition (%) 3.0 4.0 4.5 5.0 5.5 6.0 6.5 Dry matter Crude protein Crude fat Fiber Ash Analyzed lysine 87.90 33.35 4.65 8.13 6.76 2.93 92.57 32.80 5.33 7.71 7.20 3.85 90.95 32.94 5.40 8.05 8.03 4.48 91.57 32.95 4.37 7.86 8.17 4.38 92.53 33.07 5.43 7.67 7.76 5.44 91.93 32.89 5.39 8.47 7.82 5.85 90.65 33.06 5.11 8.68 7.70 6.33 a Composition (kg of premix): folic acid 250 mg, pantothenic acid 5000 mg, biotin 125 mg, cobalt 25 mg, copper 2000 mg, choline 25,000 mg, iron 13,820 mg, iodine 100 mg, manganese 3750 mg, niacin 5000 mg, selenium 75 mg, vitamin A 1,000,000 IU, vitamin B1 1250 mg, vitamin B2 2500 mg, vitamin B6 1875 mg, vitamin B12 3750 mg, vitamin C 42,000 mg, vitamin D3 500,000 IU, vitamin E 20,000 IU, vitamin K3 500 mg, and zinc 17,500 mg. b Composition (%): 45.4 dicalcium phosphate, 29.7 potassium phosphate, 17.4 sodium chloride, and 7.5 magnesium sulfate. c Ajinomoto Interamericana Indústria e Comércio Ltd (Sao Paulo, Sao Paulo, Brazil). Composition based on albumin amino acid profile (%): lysine 0, arginine 6.46, histidine 2.55, treonine 5.18, valine 6.57, leucine 9.21, isoleucine 5.88, methionine 3.36, cystine 2.50, phenilalanine 5.73, tyrosine 4.40, tryptophan 1.31, aspartic acid 10.83, glutamic acid 14.09, serine 7.20, alanine 6.00, glycine 3.63, and proline 5.11. d Ajinomoto Interamericana Indústria e Comércio Ltd (Sao Paulo, Sao Paulo, Brazil). Amino acid inclusion (% crude protein): 0.0, 1.0, 1.5, 2.0, 2.5, 3.0, and 3.5, replacing cellulose. 391 DIETARY LYSINE REQUIREMENT FOR RHAMDIA QUELEN At the end of the experimental period, wholebody samples from five fish from each experimental unit were pooled, minced, and homogenized to determine final body composition. The same procedure was adopted for 20 fish (average initial weight 4.2 6 0.9 g) to estimate initial body composition. Body amino acid profile was analyzed in a pooled sample from 17 jundiá (16.6 6 4.8 g body weight) obtained from a commercial fish farmer, following the same methodology adopted for dietary amino acid composition analyses. The vertebral column collagen composition was measured in two samples of one or two fish per dietary treatment at the end of the experimental period, following the methodology described by Mustin and Lovell (1992). A modification was introduced to facilitate vertebral column removal, which consisted of boiling fish for 10 min before vertebrae removal, following a suggestion proposed by Fracalossi et al. (1998). Performance Parameters Performance parameters were calculated using feed consumption data (g/fish) and body and diet composition analyses and were as follows: weight gain (WG) 5 weightfinal weightinitial; feed conversion (FC) 5 feed intake corrected to 10% moisture/WG; daily feed intake (%) 5 feed intake/([fish weightfinal + fish weightinitial]/2)/d 3 100; specific growth rate (SGR) 5 100 3 (lnfish weightfinal lnfish weightinitial)/d; and apparent net protein utiliza- tion (ANPU) 5 100 3 (final body protein initial body protein)/protein consumption. The results of WG, SGR, FC, DFI, ANPU, body composition, and vertebral collagen were submitted to ANOVA, and differences among treatment means were determined by Tukey’s test at 5% significance level. The lysine requirement was estimated based on WG and ANPU data using two statistical methods: polynomial regression (Shearer 2000) and broken line (Portz et al. 2000; Shiau 2001). Results Fish Performance and Estimation of Dietary Lysine Requirement Fingerlings performance data are summarized in Table 2. There was an increase of WG when dietary lysine concentration increased from 3.0 to 4.5%. However, increasing dietary lysine concentration above 4.5% did not improve WG and a decrease was observed at lysine concentrations of 6.0 and 6.5%. Fish fed with the basal diet presented the worst FC, which improved with dietary inclusion of lysine up to 4.5% protein. Feed intake followed the same tendency as FC. After 53 d on the experimental diets, clinical signs of lysine deficiency (lordosis and scoliosis) were evident in some fish feeding diets containing 3.0 and 4.0% lysine. At the end of the experimental period (119 d), three fish (17.65%) fed with 3% dietary lysine and two fish (11.76%) fed with 4% lysine presented scoliosis, lordosis, or both. TABLE 2. Jundiá fingerling performance when fed diets containing different lysine concentrations for 119 d. Diets (% lysine protein) Weight gaina (g) Specific growth rate (%) Feed conversion Daily feed intake (% body weight) Apparent net protein utilization (%) 3.0 (basal) 4.0 4.5 5.0 5.5 6.0 6.5 ANOVA (P value) SEM 5.83y 8.00xy 9.88x 8.21xy 9.89x 7.60xy 7.86xy 0.020 0.53 1.48y 1.70xy 1.92x 1.76xy 1.92x 1.70xy 1.73xy 0.015 0.06 6.39x 3.98xy 2.96y 3.74y 3.35y 3.87y 3.84y 0.004 0.42 8.09x 5.40xy 4.26y 5.19y 4.85y 5.30y 5.22y 0.004 0.46 19.98y 36.43xy 50.30x 45.81xy 49.55x 46.43xy 40.95xy 0.013 4.00 Means (n 5 3) in each column followed by different letters are significantly different (P , 0.05). a Average initial weight is 1.5 6 0.1 g (6SD). 392 MONTES-GIRAO AND FRACALOSSI Based on WG and ANPU data, jundiá dietary lysine requirement was estimated to be 4.5% by the broken line method and 5.1% by polynomial regression (Fig. 1). were observed on fish feeding the lower concentrations of dietary lysine (3.0 and 4.0%) and the highest on fish feeding 4.5% lysine. Body Composition and Vertebral Collagen Calculation of A/E and Estimative of Essential Amino Acid Requirements The effect of increasing levels of dietary lysine on jundiá body composition is summarized in Table 3. Fish consuming diets containing 4.5% protein lysine had more body protein deposition. Body fat was greatest on fingerlings feeding the diets containing the lowest (3.0 and 4.0%) or highest (6.0 and 6.5%) lysine concentrations. The lowest concentrations of collagen The whole-body essential amino acid profile of jundiá was used to calculate the A/E, which is defined as the content of each essential amino acid divided by the sum of all essential amino acids, including cystine and tyrosine, multiplied by 1000 (Arai 1981). The estimated requirement for each of the other essential amino acids, besides lysine, was calculated by the following FIGURE 1. Estimative of lysine dietary requirement for jundiá fingerlings considering weight gain (WG) and apparent net protein utilization (ANPU). Estimative was calculated using the broken line and polynomial regression mathematical models. 393 DIETARY LYSINE REQUIREMENT FOR RHAMDIA QUELEN formula: amino acid requirement 5 lysine requirement 3 (A/E/100) (Fagbenro 2000). The estimated values are presented in Table 4, along with the requirements of other cultivated fish species. Discussion The inclusion of optimal concentrations of essential amino acids is an indispensable requirement to obtain a well-balanced and cost-effective diet. Our findings indicated that 4.5% lysine is the requirement for maximum WG and ANPU by jundiá fingerlings, when the broken line analysis was used to estimate the requirement. However, despite being widely used in numerous requirement studies, this method can underestimate the real nutrient dietary requirement (Shearer 2000; Encarnacxão et al. 2004). When polynomial regression was used, the estimated lysine requirement increased to 5.1% lysine. WG and ANPU decreased in the lower (3.0 and 4.0% protein) and upper (6.0 and 6.5% protein) dietary lysine concentrations, which could indicate an antagonism between arginine and lysine absorption, as suggested by Lovell (1998). The discrepancy between formulated and analyzed lysine values (5 and 4.38%, Table 1) can only be explained by a mistake while preparing that diet because repeated analyses provided similar lysine values. This discrepancy, however, could explain the decrease in WG and ANPU in fingerlings fed with this diet when compared to fingerlings fed with diets containing 4.5% lysine (Fig. 1). If the real analyzed concentration had been equal to the formulated, that is 5%, the estimated requirement could be higher than 4.5%, when using the broken line analysis. The dietary lysine requirement of 4.5% found for jundiá is similar to the value estimated by the broken line method for the carnivorous Asian sea bass, Lates calcarifer (Murillo-Gurrea et al. 1999), and rainbow trout, Oncorhynchus mykiss (Encarnacxão et al. 2004). Nevertheless, the requirement increased to 5.7% when calculated by the polynomial regression method, in the last study, as pointed out by the authors. Generally, studies with carnivorous species that used WG as the parameter to calculate the requirement by the broken line method found a dietary lysine requirement very close to the value determined for jundiá in the present study (Akiyama et al. 1985; Tibaldi and Lanari 1991; Forster and Ogata 1998; Small and Soares 2000). Recent ingredient digestibility studies carried out in our laboratory showed that jundiá utilizes protein sources better than other omnivorous species like Nile tilapia or pacu, Piaractus mesopotamicus (Oliveira-Filho and Fracalossi, 2006). This could indicate that jundiá is an omnivore with carnivorous tendencies. Indeed, the jundiá digestive tract is simple, without pyloric ceca or gizzard, with short and wellspaced gill rakes and short intestine, similar to a carnivorous fish. The best ANPU was shown by jundiá fed with the 4.5% lysine diet (Table 3). Considering lysine as the only amino acid simply used for body protein deposition (Baker and Han TABLE 3. Jundiá fingerling body composition (wet matter basis) after 119 d of feeding different lysine concentrations. Diets (% lysine protein) 3.0 (basal) 4.0 4.5 5.0 5.5 6.0 6.5 Initial composition ANOVA (P value) SEM Dry matter (%) Crude protein (%) Crude fat (%) Ash (%) Collagen (%) 24.46 24.17 24.49 23.85 23.36 23.90 23.31 24.10 ns 0.16 12.04y 12.60y 13.64x 13.41x 13.57x 13.38x 13.29x 13.40 ,0.001 0.22 5.61 5.54 5.17 5.10 5.11 5.52 5.67 5.82 ns 0.01 13.52 11.65 11.83 12.85 12.78 11.95 11.97 10.69 ns 0.26 11.29z 11.66z 24.86x 21.97y 21.89y 21.50y 21.27y — ,0.001 2.04 Means (n 5 3) in each column followed by different letters are significantly different (P , 0.05). 394 MONTES-GIRAO AND FRACALOSSI TABLE 4. Whole-body amino acid profile, amino acid essential rate, estimative of dietary amino acid requirement of jundiá, and amino acid requirement for Nile tilapia, Oreochromis niloticus, channel catfish, Ictalurus punctatus, and rainbow trout, Oncorhynchus mykiss. Estimated requirements Amino acids Whole-body amino acid profilea A/Eb BL Arginine Histidine Isoleucine Leucine Lysine Met + Cys Phe + Tyr Threonine Tryptophan Valine 4.9 1.8 4.9 8.2 7.8 3.9 5.6 4.5 0.9 4.8 103.6 38.0 103.6 173.3 100.0 82.4 118.3 95.1 19.0 101.4 4.7 1.7 4.7 7.8 4.5g 3.7 5.3 4.3 0.9 4.6 Nile tilapiad Channel catfishe Rainbow troutf PR BL BL BL 5.5 2.0 5.5 9.2 5.1g 4.3 6.2 5.0 1.0 5.3 4.2 1.7 3.1 3.4 5.1 3.2 5.5 3.8 1.0 2.8 4.3 1.5 2.6 3.5 5.1 2.3 5.0 2.2 0.5 3.0 3.5 1.6 2.4 4.4 5.3 2.7 5.2 3.4 0.5 3.1 Jundiác Seventeen fish (average initial weight 16.6 6 4.8 g) from a fish farm. A/E (amino acid essential rate) 5 (amount of each amino acid in whole-body/total essential amino acids, including cystine and tyrosine) 3 1000. c Estimated essential amino acid requirements, except for lysine. BL 5 lysine requirement estimated by broken line; PR 5 lysine requirement estimated by polynomial regression. Essential amino acid requirement 5 lysine requirement 3 ([A/E]/100) (Fagbenro 2000). d Santiago and Lovell (1988). e Wilson and Poe (1985). f Ogino (1980). g Data estimated by dose–response feeding trial. a b 1994), the highest ANPU found in fingerlings fed with the 4.5% lysine diet could be an explanation for the higher body protein content found in fish fed with this dietary concentration (Table 4). Similarly, studies performed with channel catfish demonstrated that when a lysine-deficient diet was supplemented with this amino acid, there was an increase in body protein and a decrease in body fat (Robinson 1991; Munsiri and Lovell 1993; Zarate and Lovell 1997). Therefore, it is speculated that the protein synthesis in jundiá increased as dietary lysine concentration increased up to 4.5%. However, Bai and Gatlin (1994) reported that diets with different concentrations of lysine did not affect body composition of channel catfish. An estimate of the other essential amino acid requirements for jundiá based on the body amino acid profile and lysine dose–response requirement is presented in Table 4, which also contains the amino acid requirements of other cultivated species. The requirements for jundiá were comparable to those presented by other species, except for isoleucine, leucine, treonine, and valine, which were higher as a result of its higher concentration in jundiá body protein. The WG and SGR observed in the present study were lower than those presented by jundiá fingerlings fed with semipurified diets containing the same protein and energy concentrations (Meyer and Fracalossi 2004). Such differences could be explained by the addition of single amino acids in the present study, which could have decreased amino acid digestibility and consequently protein synthesis (Lovell 1998). Indeed, daily feed consumption in our study was higher than that reported by Meyer and Fracalossi (2004), probably to compensate for the lower single amino acid digestibility. Additionally, the highest feed consumption was observed in the lowest lysine concentration diets (3.0 and 4.0%), although some studies indicate that essential amino acid deficient diets can decrease feed consumption (Ketola 1982; Yamamoto et al. 2001). Vertebral collagen concentration presented the same tendency as ANPU and WG. Higher DIETARY LYSINE REQUIREMENT FOR RHAMDIA QUELEN vertebral collagen formation was observed in fish fed with the 4.5% lysine diet, confirming the need for lysine as a precursor to hydroxylysine for connective tissue and bone matrix formation (Sandell and Daniel 1988). Fish fed with the basal diet (3% lysine) and the 4% lysine diet presented the lower concentrations of vertebral collagen (P , 0.05) and were the only ones to present clinical signs (scoliosis and lordosis) of poor bone formation. On the other hand, fish fed with the 4.5% lysine diet presented the highest collagen content, suggesting that this dietary concentration is also ideal for collagen formation in jundiá. Conclusions The lysine requirement for jundiá fingerlings is between 4.5 and 5.1% dietary protein, depending on the statistical method applied to estimate the requirement: broken line or polynomial regression, respectively. Other essential amino acid requirements were estimated based on the lysine requirement and the essential amino acid rate obtained by analyzing the jundiá wholebody amino acid profile. The amino acid requirements for jundiá were similar to those for other cultivated fish species, except for isoleucine, leucine, treonine, and valine, which were higher as a result of its higher concentration in the jundiá body. Acknowledgments The authors wish to thank Ajinomoto Interamericana Indústria e Comércio Ltd. (São Paulo, São Paulo, Brazil) for providing the amino acids to formulate the experimental diets. This study was funded by a grant (474338/04-5) from CNPq – Conselho Nacional de Desenvolvimento Cientı́fico e Tecnológico (Brası́lia, DF, Brazil). A Master’s scholarship was also granted to the first author by CAPES – Coordenacxão de Aperfeic xoamento de Pessoal de Nı́vel Superior, Brası́lia, DF, Brazil. Literature Cited Akiyama, T., S. Arai, T. Marai, and T. Nose. 1985. Threonine, histidine and lysine requirements of chum salmon fry. Bulletin of the Japanese Society of Scientific Fisheries 51:635–639. 395 AOAC (Association of Official Analytical Chemists). 1999. Official methods of analysis. Association of Official Analytical Chemists, Inc., Arlington, Virginia, USA. Arai, S. A. 1981. A purified test diet for coho salmon, Oncorhynchus kituch, fry. Nippon Suisan Gakkaishi 47:547–550. Bai, S. C. and D. M. Gatlin III. 1994. Effects of L-lysine supplementation of diets with different protein levels and sources on channel catfish, Ictalurus punctatus. Aquaculture and Fisheries Management 25:465–474. Baker, D. H. and Y. Han. 1994. Ideal amino acid profile for chicks during the first three weeks post hatching. Journal of Poultry Science 73:1441–1447. Baldisserotto, B. and J. Radünz-Neto. 2004. NonEnCriaxcão de jundiá. Universidade Federal de Santa Maria Press, Santa Maria, Rio Grande do Sul, Brazil. Brown, M. L. 1995. Using whole-body amino acid patterns and quantitative requirements to rapidly develop diets for new species such as striped bass, Morone saxatilis. Journal of Applied Ichthyology 11:342–346. Encarnac xão, P., C. de Lange, M. Rodehutscord, D. Hoehler, W. Bureau, and D. P. Bureau. 2004. Diet digestible energy content affects lysine utilization, but not dietary lysine requirements of rainbow trout, Oncorhynchus mykiss, for maximum growth. Aquaculture 235:569–586. Fagbenro, O. A. 2000. Validation of the essential amino acid requirements of Nile tilapia, Oreochromis niloticus (Linnaeus 1758), assessed by the ideal protein concept. Pages 154–156 in K. Fitzsimons, editor. Proceedings of the Fifth International Symposium on Tilapia Aquaculture. Rio de Janeiro, Rio de Janeiro, Brazil, September 2—7, 2000. SRG, Rio de Janeiro, Rio de Janeiro, Brazil. Forster, I. and H. Ogata. 1998. Lysine requirement of juvenile Japanese flounder Paralichthys olivaceus and juvenile red sea bream Pagrus major. Aquaculture 161:131–142. Fracalossi, D. M., M. E. Allen, D. K. Nichols, and O. T. Oftedal. 1998. Oscars, Astronotus ocellatus, have a dietary requirement for vitamin C. The Journal of Nutrition 128:1745–1751. Fracalossi, D. M., E. Zaniboni-Filho, and S. Meurer. 2002. NonEnNo rastro das espécies nativas. Panorama da Aqüicultura 12:43–49. Fracalossi, D. M., G. Meyer, M. Weingartner, F. Santamaria, and E. Zaniboni-Filho. 2004. Desempenho do jundiá, Rhamdia quelen, e dourado, Salminus brasiliensis, em viveiros de terra na região Sul do Brasil. Acta Scientarium 26:345–352. Ketola, H. G. 1982. Amino acid nutrition of fishes: requirements and supplementation of diets. Comparative Biochemistry and Physiology 73B:17–24. Lovell, R. T. 1998. Nutrition and feeding of fish. Kluwer Academic Press, Boston, Massachusetts, USA. Meyer, G. and D. M. Fracalossi. 2004. Protein requirement of jundiá fingerlings, Rhamdia quelen, at two 396 MONTES-GIRAO AND FRACALOSSI dietary energy concentrations. Aquaculture 240: 331–343. Meyer, G. and D. M. Fracalossi. 2005. Muscle tissue amino acid composition of jundiá, Rhamdia quelen, and estimation of its essential amino acid requirements. Scientia Agricola 62:401–405. Moon, H. Y. and D. M. Gatlin III. 1991. Total sulfur amino acid requirement of juvenile red drum, Sciaenops ocellatus. Aquaculture 95:97–106. Moore, S. 1963. On the determination of cystine and cysteic acid. Journal of Biological Chemistry 238:235–237s. Munsiri, I. P. and R. T. Lovell. 1993. Comparison of satiate and restricted feeding of channel catfish with diets of varying protein quantity in production ponds. Journal of the World Aquaculture Society 24:459–465. Murillo-Gurrea, D. P., R. M. Coloso, I. G. Borlongan, and A. E. Serrano. 1999. Lysine and arginine requirements of juvenile Asian sea bass, Lates calcarifer. Journal of Applied Ichthyology 17:49–53. Mustin, W. G. and R. T. Lovell. 1992. Na-L-ascorbyl-2monophosohate as a source of vitamin C for channel catfish. Aquaculture 105:95–100. Nose, T., S. Arai, D. L. Lee, and Y. Hashimoto. 1974. A note on amino acids essential for growth of young carp. Bulletin of the Japanese Society of Scientific Fisheries 40:903–908. NRC (National Reseach Council). 1993. Nutrient requirements of fish. National Academic Press, Washington, DC, USA. Ogino, C. 1980. Requirements of carp and rainbow trout for essential amino acids. Nippon Suisan Gakkaishi 46:171–174. Oliveira-Filho, P. R. C. and D. M. Fracalossi. 2006. Apparent coefficient digestibility of ingredients for juvenile jundiá, Rhamdia quelen. Brazilian Journal of Animal Science 35(4):1581–1587. Portz, L. and J. E. P. Cyrino. 2003. Comparison of the amino acid contents of roe, whole body and muscle tissue and their A/E ratios for largemouth bass Micropterus salmoides (Lacepéde, 1802). Aquaculture Research 34:585–592. Portz, L., C. T. S. Dias, and J. E. P. Cyrino. 2000. NonEnRegressão segmentada como modelo na determinac xão de exigências nutricionais de peixes. Scientia Agricola 57:601–606. Robinson, E. H. 1991. Improvement of cottonseed meal protein with supplemental lysine in feeds for channel catfish. Journal of Applied Aquaculture 1:1–14. Sandell, L. J. and J. C. Daniel. 1988. Effect of ascorbic acid on RNA levels in short term chondrocyte cultures. Connective Tissue Research 17:11–22. Santiago, C. B. and R. T. Lovell. 1988. Amino acid requirement for growth of Nile tilapia. The Journal of Nutrition 188:1540–1546. Shearer, K. D. 2000. Design, analysis and modeling of nutrient requirement studies in fish: a critical review. Aquaculture Nutrition 6:91–102. Shiau, S. Y. 2001. Estimation of nutrient requirement in aquatic animals. Journal of Fishery Sciences of China 28:69–76. Silfvergrip, A. M. C. 1996. A systematic revision of the neotropical catfish genus Rhamdia (Teleostei, Pimelodidae). Ph.D. Dissertation, Department of Vertebrate Zoology, Swedish Museum Natural History, Stockholm, Sweden. Small, B. C. and J. H. Soares. 2000. Quantitative dietary lysine requirement of juvenile striped bass Morone saxatilis. Aquaculture Nutrition 6:207–212. Tibaldi, E. and D. Lanari. 1991. Optimal dietary lysine levels for growth and protein utilization of fingerling sea bass, Dicentrarchus labrax, fed semipurified diets. Aquaculture 95:297–304. Twibell, R. G., M. E. Griffin, J. Martin, J. Price, and P. B. Brown. 2003. Predicting dietary essential amino acid requirements for hybrid striped bass. Aquaculture Nutrition 9:373–381. Wilson, R. P. 2002. Amino acids and proteins. Pages 144– 175 in J. E. Halver, editor. Fish nutrition. Academic Press, New York, New York, USA. Wilson, R. P. and W. E. Poe. 1985. Relationship of whole body and egg essential amino acid patterns to amino acid requirement patterns in channel catfish, Ictalurus punctatus. Comparative Biochemistry and Physiology 80B(2):385–388. Yamamoto, T., T. Shima, H. Furuita, N. Suzuki, F. J. Sanchez-Vazquez, and M. Tabata. 2001. Selfselection and feed consumption of diets with a complete amino acid composition and a composition deficient in either methionine or lysine by rainbow trout, Oncorhynchus mykiss. Aquaculture Research 32:83–91. Zarate, D. D. and R. T. Lovell. 1997. Free lysine (L-lysine) is utilized for growth less efficiently than protein-bound lysine (soybean meal) in practical diets by young channel catfish, Ictalurus punctatus. Aquaculture 159:87–100.