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UNIVERSIDADE FEDERAL DO RIO GRANDE
PROGRAMA DE PÓS-GRADUAÇÃO EM AQÜICULTURA
Cristina Vaz Avelar de Carvalho
Exigência protéica de juvenis de tainha Mugil platanus
RIO GRANDE, RS
2008
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UNIVERSIDADE FEDERAL DO RIO GRANDE
PROGRAMA DE PÓS-GRADUAÇÃO EM AQÜICULTURA
Cristina Vaz Avelar de Carvalho
Exigência protéica de juvenis de tainha Mugil platanus
Dissertação apresentada como parte dos
requisitos para obtenção do grau de Mestre
em Aqüicultura no Programa de Pós-
Graduação em Aqüicultura da Universidade
Federal do Rio Grande.
Orientador: Prof. Dr. Luís André Sampaio
Co-orientador: Prof. Dr. Marcelo Borges Tesser
Rio Grande – RS
Julho de 2008
ads:
i
Sumário
Dedicatória ..................................................................................................................ii
Agradecimentos ..........................................................................................................iii
Resumo ........................................................................................................................iv
Abstract ........................................................................................................................v
Introdução Geral..........................................................................................................1
Objetivo ........................................................................................................................7
Referências Bibliográficas.............................................................................................8
Artigo anexo ................................................................................................................9
Conclusões ................................................................................................................42
ii
Dedico in memoriam esta dissertação à minha avó Ernestina
iii
AGRADECIMENTOS
Ao meu orientador Prof. Luís André Sampaio, por todas as oportunidades, por seu
incentivo e paciência. Obrigado por ter me orientado na FURG desde a graduação. A
você minha admiração, gratidão e respeito.
Agradeço ao meu co-orientador Prof. Marcelo B. Tesser, pelo auxílio às
atividades e discussão deste experimento.
Agradeço a Prof. Maude e o Prof. Kleber pela colaboração e ensinamentos nestes
anos de convívio.
Ao curso de Pós-Graduação em Aqüicultura e a cada um dos professores deste
curso.
Agradeço a Vivi, Grazi, Adri, Lisa, Carol, Sabrina, Paula, Andrea, Emeline,
Roberta, Lisa, Cintia pelo apoio, incentivo, pela amizade e pelo maravilhoso convívio de
todos estes anos.
Gostaria de agradecer a todos os colegas da EMA, Okamoto, Ricardo, Marlon,
Caue, Eduardo, Roberta, Marcelo, Talibã, Diogo, Ju, Angela pela convivência e amizade.
Gostaria tambem de agradecer a Tati pela ajuda com o fito, agradecer a Lina, a
Pita, ao Getúlio, Zezinho, Sandro pelas conversas e pelo café. Agradeço também ao
Fabiano, Marcos, Nero e Lúcio.
Agradeço a Profa. Marta e a Técnica Maria do Laboratório de Bioquímica
Tecnólogica da FURG e ao André e a Ana Elice do Laboratório de Nutricão Animal da
UFPel pelo auxílio nas análises da ração e dos peixes.
Agradeço a CAPES pelo suporte financeiro.
Aos amigos que fiz durante a graduação e o mestrado.
Agradeço à minha família, meus amados pais, Joanice e João, e aos meus irmãos,
Viviane e Júnior, por todo apoio, carinho e amor.
Agradeço a minha família gaúcha, Helo, Vera e Nelson.
Enfim, a todos que de maneira direta ou indireta me ajudaram não só na
realização dessa dissertação, mas em toda a minha trajetória.
iv
RESUMO
A alimentação é um dos principais custos da piscicultura, sendo importante desenvolver
estudos que busquem uma maior eficiência alimentar para o aumento do sucesso da
atividade e também para a redução do impacto da emissão de nutritientes ao meio
ambiente. Levando em conta o potencial de criação da tainha Mugil platanus na região
Sudeste e Sul do Brasil e a carência de informações sobre suas exigências nutricionais, o
presente trabalho foi realizado com o objetivo de determinar a exigência protéica para
seus juvenis. As tainhas foram alimentadas com cinco dietas com três repetições cada,
sendo cada unidade composta por um tanque de 50L com 50 juvenis com peso inicial
1,17 ± 0,02 g e 4,34 ± 0,03 cm (média ± EP). As cinco dietas isocalóricas foram
formuladas para conter níveis crescentes de proteína bruta (PB) de 30% , 35%, 40%, 45%
e 49% e 18,7 MJ/Kg de dieta (energia metabolizável). As dietas foram oferecidas até a
saciedade 5 vezes ao dia durante 35 dias. As dietas não apresentaram diferenças
significativas (P > 0,05) para sobrevivência, eficiência alimentar e composição corporal.
Os resultados indicaram que o nível de 35% PB foi estatisticamente superior (P > 0,05)
com relação ao ganho em peso, ingestão de alimento e taxa de crescimento específico do
que de tainhas alimentas com o maior nível protéico. A necessidade de proteína para os
juvenis de tainha foi estimada em 35,8% PB.
Palavras chaves: proteína, crescimento, excreção, alimentação, nutrição, peixe
v
ABSTRACT
Feed is one of the main costs for fish culture. Studies looking for higher feed efficiency
are important to increase the success of aquaculture and reduce impacts of nutrient
emission into the environment. Considering the potential of the mullet Mugil platanus for
aquaculture, as well as the lack of information on its nutritional demands, the main goal
of the present work was to determine the dietary protein requirement of juvenile mullets.
Five isocaloric diets were formulated in order to contain increasing levels (30, 35, 40, 45,
and 50%) of crude protein (CP) corresponding to 18.7 MJ metabolizable energy/Kg. All
diets were tested in triplicate. Each experimental unit was composed of a 50 L tank with
50 juveniles (mean ± SE initial weight and length equal to 1.17 ± 0.02 g and 4.34 ± 0.03
cm, respectively). Diets were offered five times a day until apparent satiation for 35 days.
No significant difference (P > 0.05) was observed in survival rate, feed efficiency and
body composition between treatments. However, weight increase, feed ingestion and
specific growth rate was higher in fish fed the 35% CP level than those fed the highest
protein content diet (50% CP). The amount of postprandial ammonia excreted by mullet
was linearly related to protein intake. Intestinal tryptic activity was inversely proportional
to the percentage of dietary CP. The dietary protein requirement of juvenile mullet was
estimated as 34.28% CP with a P:E ratio of 18.7 g/MJ.
Keywords: diet, protein, growth, excretion, feeding, nutrition, fish
1
1. Introdução Geral
Os membros da família Mugilidae, conhecidos popularmente por tainhas, são
peixes costeiros encontrados em ambientes marinhos e estuarinos (Menezes e Figueiredo,
1985).
O cultivo de tainhas é uma realidade em várias regiões do mundo, sendo o Egito,
atualmente, o maior produtor de Mugil cephalus (SOFIA, 2006). A criação de tainha vem
sendo realizada em mono e ou policultivo em vários países como Itália, Israel, Taiwan,
Egito, China, Cuba e Colômbia (Godinho et al., 1988).
No Brasil, os mugilídeos são de grande importância para a pesca artesanal (Reis et
al., 1994). Na região do estuário da Lagoa dos Patos, no Rio Grande do Sul, a pesca de
Mugil platanus é importante economicamente para a comunidade local (Reis e D`Incao,
2000).
Esta espécie ocorre desde o estado do Rio de Janeiro no Brasil, até a Argentina
(Menezes e Figueiredo, 1985). Seus juvenis deslocam-se das regiões costeiras para águas
estuarinas e lagunares, ricas em alimento, onde passam sua fase de crescimento e na
época de desova migram para o mar. No Rio Grande do Sul é frequente a presença de
juvenis ao longo do ano no estuário da Lagoa dos Patos (Vieira e Scalabrin, 1991).
O hábito alimentar de M. platanus se diferencia de acordo com a fase de seu ciclo
de vida, passando de planctófagos a iliófagos (Oliveira e Soares, 1996) e podem atingir
cerca de 1 m de comprimento, com peso em torno de 6 kg (Vieira e Scalabrin, 1991).
O protocolo para reprodução em cativeiro e obtenção de juvenis de M. platanus
ainda não estão bem definidos (Scorvo Filho et al., 1988). Rocha (1981) descreveu os
2
procedimentos básicos que devem ser seguidos para a reprodução e larvicultura de
mugilídeos enquanto que as primeiras tentativas de indução para reprodução da tainha M.
platanus são relatadas por Godinho et al. (1982, 1984).
Além de sua importância econômica para a pesca, a tainha M. platanus apresenta
características que a qualifica como uma alternativa para a piscicultura nas regiões Sul e
Sudeste do Brasil. Está espécie é eurialina e euritérmica (Godinho, 2005), suporta bem
condições de confinamento, aceita com facilidade alimentos artificiais e é possível que
sua produção seja feita em sistemas de mono e policultivo com outras espécies de peixes
e crustáceos (Benetti e Fagundes Netto, 1991; Neto e Spach, 1998/1999; Sampaio et al.,
2001).
Estudos realizados sobre a susceptibilidade de juvenis de M. platanus à fatores
potencialmente limitantes para sua criação foram realizados. Miranda-Filho et al., (1995)
avaliaram o efeito da amônia e do nitrito sobre o crescimento da tainha e concluíram que
a tainha é um organismo passível de ser aproveitado em sistemas de cultivo desde que os
níveis de amônia total sejam inferiores a 4 mg/l, visto que o crescimento é reduzido em
concentrações superiores a esta. Neto e Spach (1998/1999) propuseram um protocolo
para criação de tainhas em água doce.
Sampaio et al. (2001) sugerem uma densidade de
estocagem entre três a cinco juvenis por litro em cultivo de laboratório. A toxicidade
aguda da amônia e do nitrito para juvenis de tainha é maior em água doce do que em
salinidades mais elevadas (Sampaio et al., 2002). Okamoto et al. (2006) observaram que
as tainhas crescem melhor em temperaturas de 30°C.
Ito e Barbosa (1997) observaram melhor crescimento de M. platanus alimentados com
uma dieta contendo 40% proteína bruta (PB) do que quando alimentados com um nível de
proteína inferior (20% PB). As dietas foram elaboradas com farinha de peixe, farinha de resíduos
3
de camarão, farelo de soja, fubá de milho, levedura seca de álcool de cana de açúcar, farelo de
trigo e farelo de arroz.
Alguns estudos sobre o processo de digestão foram realizados com larvas e
juvenis de M. platanus. O desenvolvimento estrutural do sistema digestório de larvas da
tainha M. platanus foi estudado por Galvão et al. (1997a) com o objetivo de aprimorar o
seu manejo alimentar. O desenvolvimento do trato digestório das larvas de tainha foi
considerado lento e a substituição de organismos vivos por dietas artificiais só é possível
ao redor do 40° dia após a sua eclosão, quando o trato digestório torna-se completamente
funcional, com a diferenciação do estômago e o aparecimento de glândulas gástricas.
Larvas de M. platanus com quatro dias de vida já apresentam as enzimas tripsina e
carboxipeptidases, embora suas atividades proteolíticas sejam baixas em relação aos
juvenis (Galvão et al., 1997b).
Apesar destes estudos, ainda há carência de informação acerca das exigências
nutricionais da M. platanus para que se possa desenvolver um protocolo alimentar
adequado, a fim de possibilitar sua criação intensiva.
As exigências nutricionais de um organismo estão relacionadas com a espécie,
fase de desenvolvimento, sexo e estádio de maturação sexual, sistema e regime de
produção, temperatura da água, frequência de arraçoamento e qualidade da dieta
(Watanabe, 1988; Pezzato et al., 2004), sendo o valor nutricional desta dieta determinada
pela sua digestibilidade e absorção pelo animal.
O primeiro passo para determinar as exigências nutricionais de uma espécie é
estimar a exigência de proteína (Gao et al., 2005, Martínez-Palacios et al., 2007). Este é o
nutriente mais caro da dieta e possui grande importância biológica, desempenhando uma
grande variedade de funções: atividade enzimática, transporte (hemoglobina), proteínas
4
nutrientes e de reserva, proteínas contráteis ou do movimento (miosina, actina), proteínas
estruturais, de defesa, reguladoras (hormônios) (Pezzato et al., 2004). No trato digestório
as proteínas são hidrolizadas enzimaticamente, liberando aminoácidos que são
distribuídos através da corrente sanguínea para os órgãos e tecidos, onde são utilizados
continuamente no processo de síntese e degradação protéica durante os processos de
crescimento, reprodução, ou como fonte de energia (Watanabe, 1988).
As diferenças nas exigências de proteína pelos organismos estão diretamente
relacionadas com os hábitos alimentares, tamanho do peixe e funcionalidade do aparelho
digestório. Animais carnívoros exigem altas quantidades de proteína na dieta para que
sejam obtidos os aminoácidos necessários para a síntese protéica e glicose para atender a
demanda energética (Sánchez-Muros et al., 1998), como Paralichthys olivaceus (45%
PB, Lee et al., 2002), Epinephelus coioides (48% PB, Luo et al., 2004). Já outras espécies
onívoras como os ciprinídeos, as tiláidas e alguns ictalúrideos, são capazes de manter as
taxas de crescimento quando alimentadas com dietas contendo 30% a 40% de proteína
bruta (NRC, 1993; Jobling, 1994). Hafedh (1999) verificou que dietas com nível protéico
de 30% e 40% foram satisfatórias para tilápias Oreochromis niloticus L. com 96 – 264g e
0.51g, respectivamente, demonstrando a alteração na exigência protéica em função do
tamanho dos peixes.
O nível de proteína na ração e a quantidade de alimento ofertado são um dos
principais fatores que influenciam o crescimento dos peixes, a eficiência alimentar e a
qualidade da água (Jana et al., 2006, Mohanta et al., 2008), entretanto o perfil de
aminoácidos presentes na proteína é decisivo para sua qualidade e determina seu valor
como componente da dieta. Além dos aminoácidos, a garantia de obtenção de uma ótima
5
resposta produtiva e máximo crescimento em peixes depende do atendimento das
necessidades protéico-energéticas e demais nutrientes essenciais nas proporções
necessárias (NRC, 1993).
Vidotti et al. (2000) testaram diferentes teores protéicos e relações de proteína de
origem animal em dietas para juvenis do bagre africano Clarias gariepinus e constataram
que o bagre é uma espécie exigente com relação a qualidade e quantidade de proteína na
dieta, visto que os melhores valores de ganho em peso foram obtidos para dietas com
38% de proteína bruta e com metade da proteína de origem animal. A maior proporção de
proteína de origem animal na dieta deve ter melhorado consideravelmente a qualidade da
dieta com relação ao perfil de aminoácidos essenciais e também com relação a sua
palatabilidade.
Dietas com níveis protéicos que excedam as exigências para crescimento,
resultam em um aumento no custo energético para deaminação dos aminoácidos em
excesso. Estes são convertidos em compostos energéticos, isto é, as cadeias carbônicas
dos aminoácidos são utilizadas para síntese de açúcares e/ou gorduras (Melo et al., 2006).
Esta proteína que é usada como fonte de energia, não é utilizada para o crescimento
(Horn et al., 1995, Lee et al., 2002, Mohanta et al., 2008). A amônia é o principal produto
da excreção de compostos nitrogenados dos peixes, o excesso de proteína na dieta, ou a
baixa qualidade da proteína (balanço inadequado de aminoácidos) resultam em um
aumento na excreção de amônia (Merino et al., 2007).
O excesso de energia não protéica, como resultado da formulação de dietas com
uma baixa relação proteína/energia, não é desejável tanto do ponto de vista dos índices de
conversão alimentar, de rentabilidade da dieta, como também porque leva a diminuição
6
do consumo voluntário do alimento e, com isso, há uma menor ingestão de proteína e
outros nutrientes essenciais podendo ocorrer excessiva deposição de gordura corporal
(Lee et al., 2002).
Embora os lipídios sejam reconhecidos como a principal fonte de energia não
protéica para peixes, a disponibilidade e o baixo custo dos carboidratos encorajam a sua
inclusão em dietas para atender racionalmente as suas exigências (Hillestad et al, 2001,
Martino et al., 2005). Os peixes não têm uma exigência dietética para carboidratos,
devido à capacidade de sintetizá-los a partir de substratos como proteínas e lipídios
através da gliconeogênese (Pezzato et al., 2004). As espécies onívoras tendem a utilizar
mais eficientemente o carboidrato do que as espécies carnívoras. Contudo, espécies
carnívoras mostram uma melhora no crescimento quando alimentadas com uma dieta
com pouco carboidrato quando comparadas com uma dieta sem adição de carboidrato
(Hemre et al., 2002). Portanto, a inclusão de carboidrato nas dietas pode proporcionar
uma ação poupadora da proteína como fonte energética direcionando-a para o
crescimento (Martino et al., 2005).
Considerando a importância da proteína na formulação de rações para peixes, o
objetivo do presente estudo foi determinar o nível de exigência protéica para juvenis de
M. platanus alimentadas com dietas isocalóricas contendo cinco níveis crescentes de
proteína.
7
2. Objetivos
Objetivo geral:
Determinar a exigência protéica para juvenis de tainha M. platanus alimentadas
com dietas isocalóricas contendo cinco níveis crescentes de proteína.
Objetivos específicos:
Avaliar o crescimento, sobrevivência, eficiência protéica de juvenis de tainha M.
platanus alimentados com dietas isoenergéticas contendo cinco níveis crescentes de
proteína.
Avaliar a composição corporal de juvenis de tainha M. platanus alimentados com
dietas isoenergéticas contendo cinco níveis crescentes de proteína.
Avaliar diferenças nos níveis de excreção de amônia de juvenis de tainha M.
platanus alimentados com dietas isoenergéticas contendo cinco níveis crescentes de
proteína.
8
3. Referências Bibliográficas
Benetti, D.D. e Fagundes Netto, E.B., 1991. Preliminary results on growth of mullets
(Mugil liza e Mugil curema) fed artificial diets. World Aquac. 22, 115-122.
Galvão, M.S.N., Fenerich-Verani, N., Yamanaka, N., Oliveira, I.R., 1997a. Histologia do
sistema digestivo da tainha Mugil platanus Günther, 1880 (Osteichhtys, Mugilidae)
durante as fases larval e juvenil. Bol. Inst. Pesca 24, 91–100.
Galvão, M.S.N., Yamanaka, N., Fenerich-Verani, N., Pimentel, C.M.M., 1997b. Estudos
preliminares sobre enzimas digestivas proteolíticas da tainha Mugil platanus Günter,
1980 (Osteichthyes, Mugilidae) durante as fases larval e juvenil. Bol. Inst. Pesca 24,
101-110.
Gao, Y., LV, J., Lin, Q., Li, L., 2005. Effect of protein levels on growth, feed utilization,
nitrogen and energy budget in juvenile southern flounder, Paralichthys lethostigma.
Aquac. Nut. 11, 427-433.
Godinho, H.M., Dias, E.R.A., Jacobsen, O., 1982. The effect of hormone in the induced
spawning of Mugil liza Val. from the lagunar region of Cananeia (25°21’S).
Atlântica 5, 48-49.
Godinho, H.M., Dias, E.R.A., Jacobsen, O., 1984. Reprodução induzida de tainha Mugil
liza Valenciennes, 1836 da região de Cananéia, São Paulo, Brasil (25°21’S). In:
Simpósio Brasileiro de Aquicultura, São Carlos, SP, Brasil, Anais do 3° Simpósio
Brasileiro de Aquicultura pp. 661–667.
9
Godinho, H.M., Serralheiro, P.C., Scorvo Filho, J.D., 1988. Revisão e discussão sobre as
espécies do genêro Mugil (Teleostei, Perciformes, Mugilidae) da costa brasileira (Lat
3°S – 33°S). Bol. Inst. Pesca 15, 67–80.
Godinho, H.M., 2005. Tainha. In: Baldisseroto, B. E Gomes, L. C (Org). Espécies nativas
para piscicultura no Brasil. UFSM, Santa Maria, pp. 433–441.
Hafedh, Y.S.A., 1999. Effects of dietary protein on growth and body composition of Nile
tilapia, Oreochromis niloticus L. Aquac. Res. 30, 385–393.
Hemre, G-I., Mommsen, T.P., Krogdahl, A., 2002. Carbohydrates in fish nutrition:
effects on growth, glucose metabolism and hepatic enzymes. Aquac. Nut., 8, 175–
194.
Hillestad, M., Johnsen, F., Åsgård, T., 2001. Protein to carbohydrate ratio in high-energy
diets for Atlantic salmon (Salmo salar L.). Aquac. Res. 32, 517–529.
Horn, M.H., Mailhiot, K.F., Fris, M.B., McClanahan, L. L., 1995. Growth, consumption,
assimilation and excretion in the marine herbivorous fish Cabidichthys violaceus
(Girard) fed natural and high protein diets. J. Exp. Mar. Biol. Ecol. 190, 97–108.
Ito, K., Barbosa, J.C., 1997. Nivel protéico e proporção de proteína de origem animal em
dietar artificiais para a tainha, Mugil platanus. Bol. Inst. Pesca 24, 111–117.
Jana, S.N., Garg, S.K., Barman, U.K., Arasu, A.R.T., Patra, B.C., 2006. Effect of varying
dietary protein levels on growth and production of Chanos chanos (Forsskal) in
inland saline groundwater: laboratory and field studies. Aquac. Int. 14, 479-498.
Jobling, M., 1994. Nutrional requirements. In: Fish Bioenergetics. Chapman & Hall p.
31–53.
10
Lee, S.M., Park, C.S., Bang, I.C., 2002. Dietary protein requirement of young Japanese
flounder Paralichthys olivaceus fed isocaloric diets. Fish. Sci. 68, 158–164.
Luo, Z., Liu, Y.J., Mai, K.S., Tian, L.X., Liu, D.H., Tan, X.Y., 2004. Optimal dietary
protein requirement of grouper Epinephelus coiodes juveniles fed isoenergetic diets
in floating net cages. Aquac. Nut. 10, 247–252.
Martínez-Palacios, C.A., Ríos-Durán, M.G., Ambriz-Cervantes, L., Jauncey, K.J., Ross,
L.G., 2007. Dietary protein requirement of juvenile Mexican silverside (Menidia
estor Jordan 1879), a stomachless zooplanktophagous fish. Aquac.Nut. 13, 304–310.
Martino, R.C., Cyrino, J.E.P., Portz, L., Trugo, L.C., 2005. Performance, carcass
composition and nutrient utilization of surubim Pseudoplatystoma coruscans
(Agassiz) fed diets with varying carbohydrate and lipid levels. Aquac. Nut. 11, 131-
137.
Melo, J.F.B., Lundstedt, L.M., Metón, I., Baanante, I.V., Moraes G., 2006. Effects of
dietary levels of protein on nitrogenous metabolism of Rhamdia quelen (Teleosei:
Pimelodidae) Comp. Bioch. Physiol. A 145: 181-187.
Menezes, N.A., Figueiredo, J.L., 1985. Manual de peixes marinhos do Sudeste do Brasil
V. Teleostei (4). Museu de zoologia universidade de São Paulo. p. 19–24.
Merino, G.E., Piedrahita, R.H., Conklin, D.E., 2007. Ammonia and urea excretion rates
of California halibut (Paralichthys californicus, Ayres) under farm-like conditions.
Aquaculture 271, 227–243
Miranda-Filho, K.C., Wasielesky-Jr, W., Maçada, A.P., 1995. Efeito da amônia e nitrito
no crescimento da tainha Mugil platanus (Piscies, Mugilidae). Rev. Brasil. Biol. 55,
45–50.
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Mohanta, K.N., Mohanty, S.N., Jena, J.K., Sahu, N.P., 2008. Protein requirement of
silver barb, Puntius gonionotus fingerlings. Aquac. Nutr. 14, 143-152.
National Research Council (NRC), 1993. Nutrient requirements of fish. National
Academy Press, Washington, DC, USA, 124p.
Neto, J.C.F., Spach, H.L., 1998/1999. Sobrevivência de juvenis de Mugil platanus
Günther, 1880 (Pisces, Mugilidae) em diferentes salinidades. Bol. Inst. Pesca 25, 13-
17.
Okamoto, M.H., Sampaio, L.A., Maçada, A.P., 2006. Efeito da temperatura sobre o
crescimento e a sobrevivência de juvenis da tainha Mugil platanus Günther, 1880.
Atlantica 28, 61-66.
Oliveira, I.R., Soares, L.S.H., 1996. Alimentação da tainha Mugil platanus Günther, 1880
(Pisces: Mugilidae), da região estuarino-lagunas de Cananéia, São Paulo, Brasil. Bol.
Inst. Pesca 23, 95–104.
Pezzato, L.E., Barros, M.M., Fracalossi, D.M., Cyrino, J.E.P., 2004. Nutrição de peixes.
In: Cyrino, J.E.P., Urbinati, E.C., Fracalossi, D.M. and Castagnolli., N. (Eds.).
Tópicos especiais em piscicultura de água doce tropical intensiva. Sociedade
Brasileira de Aqüicultura e Biologia Aquática, Jaboticabal, SP, p. 75–170.
Reis, E.G., Vieira, P.C., Duarte, V.S., 1994. Pesca artesanal de teleóteos no estuário da
Lagoa dos Patos e costa do Rio Grande do Sul. Atlântica 16, 69-86.
Reis, E.G., D’Incao, F., 2000. The present status of artisanal fisheries of extreme
Southern Brazil: an effort to wards community-based management. Ocean Coast.
Manage. 43, 585-595.
12
Rocha, I.P., 1981. Procedimentos básicos para a desova induzida e obtenção de alevinos
de peixes mugilídeos. In: Congresso Brasileiro de Engenharia de Pesca, Recife,
Brasil. Anais do 2 Congresso Brasileiro de Engenharia de Pesca pp. 451–461.
Sampaio, L.A., Ferreira, A.H., Tesser, M.B., 2001. Effect of stocking density on
laboratory rearing of mullet fingerlings, Mugil platanus (Günther, 1880). Acta Sci.
23, 471–475.
Sampaio, L.A., Wasielesky, W., Miranda-Filho, K.C., 2002. Effect of salinity on acute
toxicity of ammonia and nitrite to juvenile Mugil platanus. Bull. Env. Cont. Tox. 68,
668–674.
Sánchez-Muros, M.J., García-Rejón, L., García-Salguero, L., laHiguera, M., Lupiáñez,
J.A., 1998. Long-term nutritional effects on the primary liver and kidney metabolism
in rainbow trout. Adaptive response to starvation and a high-protein, carbohydrate-
free diet on glutamate dehydrogenase and alanine aminotransferase kinetics. Inter. J.
Biochem. Cell Biol. 30, 55–63.
SOFIA, 2006. The State of world fisheries and aquaculture.
http://www.fao.org/docrep/009/a0699e/A0699E00.HTM
Scorvo Filho, J.D., Paiva, P., Horikawa, M.T., Barros, H.P., Bastos, A.A., 1988.
Ocorrência de alevinos de mugilídeos na região de Ubatuba (23°32’S - 45°04’W),
Estado São Paulo, Brasil. Bol. Inst. Pesca 15, 213-220.
Vidotti, R.M., Carneiro, D.J., Malheiros, E.B., 2000. Diferentes teores protéicos e de
proteína de origem animal em dietas para o bagre africano, Clarias gariepinus
(Burchell, 1822) na fase inicial. Acta Sci. 22, 717-723.
13
Vieria, J.P., Scalabrin, C., 1991. Migração reprodutiva da tainha Mugil platanus Günther
1880 no sul do Brasil. Atlântica, 13, 131-141.
Watanabe, T., 1988. Fish Nutrition and Mariculture. The general aquaculture course.
Kanagawa International Fisheries Training Centre. Japan International Cooperation
Agency (JICA) 233 p.
14
4. ARTIGO ANEXO
The dietary protein requirement of juvenile mullet Mugil platanus (Günther, 1880)
Cristina V. A. de Carvalho, Adalto Bianchini, Marcelo B. Tesser, Luís A. Sampaio.
Segundo normas da revista “AQUACULTURE”.
15
The dietary protein requirement of juvenile mullet Mugil platanus
Cristina V. A. de Carvalho
1
, Adalto Bianchini
2
, Marcelo B. Tesser
1
, Luís A. Sampaio
1
*.
1
Universidade Federal do Rio Grande, Instituto de Oceanografia, Laboratório de
Piscicultura Marinha, Rio Grande-RS, CP 474, Brasil, CEP 96201-900, Brasil. + 55 53
32368131; +55 53 32368042
2
Universidade Federal do Rio Grande, Instituto de Ciências Biológicas, Laboratório de
Zoofisiologia, Av. Itália km 8, Campus Carreiros, Rio Grande-RS, 96201-900, Brasil. +
55 53 32336853; +55 53 32336848
*Corresponding author: [email protected]
16
Abstract
Feed is one of the main costs for fish culture. Studies looking for higher feed efficiency
are important to increase the success of aquaculture and reduce impacts of nutrient
emission into the environment. Considering the potential of the mullet Mugil platanus for
aquaculture, as well as the lack of information on its nutritional demands, the main goal
of the present work was to determine the dietary protein requirement of juvenile mullets.
Five isocaloric diets were formulated in order to contain increasing levels (30, 35, 40, 45,
and 50%) of crude protein (CP) corresponding to 18.7 MJ metabolizable energy/Kg. All
diets were tested in triplicate. Each experimental unit was composed of a 50 L tank with
50 juveniles (mean ± SE initial weight and length equal to 1.17 ± 0.02 g and 4.34 ± 0.03
cm, respectively). Diets were offered five times a day until apparent satiation for 35 days.
No significant difference (P > 0.05) was observed in survival rate, feed efficiency and
body composition between treatments. However, weight increase, feed ingestion and
specific growth rate was higher in fish fed the 35% CP level than those fed the highest
protein content diet (50% CP). The amount of postprandial ammonia excreted by mullet
was linearly related to protein intake. Intestinal tryptic activity was inversely proportional
to the percentage of dietary CP. The dietary protein requirement of juvenile mullet was
estimated as 34.28% CP with a P:E ratio of 18.7 g/MJ.
Keywords: diet, excretion, feeding, fish, growth, nutrition, protein
17
1. Introduction
Fish of the Mugilidae family, known as mullets, are found worldwide in tropical
and subtropical waters, especially in coastal and estuarine regions (Menezes and
Figueiredo, 1985). Mullets have been considered to be amongst the most promising
species for coastal aquaculture (Khemis et al., 2006). Also, their low position on the food
web suggest a high potential for extensive culture, being reared either in monoculture or
polyculture with other fishes and crustaceans (Benetti and Fagundes Netto, 1991).
The mullet Mugil platanus is of great economical importance for estuarine
artisanal fisheries in Southern Brazil (Reis and D’Incao, 2000). It is being considered for
aquaculture, since Godinho et al. (1993) demonstrated the feasibility to obtain induced-
spawning with HCG. Juvenile M. platanus is euryhaline (Sampaio et al., 2002) and
eurythermic (Okamoto et al., 2006), which are important features for coastal and
estuarine aquaculture.
The knowledge of the nutritional requirements for M. platanus is limited.
Considering that juveniles are iliophagus and feed on detritus and organic matter
(Oliveira and Soares, 1996), it is expected a low dietary protein requirement. Ito &
Barbosa (1997) compared the performance of juvenile M. platanus fed on two dietary
protein levels (20 and 40% crude protein) and verified a higher growth rate for mullets
fed on the higher protein content diet.
Appropriate levels of high quality protein generally result in high protein
efficiency rate. However, when the protein level is excessively increased relative to the
energy content of the diet, its excess can be catabolized and used as energy source. This
18
process results in reduced growth rate and increased ammonia excretion, which could be
harmful to fish health and the environment (McGoogan and Gatlin III, 1999).
Since protein is the most expensive component of fish diets, determination of the
optimum protein requirement can lead to the development of a diet that will provide high
growth rates at a minimum cost (Lee et al., 2002).
Considering the importance of protein in fish feed formulations and the poor
understanding of protein requirement for juvenile M. platanus, the objective of the
present study was to estimate the optimum dietary protein level for juvenile M. platanus
when fed isoenergetic semi-purified diets under controlled laboratory conditions.
2. Materials and Methods
2.1 Experimental procedures
Juvenile mullets were captured at Cassino Beach (Rio Grande – RS, Brazil;
32°17’S - 52°10’W) and transferred to the Laboratory of Marine Fish Culture of the
Federal University of Rio Grande (Southern Brazil), where they were stocked for two
weeks in a circular tank (1,000 L) containing sea water. They were randomly distributed
in 15 fiberglass tanks (50L), at a stocking density of 1 individual per liter (Sampaio et al.,
2001). Mullets were fed a commercial diet (INVE) on the first week. Food was supplied
until apparent satiation. On the following week, they were fed with the intermediate
protein level experimental diet (40% CP) five times a day, until apparent satiation. This
procedure was performed to adapt fish to the semi-purified diets.
19
At the beginning of the experiment and every week, 15 fish from each tank were
sampled, anesthetized with 50 ppm benzocaine, and individually measured and weighed.
After these procedures, fish were returned to their respective tanks. Initial total length and
weight was 4.34 ± 0.03 cm and 1.17 ± 0.02 g, respectively. There was no significant
difference of initial biomass among tanks (P > 0.05). Feeding was suspended 12 h before
weight measurements, and mullet resumed feeding immediately after they were returned
to their tanks. Dead fish were removed daily from the tanks. At the end of the
experiment, all surviving fish were counted to estimate final survival.
Experimental diets were offered until apparent satiation five times a day at 8:00,
11:00, 14:00, 17:00 and 20:00 h. The amount of food consumed in each tank was
registered everyday.
Water quality was monitored everyday. Temperature and dissolved oxygen were
measured with an oxymeter (YSI, model 55 Hexis), pH was measured with a pH meter
(Hanna Instruments, model HI 221), salinity was measured with a hand-refractometer
(Atago, model 103), while ammonia and nitrite concentrations were determined by
colorimetric methods (APHA, 2005). Average water temperature, salinity, pH, dissolved
oxygen, and ammonia and nitrite concentrations during the experiment was 24.0 ± 0.2°C,
29 ± 0‰, 7.93 ± 0.01, 5.67 ± 0.04 mg O
2
/L, 0.43 ± 0.02 mg TAN-N/L and 0.08 ± 0.01
mg NO
2
-N/L, respectively.
Detritus deposited at the bottom of the tanks were siphoned out daily. Each tank
was maintained in a flow-through system, with a water exchange rate of 0.8 l/min
(~100%/h). Tanks were covered with a net in order to prevent fish from jumping off.
20
Photoperiod was fixed at 14 h-light/10 h-dark. Water was constantly aerated through air
stone. Temperature was kept constant by means of a water bath.
2.2 Experimental diets
Five semi-purified diets with increasing crude protein (CP) concentrations of 30,
35, 40, 45 and 50% (dry weight) were tested. Diets were formulated to be isoenergetic
[18.7 MJ estimated metabolizable energy (ME)/Kg] (Table 1). As digestible energy
values for the ingredients used have not been determined for M. platanus, the dietary ME
was estimated based on standard physiological fuel values of 16.7 MJ/kg for
carbohydrate and protein and 37.7 MJ/kg for lipid (Garling and Wilson, 1976). In order
to keep the diets isoenergetic, the level of dextrin was reduced accordingly to the protein
increase.
Diets were prepared by initially mixing and homogenizing the dry ingredients and
subsequently adding oil. After humidification of the mixture with distilled water at 50°C,
the homogenate was forced through a meat grinder with 2 mm-diameter holes.
Afterwards, pellets were dried in an oven at 50°C for 15 h, broken and sieved through 2
mm sieves. Diets were stored in hermetically-sealed plastic bags in a freezer (-20°C) until
use.
2.3. Diet and whole-body composition analyses
The composition of the experimental diets is shown in Table 1
. Diet dry matter
was obtained by keeping samples at 105°C for 5 h. Ash content was determined after
sample incineration at 550°C. Lipid content was determined by ether extraction with a
Soxhlet extractor. Crude protein content was determined by the Kjeldahl method (N x
21
6.25) with the Kjeltec System (Tecator, Sweden). All analyses followed the AOAC
(1995) standard procedures.
Thirty fish were sampled at the beginning of the experiment. At the end of the
experiment (day 35), ten juveniles were sampled from each tank for whole body
composition analyses. Mullets were individually weighed, sacrificed on ice and frozen (-
20°C) until analysis. Fish sampled from each tank were pooled, grinded, homogenized,
and had their body composition analyzed. Moisture, ash, fat and crude protein content
were determined accordingly to the same procedure described for the diet analyses
(AOAC, 1995). Proximal compositions of diets and fish whole body were performed in
triplicate.
2.4 Postprandial ammonia excretion
At the end of the feeding trial, remaining fish were not fed for a period of 48 h to
ensure complete evacuation of any food from the gut. On the morning of the third day,
tanks were thoroughly cleaned, water was 100% renewed and water flow was
discontinued. Afterwards, fish in all tanks were fed the appropriate diet until apparent
satiation for 1 h and debris were siphoned out. The amount of diet ingested by fish in
each tank was registered. Total ammonia (TAN) was determined before fish were fed and
then 4 h after feeding, following the method described by APHA (2005). Excretion rates
were calculated based on the difference between final and initial concentration of TAN,
using the following equation: excretion rate = [(C
f
– Ci)] x V/ (W x t), where: C
f
is the
final TAN concentration (mg L
-1
); Ci is the initial TAN concentration (mg L
-1
); W is the
wet body weight (kg) of the fish; t is the time (h). Water temperature, salinity, dissolved
22
oxygen concentration and pH during the 24 h were 24 ± 0.5°C, 28.8 ± 0.0‰, 5.40 ± 0.2
mg O
2
/L and 7.84 ± 0.0 respectively.
2.5. Trypsin assay
The effect of dietary protein level on the intestinal trypsin activity was evaluated
at the end of the experiment. Three juveniles were sampled from each tank and
immediately frozen in liquid nitrogen (–196°C). The intestine was dissected on a ice plate
and processed in a Potter micro-homogenizer (1mg sample/2 µl buffer) using cold Tris-
HCl buffer (0.1 M, pH 8.0) containing CaCl
2
(0.02 M). The homogenate was centrifuged
at 6,000 x g for 60 min at 4°C (Micro 22R, Hettich Zentrifugen, Global Medical
Instrumentation, Ramsey, MN, USA). The supernatant was used for enzyme activity
assays and protein content analysis. Tryptic activity measurement was performed using a
fluorescence technique adapted from Ueberschär (1988). The reaction was performed
with 250 µL of Nα-carbobenzoxy-L-arginine-4-methylcoumarinyl – 7–amide (CBZ –L-
Arg-MCA) solution (0.2 mM) as substrate and 10 µL of sample supernatant. Increase in
fluorescence emission at 450 nm (excitation at 355 nm) was measured every 2 min for 30
min (Victor 2, Perkin-Elmer, Waltham, MA, USA). Only the linear portion of the
fluorescence response over time was considered for enzyme activity calculations. Trypsin
activity was normalized by the protein concentration in the sample supernatant. Protein
was determined using a commercial reagent kit (Proteínas Totais® ; Doles, Goiânia, GO,
Brazil) based on the Biuret assay. Trypsin activity was expressed as ng trypsin/mg
protein.
23
2.6. Performance parameters
Effects of different dietary protein levels in juvenile mullets were evaluated using
the following parameters: survival (S) = [(initial number of fish – number of dead
fish)/(initial number of fish) x 100], weight gain (WG) = (final weight – initial weight),
specific growth rate (SGR) = [(ln final weight – ln initial weight)/(day) x 100], feed
efficiency (FE) = weight gain/feed intake (dry matter – DM), feed intake (FI) = feed
intake (DM)/fish, protein intake (PI) = protein intake (DM)/fish, protein efficiency ratio
(PER) = weight gain/protein consumption (DM) and apparent net protein utilization
(ANPU) = 100 x [(final weight x final body protein content) – (initial weight x initial
body protein content)]/(total dry protein intake).
2.7 Experimental design, statistical analysis and estimation of protein
requirement
The experimental design was entirely randomized, with five treatments (30, 35,
40, 45 and 50% CP) tested in triplicate. Data obtained are expressed as mean ± standard
error. Before statistical procedures, data were tested for homogeneity of variance and
normality using Levene’s test and Kolmogorov-Smirnov test, respectively. Data were
subjected to one-way analysis of variance (ANOVA) followed by the Tukey’s HSD test
when significant differences were detected. A significance level of 95% was adopted in
all tests. The relationship between protein intake and postprandial ammonia excretion rate
and between protein content of the diet and trypsin activity was analyzed by linear
regression. In addition, the protein requirement was defined as 95% of the maximum
weight gain estimated by quadratic regression (Jobling, 1994).
24
3. Results
Proximate body composition of juvenile mullet fed diets with different dietary
protein content is summarized in Table 2. Fish whole body protein, fat, ash and moisture
contents were not influenced by dietary protein level (P > 0.05).
Survival was not influenced by the protein level of the diets (P > 0.05), albeit not
significant, there was a trend for reduced survival of fish fed the diet with the highest
protein content (Table 3).
The present study was based on a dose-response design. Specific growth rate of
juvenile mullet fed diets containing 35% CP was significantly higher (P < 0.05) than fish
fed 50% CP diet. However, it did not differ (P > 0.05) between diets with 30, 35, 40, and
45% CP (Table 3). Growth difference between fish fed different CP diets occurred only
after 3 weeks of study and the same trend continued until the end of the experiment
(Figure 1). Weight gain followed the same trend and its relation with the protein content
of the diets was described by a quadratic model, where the dietary protein requirement of
juvenile mullet was estimated at 34.2% (Figure 2).
Feed intake was significantly higher for fish fed diets with 30 and 35% CP
compared to those fed the highest dietary protein content (50% CP). Despite the tendency
of lower feed intake of diets with protein concentration higher than 35% CP, protein
consumption increased (P < 0.05) as dietary protein content was raised (Table 3).
Feed efficiency did not change (P > 0.05) between fish fed the different
experimental diets. However, protein efficiency ratio (PER) was higher (P < 0.05) for
fish fed the lowest dietary protein level (30% CP) than for fish fed the highest dietary
25
protein content (50% CP). Apparent net protein utilization (ANPU) of fish fed diets
containing 30 and 35% CP was higher (P < 0.05) than of fish fed 45 and 50% protein
diets. However, these results did not differ significantly (P > 0.05) from ANPU of fish
fed the intermediate dietary protein content (40% CP) (Table 3).
It was observed an inverse relationship between the intestinal trypsin activity of
mullets and the dietary protein level (Figure 4).
The amount of protein ingested by juvenile mullets during the excretion trial was
influenced by the dietary protein. Feed intake of fish fed the diet with the highest protein
content (50% CP) was lower than all other treatments, and they actually ingested the
smallest amount of protein. Postprandial ammonia excretion was directly proportional to
the amount of protein ingested and it was adequately described by a linear model (Figure
3).
4. Discussion
Although not significantly different from the other treatments, fish mortality was
higher for mullets fed the highest dietary protein concentration (50% CP), but no obvious
causes were available to explain it. Higher mortalities were also registered for juvenile
Barbodes altus (Elangovan and Shim, 1997) and Paralichthys lethostigma (Gao et al.,
2005) when fed excess protein. According to Kiron et al. (1995), a low-protein diet
invariably resulted in greater mortality of Oncorhynchus mykiss, but higher levels
(around 50% CP) also seemed to depress disease resistance when compared with
intermediate protein range (20 - 35% CP).
26
The dietary protein levels tested did not affect final whole body composition of
M. platanus. Therefore, body composition is not an indicator of protein requirement for
juvenile mullets, whereas growth, PER and ANPU reflected the protein requirement.
Similar results have been found for juvenile Barbodes altus (Elangova and Shim, 1997)
and Menidia estor (Martínez-Palacios et al., 2007). On the other hand, body protein
content increased when the dietary protein level was above the minimum protein
requirement for Bidyanus bidyanus (Yang et al., 2002).
Weight gain of juvenile M. platanus increased with increasing dietary protein
level up to 35% CP. Thereafter, it was observed a trend for growth depression as the
protein content of the diet was raised, especially at 50% CP. Studies with several teleosts
have reported similar growth responses in fish, with manifestation of growth depression
in response to excessive levels of dietary protein (Papaparaskeva-Papoutsoglou and
Alexis, 1986; Horn et al., 1995; Elangovan and Shim, 1997; Yang et al 2002; Jana et al.,
2006; Martínez-Palacios et al., 2007).
Reduction of growth was accompanied by reduced food ingestion at higher
protein content diets. Feed consumption by Diplodus sargus was higher when they were
offered a diet with low protein content (17% CP) compared to a diet with a higher protein
level (27% CP), possibly trying to compensate the lower dietary protein content (Sá et al.,
2008). Similar result was observed by Horn et al. (1995), where Cebidichthys violaceus,
an herbivorous marine fish, markedly reduced their food consumption with an increase in
dietary protein. The same behavior was observed for Labeo rohita (Satpathy 2003) and
Puntius gonionotus (Mohanta et al., 2008).
27
It is important to notice that anorexia has been shown to be induced by excess
dietary protein. Veldhorst et al. (2008) listed four mechanisms that may contribute to the
protein-induced satiety: altered concentration of satiety hormones, increased energy
expenditure, higher concentration of metabolits (ie: amino acids) and gluconeogenesis.
Besides that, the proportion of protein to energy was increased as the protein content of
the diets increased. The higher protein to energy ratio also resulted in reduced growth for
other species, as the excess protein is used as energy source and not for growth (Horn et
al., 1995; Elangovan and Shim, 1997; Martínez-Palacios, 2007).
Energy content is thought to be one of the major criteria controlling feed intake in
fish (Lee and Putnam, 1973; Glencross, 2006; Mohanta et al., 2008), along with other
factors including fish size, temperature or food palatability. However, in the present work
fish were fed isoenergetic diets and seemed to control ingestion according to dietary
protein level, probably trying to adjust feed intake to meet their protein requirement
(Horn et al., 1995; Martínez-Palacios, 2007)
Feed efficiency of juvenile mullet was not affected by dietary protein level in the
present study. However, in other studies the increase in dietary protein above a
determined level produced a significant decrease in FE (Elangovan and Shim, 1997;
Yang et al., 2003).
Results from the present study indicated a reduction on PER with increasing
dietary protein content. Similar results were reported for Barboles altus (Elangovan and
Shim, 1997), Mystus nemurus (Ng et al., 2001), Spinabarbus hollandi (Yang et al., 2003),
and Paralichthys olivaceus (Kim et al., 2004). These authors suggested that protein in
excess to the amount needed for growth is catabolized and used as energy source. The
28
increased ammonia excretion observed for mullet fed excess protein corroborates this
idea. In the same manner, ANPU decreased linearly when the dietary protein level of the
diet was above 35%. Yang et al. (2002) also reported a higher ANPU for Bidyanus
bidyanus with a lower dietary protein intake.
Postprandial ammonia excretion can be an indicator of dietary protein adequacy
and it is directly related to protein intake (Merino et al., 2007). Usually, nitrogenous
excretion increases linearly with increasing feed consumption (Sun et al., 2006). Similar
results were found for Cebidichthys violaceus (Horn et al., 1995), Bidyanus bidyanus
(Yang et al., 2002) and the juvenile mullet in the present study.
Trypsin activity decreased with increasing dietary protein levels. A reduction in
trypsin activity has also been shown for other species when fish are fed diets with protein
content in excess of their requirement (Jana et al., 2006; Mohanta et al., 2008). Thus, the
actual protein requirement for juvenile mullet may be lower than it was estimated,
approaching 30% CP instead.
Dietary protein requirement vary between species, with carnivorous fish generally
showing higher values than omnivorous and herbivorous species (NRC, 1993).
Comparison of protein requirement among fish species is complicated due to differences
in fish size, diet formulation and culture conditions tested (Elangovan and Shim, 1997).
However, the minimum dietary protein required by M. platanus for maximum growth is
comparable to the protein requirements reported for juveniles of other omnivorous
species, such as Cyprinus carpio (35% CP; NRC 1993), Plecoglossus altivelis (38% CP;
Lee et al., 2002), Rhamdia quelen (37.3% CP; Meyer and Fracalossi, 2004) and Chanos
chanos (40% CP; Jana et al., 2006). However, Papaparaskeva-Papoutsoglou and Alexis
29
(1986) determined a very low protein requirement (24% CP) for juvenile Mugil capito,
while Yoshimatsu et al. (1992) estimated a higher dietary protein requirement (40% CP)
for juvenile Lisa haematocheila. Differences observed could be associated with
methodological procedures adopted in each study
Ito and Barbosa (1997) observed a higher growth rate of M. platanus when fed on
a diet containing 40% CP compared to a diet with lower protein content (20% CP).
However, it is also important to notice that optimum dietary requirement is higher for
young animals (Yoshimatsu et al., 1992), and as such, it is likely that diets containing less
than 34.2% CP will be needed for on-growing mullet, especially when reared in ponds
with abundant natural food.
Acknowledgements
C. V. A. Carvalho is a student of the Graduate Program in Aquaculture at FURG
and is supported by CAPES. A. Bianchini (# 300906/2006-4) and L.A. Sampaio (#
301673/2006-3) are research fellows of the Brazilian CNPq. This work was supported by
FAPERGS (06/14056) and CNPq (477171/2006-0) grants.
References
AOAC (Association of Official Analytical Chemists), 1995. Official Methods of
Analysis. Arlington, VA. 1298 p.
APHA (American Public Health Association), 2005. Standard Methods for the
Examination of Water and Wastwater, 21st Edition. Washington. 1193p.
30
Benetti, D.D., Fagundes Netto, E.B.F., 1991. Preliminary results on growth of mullets
(Mugil liza and Mugil curema) fed artificial diets. J. World Aquac. Soc. 22, 115-122.
Elangovan, A., Shim, K. F., 1997. Growth response of juvenile Barbodes altus fed
isocaloric diets with variable protein levels. Aquaculture 158, 321-329.
Gao, Y., LV, J., Lin, Q., Li, L., 2005. Effect of protein levels on growth, feed utilization,
nitrogen and energy budget in juvenile southern flounder, Paralichthys lethostigma.
Aquac. Nutr. 11, 427 - 433.
Garling, D.L.Jr., Wilson, R.P., 1976. Optimum dietary protein to energy ratio for channel
catfish fingerlings, Ictalurus punctatus. J. Nutr. 106, 1368 - 1375.
Glencross, B., 2006. The nutritional management of barramundi, Lates calcarifer – a
review. Aquac. Nutr. 12, 291–309.
Godinho, H.M., Kavamoto, E.T., Andrade-Talmelli, E.F.de, Serralheiro, P.C.S., Paive,
P., Ferraz, E.M., 1993. Induced spawning of the mullet Mugil platanus Günther,
1880, in Cananéia, São Paulo, Brazil. Bol. Inst. Pesca 20, 59-66.
Horn, M.H., Mailhiot, K.F., Fris, M.B., McClanahan, L.L., 1995. Growth, consumption,
assimilation and excretion in the marine herbivorous fish Cabidichthys violaceus
(Girard) fed natural and high protein diets. J. Exp. Mar. Biol. Ecol. 190, 97–108.
Ito, K., Barbosa, J.C., 1997. Nível protéico e proporção de proteína de origem animal em
dietas artificiais para a tainha, Mugil platanus. Bol. Inst. Pesca 24, 111 – 117.
Jana, S.N., Garg, S.K., Barman, U.K., Arasu, A.R.T., Patra, B.C., 2006. Effect of varying
dietary protein levels on growth and production of Chanos chanos (Forsskal) in
inland saline groundwater: laboratory and field studies. Aquac. Int.. 14, 479-498.
31
Jobling, M., 1994. Nutrional requirements. In: Fish Bioenergetics. Chapman & Hall p.
31–53.
Khemis, I. B., Zouiten, D., Besbes, R. and Kamoun, F., 2006. Larval rearing and weaning
of thick lipped grey mullet (Chelon labrosus) in mesocosm with semi-extensive
technology. Aquaculture 259, 190 – 201.
Kim, K.W., Wang, X., Choi, S.M., Park, G.J., Bai, S.C., 2004. Evaluation of dietary
protein-to-energy ratio in juvenile olive flounder Paralichthys olivaceous (Temminck
et Schlegel). Aquac. Res. 35, 250-255.
Kiron, V., Watanabe, T., Fukuda, H., Okamoto, N., Takeuchi, T., 1995. Protein nutrition
and defense mechanisms in rainbow trout Oncorhynchus mykiss. Comp. Biochem.
Physiol. A 111, 351-359.
Lee, D. J., Putnam, G. B., 1973. The response of rainbow trout to varying protein energy
ratios in a test diet. J. Nutr. 103, 916 - 922.
Lee, S.M., Kim, D.J., Cho, S.H., 2002. Effects of dietary protein and lipid level on
growth and body composition of juvenile ayu (Plecoglossus altivelis) reared in sea
water. Aquac. Nutr. 8, 53 - 58.
Martínez-Palacios, C.A., Ríos-Durán, M.G., Ambriz-Cervantes, L., Jauncey, K.J., Ross,
L.G., 2007. Dietary protein requirement of juvenile Mexican silverside (Menidia
estor Jordan 1879), a stomachless zooplanktophagous fish. Aquac. Nutr. 13, 304 –
310.
McGoogan, B.B., Gatlin III, D.M., 1999. Dietary manipulations affecting growth and
nitrogenous waste production of red drum, Scienops ocellatus I. Effects of dietary
protein and energy levels. Aquaculture 178, 333–348.
32
Menezes, N.A., Figueiredo, J.L., 1985. Manual de peixes marinhos do Sudeste do Brasil
V. Teleostei (4). Museu de Zoologia da Universidade de São Paulo, São Paulo, SP,
105pp.
Merino, G.E., Piedrahita, R.H., Conklin, D.E., 2007. Ammonia and urea excretion rates
of California halibut (Paralichthys californicus, Ayres) under farm-like conditions.
Aquaculture 271, 227–243.
Meyer, G., Fracalossi, D.M., 2004. Protein requirement of jundia fingerlings, Rhamdia
quelen, at two dietary energy concentrations. Aquaculture 240, 331–343.
Mohanta, K.N., Mohanty, S.N., Jena, J.K., Sahu, N.P., 2008. Protein requirement of
silver barb, Puntius gonionotus fingerlings. Aquac. Nutr. 14, 143-152.
National Research Council (NRC), 1993. Nutrient requirements of fish. National
Academy Press, Washington, DC, USA, 124p.
Ng, W.K., Soon, S.C., Hashim, R., 2001. The dietary requirement of bagrid catfish,
Mystus nemurus (Cuvier & Valenciennes), determined using semipurified diets of
varying protein level. Aquac. Nutr. 7, 45–51.
Okamoto, M.H., Sampaio, L.A., Maçada, A.P., 2006. Efeito da temperatura sobre o
crescimento e a sobrevivência de juvenis da tainha Mugil platanus Günther, 1880.
Atlântica 28, 61-66.
Oliveira, I.R., Soares, L.S.H., 1996. Alimentação da tainha Mugil platanus Günther, 1880
(Pisces: Mugilidae), da região estuarino-lagunar de Cananéia, São Paulo, Brasil. Bol.
Inst. Pesca 23, 95–104.
Papaparaskeva-Papoutsoglou, E., Alexis, M.N. 1986. Protein requirements of Young grey
mullet, Mugil capito. Aquaculture 52, 105-115.
33
Reis, E.G., D’Incao, F., 2000. The present status of artisanal fisheries of extreme
Southern Brazil: an effort to wards community-based management. Oc. Coast.
Manage. 43, 585-595.
Sá, R., Pousão-Ferreira, P., Oliva-Teles, A., 2008. Dietary protein requirement of white
sea bream (Diplodus sargus) juveniles. Aquac. Nutr. 14, 309-317.
Sampaio, L.A., Ferreira, A.H., Tesser, M.B., 2001. Effect of stocking density on
laboratory rearing of mullet fingerlings, Mugil platanus (Günther, 1880). Acta Sci.
23, 471–475.
Sampaio, L.A., Wasielesky, W., Miranda-Filho, K.C., 2002. Effect of salinity on acute
toxicity of ammonia and nitrite to juvenile Mugil platanus. Bull. Env. Cont. Tox. 68,
668–674.
Satpathy, B.B., Mukeherjee, D., Ray, A.K., 2003. Effects of dietary protein and lipid
levels on growth, feed conversion and body composition in rohu, Labeo rohita
(Hamilton), fingerlings. Aquac. Nutr. 9, 17–24.
Sun, L., Chen, H., Huang, L., Wang, Z., 2006. Growth, faecal production, nitrogenous
excretion and energy budget of juvenile cobia (Rachycentron canadum) relative to
feed type and ration level. Aquaculture 259, 211-221.
Ueberschär, B.F.R., 1988. Determination of the nutritional condition of individual marine
fish larvae by analyzing their proteolytic enzyme activities with a highly sensitive
fluorescence technique. Meeresforsch 32, 144-154.
Veldhorst, M., Smeets, A., Soenen, S., Hochstenbach-Waelen, A., Hursel, R., Diepvens,
K., Lejeune, M., Luscombe-Marsh,N., Westerterp-Plantenga, M., 2008. Protein-
34
induced satiety: Effects and mechanisms of different proteins. Physiol. Behav. 94,
300-307.
Yang, S-D., Liou, C-H., Liu, F-G., 2002. Effects of dietary protein level on growth
performance, carcass composition and ammonia excretion in juvenile silver perch
(Bidyanus bidyanus). Aquaculture 213, 363-372.
Yang, S.D., Lin, T.S., Liou, C.H., Peng, H.K., 2003. Influence of dietary protein levels
on growth performance, carcass composition and lipid classes of juvenile Spinibarbus
hollandi (Oshima). Aquac. Res. 34, 661-666.
Yoshimatsu, T., Furuichi, M., Kitajima, C. 1992. Optimum level of protein in purified
experimental diets for redlip mullet. Nippon Suisan Gakkaishi 58, 2111-2117.
35
Table 1. Formulation and proximate composition of experimental diets (% dry matter)
Dietary protein level (%)
30 35 40 45 50
Ingredient (g/100gdiet)
Fish meal
1
23 23 23 23 23
Casein
2
10 15 20 25 30
Gelatin
2
2 3 4 5 6
Dextrin
3
39.5 33.5 27.5 21.5 15.5
Cellulose
2
14.5 14.5 14.5 14.5 14.5
Fish oil
4
6.2 6.2 6.2 6.2 6.2
Min. and vit. premix
5
0.5 0.5 0.5 0.5 0.5
Corn starch 4.3 4.3 4.3 4.3 4.3
Proximate composition (% of 100% dry matter)
Dry matter 91.11 90.28 89.88 90.78 91.30
Crude protein 29.10 34.95 40.36 45.47 50.98
Crude fat 9.16 9.08 8.64 9.35 8.97
Ash 2.83 2.97 2.88 2.70 3.03
NFE
6
61.50 56.40 52.21 46.67 41.48
ME (MJ kg
-
1
)
7
18.6 18.7 18.7 18.9 18.8
P:E ratio
h
(g MJ
-
)
8
15.7 18.7 21.6 24.0 27.1
1
Fish meal contains (as % of dry matter): crude protein, 80; lipid, 11.8; ash, 9.01.
Nicoluzzi (Santa Catarina, RS, Brazil).
2
Synth (Diadema, SP, Brazil).
3
Rhoster (São
Paulo, SP, Brazil).
4
Campestre Ind. e Com. de Óleos Vegetais Ltda (São Paulo, SP,
36
Brazil).
5
Socil (São Paulo, SP, Brazil) composition/kg of premix: vit. A 1.000,000 UI,
vit. D3 500.000 UI, vit. E 20.000 UI, vit. K 500mg, vit. C 25.000 mg, vit. B1 500 mg,
vit. B2 1750 mg, vit. B6 1125 mg, Ca pantothenate 5000 mg, folic acid 250 mg, biotin 50
mg, niacin 5000mg, vit B12 24 mg, iron 13.700 mg, selenium 75 mg, copper 2000 mg,
zinc 20.000 mg, manganese 3.760 mg, iodine 100 mg, B.H.T. 250 mg, vehicle 1000 g.
6
Nitrogen-free extract (100% - %crude protein - %crude fat - %ash).
7
Metabolizable
energy, calculated from the physiological standard values, where 1kg of carbohydrate
(N–free extract), protein and lipid yields 16.7, 16.7 and 37.6 MJ, respectively (Garling
and Wilson, 1976).
8
Crude protein/metabolizable energy.
37
Table 2. Whole-body composition (% dry matter) of juvenile Mugil platanus after 35
days of feeding on diets containing increasing levels of dietary protein
1
.
Dietary protein
(%)
Dry matter (%) Crude protein (%) Crude fat (%) Ash (%)
30 28.36±0.1 53.02±1.3 34.91±0.2 13.22±0.0
35 28.92±0.1 56.29±0.8 34.69±0.4 13.49±0.3
40 28.24±0.2 54.06±0.5 34.17±0.5 13.11±0.0
45 28.82±0.0 55.73±0.2 33.34±0.4 13.45±0.1
50 28.88±0.1 56.33±0.6 34.17±0.5 13.97±0.0
1
Data are mean values (± standard error) of three replicates. Figures in the same column
were not significantly different (P > 0.05). Initial whole body composition was 26.01%
dry matter, 59.25% protein, 32.39% lipid and 15.83% ash.
38
Table 3. Survival, growth performance, and feed utilization by juvenile mullet Mugil
platanus fed diets containing graded levels of protein for 35 days
1
.
Parameters Dietary protein level (%)
30 35 40 45 50
Initial weight (g) 1.17±0.02
Survival (%)
97.5±0.6 95.7±3.4 96.3±2.2 98.8±0.6 88.4±2.6
ns
SGR (%)
3
3.59±0.1
ab
3.84±0.2
a
3.60±0.1
ab
3.40±0.1
ab
3.01±0.1
b
FE (%)
4
0.36±0.0 0.39±0.0 0.42±0.0 0.41±0.0 0.37±0.0
ns
FI (g/fish)
5
8.06±0.2
a
8.34±0.47
a
6.92±0.4
ab
6.94±0.4
ab
6.16±0.1
b
PI (g/fish)
6
2.34±0.1
b
2.92±0.1
ab
2.79±0.2
ab
3.16±0.2
a
3.14±0.1
a
PER
7
1.23±0.1
a
1.12±0.0
ab
1.04±0.1
ab
0.90±0.0
bc
0.74±0.1
c
ANPU (%)
8
62.00±4.5
a
62.89±0.9
a
53.92±0.9
ab
48.68±1.6
bc
40.38±3.3
c
1
Mean ± standard error of three replicates. Values within the same rows having different
superscripts are significantly different (P < 0.05), ns – non significant.
2
Survival = [(initial number of fish – number of dead fish)/(initial number of fish) x 100]
3
Specific growth rate = [(ln final weight – ln initial weight)/day] x 100.
4
Feed efficiency = [weight gain/ feed intake].
5
Feed intake = feed intake/ fish.
6
Protein intake = protein intake/ fish.
7
Protein efficiency ratio = [(weight gain/protein intake].
8
Apparent net protein utilization = [(final weight x final body protein) – (initial weight x
initial body protein)]/(total dry protein intake) x 100.
39
0 7 14 21 28 35
Days
0.0
1.0
2.0
3.0
4.0
5.0
Weight (g)
30% CP
35% CP
40% CP
45% CP
50% CP
b
a
b
b
ab
ab
ab
ab
ab
ab
a
a
ab
ab
ab
Figure 1. Growth of juvenile Mugil platanus fed diets containing increasing levels of
protein for 35 days. Values are mean
± standard error of triplicate feeding groups. Points
within the same day having different superscripts are significantly different (P < 0.05).
40
Figure 2. Relation between specific growth rate (%/day) and protein level for juvenile
mullet Mugil platanus as shown by a quadratic regression, protein requirement is equal to
95% of maximum weight gain. Each point represents mean
± standard error of triplicate
treatments.
Dietary crude protein %
25 30 35 40 45 50 55
Weight gain (g/fish)
1
2
3
4
95%
Ymax.
y = -0.004x
2
+ 0.302x - 2.364
R
2
= 0.63 P = 0.0196
41
y = 26.676x + 25.997
R
2
= 0.86 P = 0.0241
30
35
40
45
50
55
60
65
70
75
0,7 0,8 0,9 1,0 1,1 1,2 1,3 1,4
Protein intake (g)
Ammonia excretion rate )
(mg NH
3
- N/kg/h)
Figure 3. Postprandial ammonia excretion rate (mg NH
3
-N/kg/h) as a function of protein
intake for juvenile mullet Mugil platanus. Values are expressed as mean
± standard error.
42
y = -1.3417x + 129.2
R
2
= 0.92 P = 0.0103
40
50
60
70
80
90
100
110
120
25.0 30.0 35.0 40.0 45.0 50.0 55.0
Dietary crude protein (%)
Enzyme activity
(ng trypsin/mg proteins) )
Figure 4. Intestinal tryptic activity in juvenile mullet Mugil platanus fed diets containing
increasing levels of protein. Values are expressed as mean
± standard error.
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