Effects of essential fatty acids and N and P-limited algae on the growth rate of tropical cladocerans |
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Authors: | Aloysio S Ferrão-Filho Cláudia Fileto Norberto P Lopes Marlene S Arcifa |
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Institution: | Instituto de Biofísica Carlos Chagas Filho, CCS, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Ilha do Fundão, RJ 21949–900, Brazil;Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP 14040–901, Brazil;Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP 14040–901, Brazil |
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Abstract: | SUMMARY 1. In this study, the effects of nutrient (N and P) deficiency and the importance of essential polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] to tropical cladocerans, growth and reproduction were determined in a growth bioassay. 2. The animals were fed N/P-sufficient, N-deficient and P-deficient algae, and also N and P-deficient algae supplemented with fish oil emulsions rich in EPA and DHA. 3. Cladocerans showed different responses to nutrient-deficient algae and also to supplements of fish oil emulsions. Moina micrura was most sensitive to P-deficient alga and, surprisingly, grew better and produced more eggs in N-deficient alga than in N/P sufficient alga. Ceriodaphnia cornuta was less sensitive, growing well in both N and P-deficient algae. This species, however, had a lower clutch size in N-deficient alga. On the other hand, Daphnia gessneri was the most sensitive to mineral limitation, showing decreased growth and clutch size in both nutrient-deficient algae. 4. The PUFA supplements to nutrient-deficient algae increased growth rates only for M. micrura and C. cornuta , suggesting that these fatty acids are important food requirements for these species. |
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Keywords: | docosahexaenoic acid eicosapentaenoic acid mineral limitation polyunsaturated fatty acids tropical zooplankton |
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