Nutritional effects of body composition, energy content and trypsin activity of Penaeus japonicus during early postlarval development
1998
Lemos, D. | Fernandez, Aurelio Rodriguez
The growth, elemental (C, N, H) and biochemical (lipid, protein) composition, energy content and trypsin activity of Penaeus japonicus early postlarvae (PL1-PL20, as days after metamorphosis) fed under a commercial hatchery regime were measured. From PL1 to PL4, freshly hatched Artemia nauplii were used, followed by enriched Artemia nauplii (PL5-PL9), and a prepared diet from PL10 to PL20. Survival for the total experimental period was 80% and daily gain in absolute values of dry weight, energy and elemental composition was observed. Significant increment (P < 0.05) of relative values of carbon, hydrogen and energy was verified from PL1 to PL3 as well as increases in protein and lipid content from PL1 to PL5. In the period PL10-PL20, carbon, hydrogen and energy content decreased significantly (P < 0.05). This may have been due to the poor quality of diet supplied after PL5, which possibly caused malnutrition. During this period, lipid was a major source of energy for the postlarvae. Body protein of postlarvae as determined by nitrogen content (N x 6.25) was overestimated after PL5, which indicates to a possible role of the non-protein nitrogen fraction under poor feeding conditions. Protein-specific trypsin activity showed significant increment (P < 0.05) at periods PL1-PL5 and PL15-PL20, which may indicate a possible influence of diet composition. It is concluded that this type of approach may be useful as a tool to assess the nutritional condition of cultivated shrimp, during postlarval stages.
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