Effects and Interactions of Stocking Density and Added Substrate on Production and Population Structure of Freshwater Prawns Macrobrachiurn rosenbergii
| Autor: | Shawn D. Coyle, Charles Webel, Jeff Evans, James H. Tidwell |
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| Rok vydání: | 1999 |
| Předmět: | |
| Zdroj: | Journal of the World Aquaculture Society. 30:174-179 |
| ISSN: | 1749-7345 0893-8849 |
| Popis: | The effects and interactions of added artificial substrate with different stocking densities of prawns were evaluated. Juvenile prawns (0.2 ± 0.1 g) were stocked into 12 0.04-ha ponds at 60,000ha and 120,000/ha with and without substrate. Added substrate consisted of horizontal plastic mesh and strips of “oyster netting” sutlicient to increase available surface area 80%. There were no statistically significant (P > 0.05) interactions between stocking density and presence of added substrate, allowing these main effects to be compared separately. Increasing stocking density produced a significant increase (P 20 g, -27%; > 30 g, -56%). Added substrate also produced a significant increase (P 20 g, 25%; >30 g, 19%). Feed conversion ratios were significantly decreased (P 0.05) on numbers of reproductive (RF) and virgin (VF) female morphotypes. Increased stocking density also produced a significant decrease (P 0.05) on the number or size of different morphotypes. The mathematical relationship between available surface area and average prawn size should be determined to produce recommended inclusion rates for added substrate based on desired levels of total production, stocking rates, and optimum market sizes. |
| Databáze: | OpenAIRE |
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