http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Observed and modeled effects of salinity, temperature and dietary protein/energy on growth of juvenile Litopenaeus vannamei and on nitrogen dynamics in static culture systems
xvii, 193 leaves : illustrations ; 28 cm.
Laboratory experiments evaluated effects of salinity, temperature and dietary rotein/energy on aquacultural performance of juvenile Litopenaeus vannamei. Growth was faster at 25 ppt than at 5 or 40 ppt salinity. Higher protein requirement was indicated at 5 and 40 ppt than at 25 ppt. But 25% protein provided excellent growth for shrimp at all three salinities, provided the dietary protein-to-metabolizable energy ratio (P/ME) was near optimum--84.2, 79.6 and 75.4 mg kcal⁻¹ at 5, 25 and 40 ppt, respectively. Shrimp growth rate increased with increasing temperature over the range 24-32°C. There was significant interaction between effects of temperature and dietary protein level on shrimp growth. At 24°C, the diet with 16% protein and P/ME of 49.2 mg kcal⁻¹ provided as rapid growth as diets with higher protein levels. At 28°C and 32°C, the optimum protein level was estimated to be 25% with P/ME of 80.0 mg kcal⁻¹. L. vannamei is ammonotelic. Ammonia-N (TAN) accounted for 61.9-84.3% of total nitrogen (TN) excretion. Dissolved organic nitrogen (DON) accounted for 15.4-36.4% of TN excretion. TAN excretion rate (R[]) ranged from 6.38 to 23.26 []g-N g⁻¹ h⁻¹, and increased significantly with increasing temperature from 24 to 32°C. R[] was lower at 25 ppt than at 10 or 40 ppt. DON excretion rate (mean 5.24 []g-N g⁻¹ h⁻¹ ) was not significantly influenced by either temperature or salinity. In these static culture systems, TN accumulation increased linearly with feed-N input. TN accumulation was higher at 25°C than at 30°C, and at 45 ppt than at 25 ppt. Accordingly, N retention in shrimp was higher at 30°C than at 25°C, and at 25 ppt than at 45 ppt. N retention generally decreased with increasing protein level. Dietary protein level was the principal factor determining TAN levels in water. TAN accumulation increased dramatically, from 0.1-1.9% to 25.8-29.4% feed-Ns when dietary protein level increased from 16% to 34%. A simulation model representing shrimp growth and N dynamics in static culture systems was developed based upon N mass-balance. Simulated effects of temperature, salinity and protein/energy on shrimp growth and on TN and TAN accumulation generally agreed with observed values.
"Major Subject: Wildlife and Fisheries Sciences".
Issued also on microfiche from University Microfilm Inc.
Includes bibliographical references (leaves 167-190).