Effects of dietary protein:energy ratio and phosphorus level on growth and survival of Penaeus vannamei postlarvae and on aquacultural water quality /
A static-water ecoassay was developed with postlarvae (PL) of
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1996.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=739668051&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | A static-water ecoassay was developed with postlarvae (PL) of Penaeus vannamei to quantify the chemical impact of unassimilated nutrients and metabolic wastes on water quality in shrimp mariculture. Increased feed associated with increased stocking density and production rate increased nutrient loading in the water column. From these results, appropriate PL stocking density and feed rate were determined to evaluate various feed formulations and feed management strategies. PL survival ranging from 86.7 to 100% and growth ranging from 28 to 29%/day were obtained with this static system. Dietary phosphorus levels of 0.4% (NaH2PO4 supplementation) and 0.8% (CaHPO4 supplementation) provided good PL survival and growth, yet caused minimum dissolved reactive phosphorus (DRP) accumulation in the water. Diets containing Na2HP04and NaH2PO4 supplementation (0.8% dietary phosphorus level) had similar DRP accumulation. A net phosphorus utilization of 65.1% was achieved at a 0.4% dietary phosphorus level. A dietary protein:energy ratio of 41-50 mg/kcal (crude protein level of 18%) provided as good PL survival and growth as higher crude protein:energy ratios, yet caused lower dissolved total inorganic nitrogen (TIN) accumulation in the water. PL growth, but not survival, was reduced with diets containing 10% crude protein. Net nitrogen utilization ranged from 37.0% with a dietary protein level of 33%, to 85.5% with dietary protein level of 10%. TIN accumulation in the water increased with increasing level of dietary protein. TIN accumulation was almost negligible with the 10% dietary protein level. Feed stability decreased with increased dietary crude lipid level. Accumulation of settleable solids decreased and DRP increased with higher dietary lipid levels. The static culture system also had a growth-enhancing effect on postlarvae. PL growth was 42 to 46% more with the static culture system than with a recirculating culture system where water volume exchange was 133%/hour. Survival was similar or increased with the static culture system compared to the recirculating system. |
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| Item Description: | Vita. "Major Subject: Wildlife and Fisheries Sciences". |
| Physical Description: | xiv, 102 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 89-98. |