Author
HOUSTON, KEVIN - SC NATURAL RESOURCES | |
BRATVOLD, D - SC NATURAL RESOURCES | |
BRUCE, JEFF - SC NATURAL RESOURCES | |
KEGL, RYAN - SC NATURAL RESOURCES | |
Weirich, Charles | |
BROWDY, CRAIG - SC NATURAL RESOURCES |
Submitted to: Aquaculture America Conference
Publication Type: Abstract Only Publication Acceptance Date: 10/1/2002 Publication Date: 2/1/2003 Citation: Houston, K.R., Bratvold, D., Bruce, J., Kegl, R., Weirich, C.R., Browdy, C.L. 2003. Recent advances in larval culture technologies for Litopenaeus vannamei [abstract]. In: Aquaculture America Conference. p. 125. Interpretive Summary: Technical Abstract: Over the last decade advances in larval culture technologies for L. vannamei have been primarily driven by the private sector. However, inconsistencies in production and frequent dry outs continue to be the norm for most hatcheries and the scientific knowledge base regarding factors affecting larval health and fitness is limited. Although the use of probiotics to help control bacterial communities in hatcheries has increased, little empirical research has been conducted and most managers rely on poorly characterized formulations developed and maintained on site. Several commercial hatcheries have recently employed a two-stage larval rearing strategy in which N-5 larvae are raised through metamorphosis to postlarvae (PL-1), which are harvested and restocked and reared for eight to thirteen days (PL8-13) for shipment. This strategy allows for more efficient use of tank space and optimization of feeding strategies for planktonic larval stages and the more demersal PL stages. However, the two-stage larval rearing strategy has not been formally evaluated under controlled conditions. The present research was designed to explore the effects of water exchange, feeds and feeding strategies, and microbial community manipulation on system consistency, productivity, and target crop performance during the PL culture phase of hatchery production. Replicate 11-L microcosm systems were developed for testing growth and survival of PL (PL1 to PL 8-13) reared under different management strategies. Initial trials compared feeding of different artificial diets and Artemia establishing a standardized feeding regime using a commercially available #1 crumble fed four times a day with one feeding of Artemia/day. Additional experiments have explored effects of density (50 or 150PL/L) and daily water exchange rate (0, 50, or 100%) on water quality and postlarval performance. Results indicated that no significant differences with respect to growth and survival existed between water exchange rates at a stocking density of 50 PL/L. At 150 PL/L there were no significant differences in growth with water exchange, but there were significant differences in survival between the 0% and 100% daily water exchange treatments which were 77.8% and 84.1%, respectively (p=0.0481). The survival rates achieved suggest that it will be possible to rear L. vannamei successfully using two-stage larval rearing systems at high densities with low water exchange rates. Additional experiments will focus on use of increased stocking densities at minimal water exchange rates while maintaining production consistency through the evaluation of improved feeding regimes, the study of effects of habitat, and the use of probiotics and fertilization to manipulate microbial communities. |