Aquaculture America 2024

February 18 - 21, 2024

San Antonio, Texas

THE EFFECTS OF LOW DISSOLVED OXYGEN IN GREENWATER SYSTEMS OF THE PACIFIC WHITE SHRIMP Litopenaeus vannamei?

 

C. San Andres*, A. Araujo, K. Nguyen, T. Corby, M.  Rhodes L. Roy ,  J. Garcia and D. Allen Davis

 

 School of Fisheries, Aquaculture and Aquatic Sciences,

 Auburn University,

Auburn, AL 36849

cfs0046@auburn.edu



Low dissolved oxygen concentrations are often considered  as a factor  have been widely studied in  influencing  the performance of Litopenaeus vannamei as a common concern  in aquaculture . Different studies with  dissolved oxygen as  a primarymain limiting factor,  have indicated this is a has revealed valuable outcomesas a stressor factor thatwhich can influence on growth, tail flip speed, immune response , metabolic rates, and gene expression, but  most  research hasve been  conducted  in  long period of hypoxia settings using  water mixed with gaseous nitrogen and sodium sulfite to preserve hypoxia level .  Hence, there is a However, there is a remaining gap  in our to understanding  of  its effect in  natural  diurnal  cycles  and its impacts under natural  production environments.  Therefore, the objective of  this study aimedwas to create low dissolved  oxygen  conditions in a green water system and its  effect on  survival rate, growth performance, apparent net prot ein retention,  and  metabolic enzymes in hemolymph. Additionally ,  tissues of gill and hepatopancreas  were  collected  to search for inflammatory gene expression . Two trials were conducted a t Claude Peteet Mariculture Center i n Gulf Shores, AL. The first trial consisted of t hree levels of air supply (Low= 0.25, medium =0.35, high= 0.7 cubic feet per second (cfs)).  It  was set up with 12 tanks (750L) stocked at 35 shrimp/m2  and initial weight  (1.99 ±  0.06g) maintaining an  equal flow rate. The second trial  consisted  of  two levels of aeration (Low = 0.25 and high= 0.7cfs) stocked at 30 shrimp/m 2 and initial weight (4.30 ± 0.24g) .  Feed inputs were estimated with expected growth of 2 g week-1  for  the first trial and 3 g week-1 for  the second trial . Results showed that  hypoxia environments were achieved in green water , constraining aeration levels (Figure 1). The levels of metabolic enzymes  of  the hemolymphhemolymph, such as Alanine  aminotransferase and Alkaline phosphatase, were not significantly different among treatments  in the first trial. Moreover, low  dissolved oxygen concentration  happened more frequently in higher biomass  conditions, resulting in  an increment 9 % of low dissolved oxygen occurrences in the second trial, affecting significantlysignificantly affecting survival (P=0.003) and growth (P=0.048).). Th erefore,  growth performance  is influenced by a reduction in density  because of dissolved oxygen concentrations . WHAT IS THE CONCLUSIONlow DO produces larger shrimp ?