3RD INTERNATIONAL CONGRESS ON TECHNOLOGY - ENGINEERING & SCIENCE - Kuala Lumpur - Malaysia (2017-02-09)

Influence Of Ammonia Concentration On Incidence Of Early Mortality Syndrome In Shrimp Culture
The shrimp disease known as Early Mortality Syndrome (EMS) has caused devastating losses in shrimp hatcheries in Mexico and other countries [1,2]. It is caused by Vibrio parahaemolyticus, a bacteria which destroy hepatopancreatic tissue of infected shrimps, causing a fast death. Several authors have reported that high ammonia concentrations in water of cultured shrimp depress immune system of shrimp, consequently might increase virulence this bacteria [3]; so the aim this work was correlate EMS incidence´s vs. ammonia concentrations. Groups of 5 flasks with seawater 30 (ppm), and 10 PL-15 shrimp per flask were reared as following: Series S, flasks with seawater and shrimp. Series SB, flasks with seawater, shrimp and Biofilm (a microbial community conformed by microalgae, heterotrophic bacteria, dinoflagellates, protozoa and other planktonic microorganisms). Series E, flasks with seawater and shrimp infected with Vibrio parahaemolyticus. Series EN, flasks with seawater, shrimp, NH4Cl solution to increase ammonia concentration, and infected with Vibrio parahaemolyticus. Series were set outdoor during 5-6 days, constant aeration was supplied to flasks, shrimps were feed two times per day, and ammonia concentration and shrimp mortality were recorded daily. Results shown that ammonia concentration, increased like an exponential way during experimental time (Fig.1). As can see, higher concentrations were recorded in Series EN, and lower in Series SB; also, shrimp mortality was directly correlated to ammonia concentration; i.e., the higher mortality was recorded in Series EN and lower in Series SB (Fig. 2). The experiments, ammonia concentration analysis and mortality records were realized by triplicate, and data obtained were statistically process by ANOVA one via, using Stat-Analysis software. This results, corroborate the hypothesis of this work, consequently can be conclude that Biofilm improve shrimp immunity, reducing virulence of Vibrio parahaemolyticus, and consequently the mortality. Also, nitrifying bacteria contained in Biofilm, improve water quality lowering ammonia concentrations from culture system through nitrification process.
Guillermo Galindo Reyes