Early mortality syndrome causes high mortality of shrimp in their juvenile stages. The affected shrimp die from hepatopancreas dysfunction and secondary infections. This course describes the Vibrio bacteria that cause EMS and how their increasing density produces a damaging toxin. There is no “cure” for EMS, but the use of EMS-free postlarvae and efforts to minimize the accumulation of organic matter can limit its presence and impacts.
Early mortality syndrome (EMS) is a serious disease that causes hepatopancreas dysfunction and up to 100 percent mortality in farmed shrimp. Students will learn the bacterial cause of EMS and that virulence depends on infection route, exposure time and general shrimp condition. The most effective practices for controlling EMS at hatcheries are sourcing disease-free broodstock, avoiding live feeds, limiting organic loads in rearing tanks and regular system disinfection.
Enterocytozoon hepatopenaei is a tiny parasite that disrupts shrimp digestive systems. The animals’ reduced feeding results in slow growth and wide size variation. This course describes how to identify EHP and recommends practices to exclude the pathogen through biosecurity measures. Impacts at affected facilities can be minimized through careful pond preparation, stocking with high-quality postlarvae and pond management that avoids overfeeding and accumulation of sludge.
Enterocytozoon hepatopenaei is a tiny parasite that disrupts shrimp digestive systems. Its presence reduces feeding and results in slow growth. In addition to learning the symptoms of EHP and the best testing methods, students will learn the most effective control is exclusion through strict biosecurity. If a hatchery is affected, it should be aggressively disinfected, with additional biosecurity measures taken to limit EHP spore loads and potential reintroduction.