Back to SOP Index

Daily Check List

Weekly Check List

Monthly Monitoring

Feed Requirements

Essential Nutrients

Additional Nutritional Factors

Feeding Regime

Water Quality Requirements

Water Quality Action and Reaction

Water Quality Management and Biofilter Maintenance

Post larval fitness parameters

Post Larva Acclimitation


Risk Management, Bio-security and HACCP Implementation


System Disinfection Procedures

Equipment Maintenance

Record Keeping and Report Templates


Variables to be used in health evaluation

Survival Rates

The survival rate is an estimate of the change in number of shrimp in a tank over a period of time. The validity of a survival rate value depends on the accuracy of the data. Mistakes may result from inappropriate counting techniques,human error or inexperience and variability in the counting method. Often the shrimp are miscounted when they are first added to the tank.

Mortality Rates

Mortality rate is the number of dead shrimp that are counted over a period of time. Daily, weekly and monthly counts of dead shrimp are used to show the trends in disease progression, transmission, response to treatment or other management manipulations. Survival rates are normally the opposite of mortality rates unless there is escapement, miscounting or theft.

Growth Rates

Growth rates are a good indicator of the health of the shrimp in the system. Growth rates are influenced by environmental, genetic,biological and nutritional factors. For the first month of grow-out percentage increase in body weight are used to measure growth rates. By the sixth week weekly weight gains are estimated to determine the growth rates. From here on in growth rates can vary from 0 - 2.5 grams per week.At this stage growth rates of less than 0.5 grams per week are considered to be poor rates of growth and indicative of some sort of culture problem.

Size Variation

Some diseases or health problems can be identified by looking at the size distribution of shrimp in the tank.This does not need to be determined unless you see there is a problem with growth rates or mortality.

Feed Conversion Ratio

The feed conversion ratio (FCR) is a measure of the efficiency of feed utilization by shrimp. FCR values, together with other information, can be used to understand a problem with a production run. In general, the lower the FCR, the more efficient the feed utilization. Poor feed quality can reduce growth and increase FCR.

Appearance of Shrimp

Shrimp should be visually examined on a daily basis for changes in behaviour and colour (Form 1) . In order to identify problems, you must first be able to recognize normal appearance and behaviour of cultured L. vannamei. Unusual behaviour (i.e., lethargy, disorientation) can be indications of a disease problem. Changes in appearance, texture and colour of organs (i.e., gills,appendages,cuticle,abdominal muscle) should also be noted. Stomach fullness should be evaluated.



Health evaluation tests
Wet Mount Procedure . PL visual examination . Stress test for post larva . Gill examination . Mid-gut Examination . Stomach Contents Analysis

Shrimp Diseases
Hepatopancreatic parvo-like virus (HPV) . Reo-like virus (REO) . Lymphoid organ vacuolization virus (LOVV) . Taura Syndrome Virus (TSV) . Rhabdovirus of Penaeid Shrimp (RPS) . White Spot Syndrome Virus (WSSV) . Infectious hypodermal and hematopoietic virus (IHHNV) . Baculovirus penaei (BP)
Bacterial Diseases
Vibriosis . Epicommensal fouling disease (filementous bacteria) . Necrotizing Hepatopancreatitis (NHP) . Black spot disease (BSD) . Mycobacteriosis
Fungal Diseases
Larval mycosis . Fusariosis
Haplosporidia . Gregarines . Cotton Disease
Black Gill Disease (BGD) Dissolved Oxygen Crisis Nitrogen Gas Bubble Disease

Disease control
Decreasing density, partial or early harvests . Drugs, chemicals and treatments . Sanitation