Shrimp are sensitive to environmental changes and pond water quality. For example, they may not eat after a 50% water change.
Rare shrimp technology is a growing trend in the industry, with a handful of companies making major inroads into this segment. Janker cited Noray Seafood in Spain and CP Foods Homegrown in Germany as examples.
1. Temperature
Temperature is a key factor that affects shrimp growth and health. Shrimp grow and thrive well in a water temperature that is ideal for their metabolism and biological processes. However, sudden temperature changes can lead to poor molting, reduced appetite and decreased resistance to diseases. The best way to prevent these issues is by regularly monitoring the water temperature.
In experiments conducted by Kasetsart University in Thailand, scientists compared the performance of Pacific white shrimp (Litopenaeus vannamei) under two experimental temperatures to determine its effect on survival, feed conversion and growth rate. The results show that the feeding rate and gill slit opening of the shrimp are directly affected by water temperature. Moreover, the fry survival of the shrimp decreases as the water temperature increases. The feed conversion rate, on the other hand, increases with increasing water temperature.
Another important aspect of the water temperature is that it can affect the biochemical composition of the shrimp. In one experiment, the lipid concentration of the juvenile shrimp increased with a rise in temperature, while the protein and glycogen concentrations were similar between treatments. It is also important to note that the lipid concentration of the juvenile shrimp was higher at 24 degrees Celsius than at 28 and 32 degrees Celsius, which suggests that the growth trajectory and biochemical composition of the shrimp are affected by the temperature experienced during the early stages of development.
Farmers need to be aware that temperature fluctuations can cause the water quality of their shrimp ponds to decline rapidly, which reduces the ability of the shrimp to absorb nutrients and toxins from the feed. This can lead to a decline in the shrimp’s immunity and increase their susceptibility to diseases, which may ultimately result in high losses for farmers. To avoid this, farmers should regularly monitor the water temperature of their ponds and adjust their daily feed dose accordingly.
2. Water Salinity
The salinity of the water is an important factor that influences the health and growth of shrimp. Water salinity changes due to evaporation and precipitation. In addition, the salt content of the water can be decreased by adding freshwater from pond runoff or the emptying of rivers. The salt content of the water needs to be maintained at a level appropriate for shrimp to thrive. In order to do this, farmers use a hydrometer or a salinity meter regularly and adjust the water levels as needed.
The pH of the water is also critical for promoting the growth and health of shrimp. Fluctuations in pH can impact the ion balance and metabolic functions of the shrimp, and high levels of hydrogen sulfide or ammonia can inhibit their development and lead to diseases. It is therefore necessary to monitor and maintain a pH range of 7.0 – 8.5 for optimal shrimp health and growth.
Shrimp can adapt to a variety of salinity levels, and they grow best when the salinity is close to their isotonic point. This is why farmers often acclimate their shrimps to low salinity conditions after the post-larval stage, which helps them avoid wasting expensive natural sea salts.
However, it’s important to note that shrimps adapted to low salinity conditions may be susceptible to stress and have diminished immune systems. A recent study conducted by researchers at Khulna University compared the performance of shrimp reared in varying salinity treatments, including 0%0, 2.5%0, 5%0, 10%0, and 30%0. The results showed that the shrimps raised in 0%0 salinity had lower final weight, body weight gain, and specific growth rate than those reared at the other salinity treatments. The hemocyte counts of the experimental shrimps were also impacted by the different salinity treatments. Hemocyte numbers were higher at the control salinity (20%0) than all other salinity treatments.
3. Feeding Frequency
Feeding frequency is one of the main factors in feed management and its importance to shrimp growth and health cannot be overstated. It is crucial that farmers understand the optimum feeding frequency for their specific farm. Feed consumption depends on the nutrient density of the diet fed, water stability, palatability and feeding management strategies. Feed consumption also increases with increasing dissolved oxygen (DO) levels. However, DO declines during harvest which can cause stress in the shrimp. It is therefore important that feeding programs are adjusted based on weather conditions and water temperature.
In the case of pond-based farming systems, most farms usually feed their shrimp twice a day. However, studies have shown that apportioning the daily feed ration multiple times in 24 h improves feed conversion efficiency and water quality. Additionally, it prevents feed wastage and ensures the dietary protein is more evenly distributed to the shrimps.
Some researchers have even found that reducing feed consumption during the day and allowing the shrimps to eat at night helps them adapt better to adverse environmental conditions, such as changes in temperature or water salinity. This is because nocturnal feeding helps the shrimps reduce their stress levels and increase their tolerance to extreme environmental conditions.
Another important factor in feeding shrimp is the handling of the shrimps during feed preparation and harvest. Shrimp are naturally apprehensive to being handled and their response to this can be interpreted as a primary stressor, eliciting the same responses they would to predators or other stressful situations. For example, if shrimp are chased during feed preparation, they will interpret this as an aggressive act and may not reengage their feeding. Similarly, during harvest, if the feed is stopped suddenly, the shrimps will be frustrated and may attempt to burrow into the pond sediment in search of food.
4. Feeding Type
Shrimp are incredibly versatile creatures that can survive in both freshwater and marine environments. As with any species, the type of food they consume plays a major role in their health and well-being.
The most common way to feed shrimp is with a pellet designed specifically for them that has been formulated to contain all the nutrients they require in the right amounts. This is often referred to as a complete or balanced diet.
However, a number of other foods can also be used to supplement this. For example, canned or blanched vegetables can be fed to the shrimp to help increase the vegetable content of their diet. Green beans and sliced carrots are popular choices because they are nutritionally dense and easy for the shrimp to digest. Carrots are also a great source of beta-carotene which helps to enhance the red-orange coloration of the shrimp.
Another alternative is using a high-quality protein product, such as mussels or krill, to help ensure that the shrimp are getting enough protein in their diet. These can be fed to the shrimp once or twice per week.
Feeding shrimp a variety of foods is also important because it helps to keep the gut microbiota in good condition. This is a very important factor in the growth and health of shrimp, as the gut microbiota acts as a first line of defense against pathogens.
Lastly, it is very important to not overfeed the shrimp. Overfeeding can lead to a buildup of ammonia in the water which can stress or even kill the shrimp. Additionally, the leftover food can rot in the tank and pollute the water. To prevent this, adding a few snails to the tank can be beneficial as they will quickly eat any extra food that has been left over and reduce the amount of ammonia in the water.
5. Feeding Time
Providing your shrimp with a diet that mimics their natural environment will increase their health and well-being. The food they eat in nature contains various vitamins and minerals, and a balance of them will help the shrimp avoid diseases and molting issues. To achieve this, it is important to add a variety of food sources to the tank, including leaves like nettles and spinach, vegetables such as kuri squash or zucchini, and canned or blanched green beans.
It is also recommended to feed your shrimp during the day. This will make them eat more food than they would if they were fed during the night. The result of more feeding is a higher protein content in the shrimp, which will also contribute to their vigor and disease resistance.
However, you should be careful not to over-feed your shrimp. If you overfeed them, the extra protein may prevent them from undergoing normal molting cycles. The shrimp will not be able to absorb all of the calcium and other nutrients needed for a healthy molt.
Another factor that influences the palatability of the feed is the time when it is delivered to the tank. Feeds soaked for 30 or 60 minutes have a different amino acid composition than fresh feed, which can affect the overall ration of the shrimp. This is why it’s important to test the water conditions before determining the exact amount of feed that should be distributed to the tank.
It is recommended that you check the feeder tray after every feeding. This will allow you to see whether there are still pieces of un-eaten food left in the tray. The next feeding amount can then be reduced by 10%, assuming similar weather and conditions.