A wide variety of live foods are used for the different larval stages, such as Artemia nauplii and Moina. Up to stage V and VI the larvae have a poorly developed alimentary system (Deru, 1990) and cannot digest artificial diets. First feeding is therefore dependent on live food, which is highly digestible and may provide exogenous enzymes (Jones et al., 1993). From stage VII onwards the larvae become more omnivorous (Barros and Valenti, 1997) and artificial feeds can be used. At first feeding (Stage II/III) prawn larvae can readily ingest newly hatched Artemia nauplii (± 500 μm). However, Moina micrura (± 600 μm), which may be used as a cheap substitute or supplement for brine shrimp, is not ingested before stage IV (Alam, Ang and Begum, 1995). Rotifers (Brachionus plicatilis, ± 150 μm) are too small and not considered a suitable starter feed for M. rosenbergii (Lovette and Felder, 1988).  Feeding schedules for the different larval stages of M. rosenbergii and relevant references are provided in Table 3.

Zooplankton, insect larvae and oligochaete worms play an important role in the nutrition of freshwater prawns in ponds. Juveniles larger than 2 g feed on zooplankton. Hence, enhancement of macro-invertebrate production in ponds is extremely important in the production of freshwater prawns (Mitra et al., 2005). However, more uniform production of large prawns is achieved when commercial pellets or well formulated farm-made feeds are used.

The types of feed used in freshwater prawn farming vary widely and include ‘farm-made feeds’ and specifically formulated commercial pellets. Some farmers use commercial marine shrimp pellets in M. rosenbergii nurseries or during the first few weeks of the grow-out phase. Catfish feeds can also be use for grow-out of freshwater prawns. Commercial feeds may be the most productive and reliable to use but they are expensive, are not always available to the small farmer, and do not take advantage of locally available ingredients (Table 3).

A wide range of agricultural by-products of plant and animal origin can be included in prawn feeds. The composition of some commonly used ingredients is shown in Table 4. The level of inclusion of individual ingredients is dependent upon factors such as the presence of anti-nutritional factors, cost, digestibility and nutrient composition. Inclusion levels of some ingredients and their composition is given in Table 5. There is ongoing research for new and cheap ingredients, with a particular focus on plant based ingredients (Tiwari and Sahu, 1999).

No fixed feed formulation is available for M. rosenbergii. Generally, attention is given to include locally available ingredients to reduce costs. Commercial formulations generally do not reveal the formulation as a protective business strategy, although the type of ingredients used and the proximate composition is usually displayed. Four types of feeds, viz. pre-starter, starter, grower and finisher are available in the market. A formulation of an experimental feed is presented in Tables 5 and 7.  Egg custard is sometimes used as a replacement for Artemia (see Table 6 for composition of egg custard). Some ideal feed formulations for prawns are given in Table 8, 9 and 10.

Feeding schedules depend on the type of culture practice. Larval feeding schedules are almost uniform (see Table 3). Initially Artemia is fed for 7 days followed by a combination of Artemia and egg custard. Due to recent advances in nutritional research some micro-particulate/ microencapsulated/ microbound diets are used in place of the more traditional feeds. However, these diets are not 100 percent effective in replacing Artemia. Commercial feeds are used for post larvae. Considering their nocturnal feeding habit, about 60 percent of the total daily ration is fed at night in two installments, while the remainder is fed to the prawns once during the day. For the first month post larvae are fed at 6-7 percent of body mass per day, where after the daily ration is reduced to 4 percent. After two months the feeding rate is fixed around 2-2.5 percent per day. Feed intake is dependent on water temperature and the ratio is adjusted based on daily observations of feeding intensity in feed trays. This practice is commonly used in modified extensive culture systems, which is the most widely used farming system by farmers.

Prawns are slow feeders and hence water stability of the feed should be given utmost priority. Pellet water stability of two hours is considered to be ideal for prawns. Plant based feed ingredients are rich in starch, which are gelatinized when exposed to high temperature and pressure during extrusion. A significantly higher degree of water stability has been recorded for extruded pellet than steam cooked pellets. Lower feed conversion ratios and improved water quality have also been recorded with the use of extruded pellets (Sahu, Jain and Misra, 2002).  Some natural and or synthetic binders are also used to enhance water stability.