A new desiccation-tolerant and pathogen free live feed for shrimp and fish aquaculture  

The sustainability of the shrimp and fish aquaculture industry is threatened by the strong dependence of hatcheries on the live feed Artemia, with its production levels varying subject to seasonal weather and a resulting price volatility. The company e-nema (Germany) has developed a new dehydrated live feed that can be stored and rehydrated/reactivated on demand. The new pathogen free feed Panagrolaimus sp. is a nematode species which is mass produced in sterile conditions in bioreactors at constant yields with easily available land bound feedstock. It can be stored as long as the dormant eggs of Artemia; it is easy to use and performs better than inert diets. Reactivation is initiated by rehydrating the product in water for only 30 min at room temperature with no further need for specialized infrastructure or labour. This alternative live feed is one solution to satisfy the demand and to further stabilize the sustainability of this industry.

A feeding trial was carried out on white legs shrimp (Litopenaeus vannamei) postlarvae (PL) fed three dietary treatments for 10 days, from PL13 to PL22 in a recirculated aquaculture system (RAS): 1) Artemia and an artificial diet, 2) Nematodes and an artificial diet, and 3) artificial diet without live feed. In a second part, shrimp larvae were further cultivated 11 days on the artificial diet from PL23 to PL33.

Nematodes produced larval performances equal to those of Artemia at the end of the live feed period at PL23 (15.5 mm and 46.8 mg in average) and at PL33 (142.3 mg and 88.9% final survival, in average) (Table 1). Nematodes produced PL23 with a narrower spectrum of lengths than Artemia, which is better for economic reasons (Figure 1).

Shrimp fed on the artificial diet only were smaller at PL23 (11.9 mm, 26.0 mg) and at PL33 (114.0 mg), showing the benefit of live feeds.

For the first time a nematodes species mass produced in sterile conditions and stored desiccated was successfully reactivated as a live feed to replace 100% Artemia, during the nursery of shrimp PLs in RAS at precommercial level.