MATTHIAS VON WUTHENAU1, ARMANDO GARCÍA-ORTEGA2, ANA PUELLO-CRUZ2, CHRISTIAN SCHLECHTRIEM3, ULFERT FOCKEN4, KLAUS BECKER1
1University of Hohenheim, Aquaculture-systems and Animal Nutrition in the Tropics and Subtropics (480b), Germany
2CIAD (Research Center for Food and Development), Aquaculture and Environmental Management, Mazatlan, Mexico
3National Water Research Institute, Department of Aquatic Ecosystem Management, Canada
4University of Hohenheim, Animal Production in the Tropics and Subtropics, Germany
During the last decade global aquaculture production doubled and thus represents an important source of income and food. Due to the dependence of the early larval stages on live food, production of stocking material still represents a crucial bottleneck in the full commercialisation of many marine finfish and crustacean species. The free living soil nematode Panagrellus redivivus is well known to be an excellent food source for first feeding fish larvae. It represents an alternative to the highly expensive Artemia, which is commonly used. The lack of a proper method for mass production of P. redivivus has prevented its wider use in commercial hatcheries. A new cultivation method allows the production of a sufficient quantity of nematodes to deliver a standardised and permanent available live food of high quality, throughout the larval rearing period. This method consists of autoclavable plastic bags filled with sponges soaked with growing medium. The bags are inoculated with Saccharomyces cerevisiae, kept aerated and humid during the incubation time. Depending on the medium used, the nutritional characteristics of P. redivivus can be altered to a certain degree, to fit larval demands.
The experiments were carried out at the CIAD (Centro de Investigación en Alimentación y Desarrollo), Mexico. Several feeding regimes were established to prove the quality of the mass produced P. redivivus for larvae of Litopenaeus vannamei, the pacific white shrimp. Two different nematode treatments were compared to a no feed group and a control group which was fed with Artemia. All treatments had an additional algal co-feed and were run in five replicates. P. redivivus was cultured on two different media (wheat/corn flour and oat flour) to compare these for their suitability as high quality live food for the larvae. At the end of trial survival rate, body length, dry weight, developmental stage and protein content of the shrimp were evaluated. Shrimp fed nematodes grown on wheat/corn medium reached the post larval stage earlier than those from other treatments. The nematode treatments showed promising results which empasize further research on topics like different growing media or enrichment methods for essential fatty acids.
Keywords: Alternative live food, Litopenaeus vannamei, pacific white shrimp, Panagrellus redivivus