Live food production in Japan: recent progress and future aspects

Techniques to culture rotifers at high-density (2000 to 20 000 ind./ml) hav e been developed by utilizing condensed phytoplankton products. Many public hatcheries in Japan have introduced automated systems for culturing and ha rvesting rotifers. Research has been conducted on the diagnosis of rotifer culture status and chemical treatment for reducing stress on rotifers. Pres ervation of the resting eggs of rotifers for an extended period or at low t emperature (4 degreesC) for a limited time has become possible. Thus, appro priately sized rotifers can be provided to fish larvae, according to fish s pecies and growth stage. Techniques to identify the genetic status of rotif er strains have yet to be developed. Practices for culturing copepods in Ja pan have also been summarized. (C) 2001 Published by Elsevier Science B.V.