It is also likely that developing embryos are able to
absorb organic nutrients from the surrounding seawater. Indeed, there is often benefit
in adding a little cultured algal food
to tanks containing embryos 12 hours before they have reached the D-larva stage and are capable of ingesting particulate food. It may not
be the algal cells themselves that are important but rather organic nutrients in solution
in the algal cultures. In this respect, the addition of small quantities of diatoms (e.g.
Chaetoceros muelleri at 10 to 20 cells per μl) from cultures nearing the stationary phase
appears to be most effective.