ABSTRACT
The oocyte maturation was triggered in vitro in far eastern sea cucumber by the addition of extract of radial nerves from sea stars in sea water. The embryonal and larval development including metamorphosis are described in Stichopus japonicus. In contrast to other echinoderms specific with katastrophic metamorphosis the metamorphosis of S. japonicus was reffered to evolutionary type as well as that other holothurians. The evolutionary type of metamorphosis currently with the lack of jelly coat and hyaline layer implies that holothurians might be considered as primitive echinoderms. For that reason it is undesirable to unite them with echinoids to the subphylum Echinozoa.
