behavior of the larvae of individual classes, based on published and original 

 material. Larvae are examined not so much from an embryological point of 

 view (as a developmental stage of a definitive animal), but from a zoological 

 viewpoint (as an organism endowed with all the systems required for a viable 

 existence in the plankton). The general description of the larvae studied begins 

 with a brief report on early development (up to the stage of trochophore or 

 dipleurula). Cytoembryological aspects of early development are not described 

 because extensive literature is available on this topic. The description con- 

 cludes with a summary of the process of metamorphosis and a brief charac- 

 terization of lecithotrophic larvae. Ecological aspects of the pelagic life of 

 larvae and their settling to the bottom are not described due to space con- 

 straints of this book. 



Plankton samples were collected mainly in Vostok Bay, which is situated 

 in the eastern part of Peter the Great Bay of the Sea of Japan. To obtain the 

 required stage of larval development, artificial fertilization with subsequent 

 culturing of larvae was done, in addition to selection of larvae from plankton 

 samples and subsequent culturing. This work was carried out under the guid- 

 ance of V.L. Kasyanov, assisted by S.Sh. Dautov, who described the larvae of 

 the sea star Asterias amurensis and compiled Table 5 (Types of Development 

 of Sea Stars). 



The authors are grateful to V.A. Sveshnikov, the editor-in-chief of this 

 volume, to V.V. Malakhov and V.G. Chavtur for excellent advice, and to O.M. 

 Kom, T.I. Ponurovskaya, T.N. Chemenko, and the staff in the photographic 

 laboratoiy of the Institute of Marine Biology who assisted in manuscript prepa- 

 ration. We thank the corresponding member of the Academy of Sciences, 

 USSR, A.V. Zhirmunskii, the entire staff of the Laboratory of Embryology, 

 Mrs. Irina Barsegova and Mrs. Tatiana Kotnova for their support during this 

 endeavor. Collection of material and its analysis was partially financed by 

 TINRO MRKh* of the USSR. The authors are grateftil to Mr. Gulab Primlani 

 and Oxonian Press for translating their book into English. 



In the new edition we have introduced corrections and additions. The list 

 of species described in the book has been enlarged, new illustrations have been 

 added, and species sections have been rewritten. It is hoped that through this 

 English language edition the book will reach a new circle of readers. 



V. Kasyanov 



* Pacific Scientific Research Institute of Fisheries and Oceanography, Ministry of Fisheries — 

 General Editor. 



