For studies of the normal development of medaka (Oryzias latipes), the staging series by Matsui (1949) and Yamamoto (1975) have been used for many years. However, the staging by these authors is rather rough, especially in later stages of embryonic development. The illustrations of embryos in each stage are not so precise in detail that they can not reflect knowledge obtained by current research. A new staging series, describing more precisely and based on the latest knowledge, has been eagerly desired among researchers using medaka. Recently, a new staging series of the medaka development, "Stages of normal development in the medaka Oryzias latipes", was published by Iwamatsu (1994). This staging series is based not only on observations of external morphology, but also on histological observations of tissues and organs by the author and his colleagues. The illustrations are scientifically precise and rich in artistry. This staging series was first published in "The Biology of the Medaka" (in Japanese, 1993; see the book review by Ozato, 1993) and its English version was reprinted in The Zoological Science (1994) for international readers. Here, the staging series is printed in reduced size (Figs. 1 and 2) by courtesy of the author and publisher (The Zoological Society of Japan). For figure legends, refer to the original paper.
References
Iwamatsu, T. (1993) The Biology of the Medaka, 324 pp., Scientist Co., Tokyo
(in Japanese).
Iwamatsu, T. (1994) Zool. Sci., 11: 825-839.
Matsui, K. (1994) Jap. J. Exp. Morph., 5: 33-42 (in Japanese).
Ozato, K. (1993) Fish Biol. J. MEDAKA, 5: 41- 44.
Yamamoto, T. (1975) In ÒMedaka (Killifish): Biology and StrainsÓ (T. Yamamoto, ed.), pp. 30Ð59, Keigaku Publ. Co., Tokyo.
Fig. 1
Fig. 2