Development of Embryos in Egg Sacs 2

Egg Sacs 1Egg Sacs 2

Development of embryos in a pair of egg sacs, deposited in a breeding torrent of the salamander Hynobius kimurae, inhabiting Hokujo, Hakuba-mura, Nagano Prefecture, Japan.

(A) A pair of egg sacs, consisting of 22 embryos (3 of them were unfertilized) and 24 embryos (3 of them were unfertilized) at the early neural-fold stage (photographed on 4 May 2006). These egg sacs, the adhesive tips of which were attached to a small stone (7 x 5 x 3.5 cm), were discovered after the removal of a rock and decaying leaves accumulated in a place, 33.8 m upper from the 2005 oviposition site of the torrent (water temperature = 7.8 C, water pH-data = 6.1-7.2).

(B) Development of the embryos in the torrent (water temperature = 8.4 C, water pH = 6.9) after a couple of weeks (photographed on 20 May 2006). The embryos were at the mid tail-bud stage.

Accompanied Research Collaborators (alphabetical order): Iwao Hasegawa (Takefu, Fukui Prefecture), Masaichi Kakegawa (Tokyo Metropolitan Komatsugawa Senior High School), Fujio Kishi and Yuko Saikawa (Shirouma Association of Naturalists), and Koji Takada (Nagano Chausuyama Zoo).


Copyright 2006 Masato Hasumi, Dr. Sci. All rights reserved.
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