Color Changes in Ovary (Hasumi)

Color Changes in Ovary

Changes in ovaries and oviducts in female Hynobius nigrescens (Hasumi, 1996); fb = fat body, os = ovisac (uterus), ov = ovary, pc = pars convoluta of oviduct, pr = pars recta of oviduct. Scale = 1 cm.

(A) Late September: the deposition of melanin pigment is initiated peripheral to the ovarian eggs (vitellogenic follicles), which were colored mint green during late August.

(B) Late October: the ovarian eggs have a dark-brown surface after completing melanin deposition, but in their inside the vegetal pole in each egg still remains a mint-green color. At this time, oviducts and ovisacs develop markedly coinciding with plasma estradiol-17 beta concentration (Hasumi et al., 1993).

Footnote (24 October 2016): The term "ovisac" is confused with "egg sac". Although McDowell and Shinozaki (2015) cited it as "deposited ovisacs (Hasumi, 2001)", there is no description about such a term (i.e., deposited ovisacs) in Hasumi (2001), and ovisacs are not physically deposited outside.

McDowell, W. T., and N. Shinozaki. 2015. A synopsis and larval description of Hynobius kimurae Dunn 1923 (Caudata: Hynobiidae). Bulletin of the Chicago Herpetological Society 50: 13-18.