<i>H. nigrescens</i> egg sac

[TJ]

This is the first time I've ever seen one of these up close and personal so it's a real treat. The egg sac of this species is very distinctive among Japanese hynobids -- the only one to be milky. I was surprised at its consistency -- very soft and gooey (unlike H.tokyoensis egg sacs, for instance, which are surprisingly firm). But when it's put back into water, it naturally tightens up again.

For more pics of eggs, larvae, juvies and adults, see:

http://www.rieo.net/amph/saramand/sansyouo/kurosan.htm

 

[uwe]

The milky color is interesting. Sometimes Ambystomides have also milky color. I think there was research done about what is causing it. Maybe Nate knows.

Uwe

 

[TJ]

Uwe, I was wondering just that, namely if any other species have similar egg sacs.

Here is a link to some information on the website of Dr. Masato Hasumi, who has studied H.nigrscens in some detail:

http://www5d.biglobe.ne.jp/~hasumi/photo/hn_e_e.html

He notes, "A spindle-shaped egg sac is characteristic of H. nigrescens, which is unknown in other hynobiid species."

Here, he shows a huge mass of egg sacs (more than 500 pairs) deposited in a small pond:

http://www5d.biglobe.ne.jp/~hasumi/photo/mixed_e.html

 

[TJ]

Here's a recently hatched larvae:

 

[TJ]

and here's a tail shot in focus:

 

[TJ]

The egg sac I took home with me was of questionable viability to begin with and has begun to deteriorate as expected. Poor shipping is probably to blame. But it does afford a chance to see the spherical shape of the eggs that've slipped from the egg mass:

I did make a point of bringing home an already hatched larvae just in case the egg sac didn't develop. It was hatched from another sac.

(same individual as in above pics)

 

[TJ]

These two beauties were being sold as H.nigrescens at a pet shop:

 

[TJ]

And here's my single larvae shown previously, but as of today: