<i>Hynobius kimurae</i> eggs

[TJ]

(Message edited by TJ on April 18, 2005)

 

[TJ]

Here they are as they were found (after removal of the rock they were under, of course). The eggs are attached to a pebble.

 

[TJ]

The embryos in one of the twin sacs are mostly developing but those in the other sac are not doing so well.

 

[TJ]

Another year, another egg sac:

(Message edited by TJ on April 18, 2005)

 

[jennifer]

He says "another year, another egg sac" so casual like. Remarkable! Did you switch that topmost photo in the thread?

 

[TJ]

Well, I sure wish a could take another shot like that topmost photo. Try as I might, I can't replicate that one (which was taken in the mountains). Must have been a fluke

I'd vowed not to try again with this species, but then last week a friend of mine sent me a sac anyway.

Truth be told...I failed to raise that stunning set of sacs in the first pic. I'd had them tucked coolly away in the vegetable compartment of my fridge while I was away for a week. The embryos had developed to a point but then some went bad and then the others gradually did so too. I diagnosed oxygen deprivation, but who knows what went wrong. Had I known then what I know now, I would have performed a minor surgical operation to remove the bad embryos from the sac before they affected the good ones.

This species lays eggs under boulders in steep, narrow, and rocky streams with cold water. Coolness is evidently an important factor. But to what extent water flow is also important, I just don't know. There's not much knowledge available about raising this species from eggs, even here in Japan, so some trial and error is entailed.

I'm now keeping this sac in cool, aerated and cycled water. If I had a pair of sacs (one female lays two sacs, by the way), I'd try keeping the other sac in mineral water. With three sacs, I suppose I'd lower the temperature even further and add some flow. I'll limit myself to two sacs per season until I get it right

 

[pin-pin]

Tim, the egg photos are seriously sexy. Did I mention how much I enjoy your photos?

Oh wait, yes many times.

You never cease to amaze me.

So...how about some Taricha photos? *cough*

 

[pamela]

Nice Tim! Again, nature at work - so beautiful. The little ones look like teeny weeny belugas!

 

[TJ]

Thanks a lot!

Pin-pin, "sexy" is indeed the operative word here

I'll try to getcha some Taricha soon...

Pamela, they're now actively moving in the sac. But the sac is not all that transparent so it's hard to capture the embryos. Here's the best I could do this evening:

 

[TJ]

 

[pamela]

That is just soooo fantastic! Truly a wonder. Thanks Tim.

 

[henk]

Ouchhh you really hurt me here Tim

 

[frank]

Hi Tim, really amazing pictures. The following is not really my idea (it is Sergé Bogaerts'): you have put such an amazing variety of adults, eggs, larvae, juveniles and habitats of Japanese urodelans on this site. Why not compile this on a separate and permanent link? It would be an incredible guide...

 

[TJ]

Thanks a lot, Frank ... and Serg

Yes, well I'd very much like to do something in a more organized manner, preferably with the complete freedom to alter, refine content.

Jen has in the past suggested Caudate Central as a possible venue for something, so that's one nice option I've been considering. The other is to have my own website on Japanese newts and salamanders, This may become a reality as my brother will visiting from the States next week with the necessary software and with the HTML know-how that I sorely lack. I've held the domain www.cynops.jp for over a year now without doing anything with it

I'd been fantasizing about embarking on a 10-year project for a book...until I heard that some eminent Japanese herpetologists are already working on one that would be authoritative. Well, the idea isn't dead and buried --just in a state of suspended animation...

(Message edited by TJ on April 25, 2005)

 

[TJ]

Here's an update:

 

[pamela]

My, how they've grown! They can recognize each other now ;D Looks like they are talkin' about getting ready for the "big swim".

 

[TJ]

Well, I got 5-6 hatchlings out of this sac. Not a great yield. Some of the embryos had gone bad so I opted to intervene to save the rest by prematurely releasing them from the sac, though they'd already begun moving around inside it at the time.

 

[henk]

That's also whatr I do when the sac start to go defenitely bad Tim. Just did that now with my tokyoensis. BTW Those lichenatus are really fast growers

 

[TJ]

Lichenatus? You mean the ones you're raising now?

I forgot to mention that the size of that H. kimurae pictured above is now 3.5 cm, or a gain of 1 cm in less than two weeks.

This is what Goris has to say about H. kimurae egg sacs and eggs:

"The pair of egg sacs are long and straight, with the free tip (i.e., the end not attached to the rock) bent back sharply in a hook. This part contains no eggs. The gelatinous sac has a purplish sheen and is very tough and not easily torn. The number of eggs is not great, a total clutch consisting of 13-51 eggs. After hatching, the larvae may remain for some days or weeks inside the tough sac, emerging at the end of May to the middle of June."

Source: Guide to Amphibians and Reptiles of Japan, by Richard C. Goris and Norio Maeda, 2004

I can testify to the toughness of the egg sacs of this species. They're really quite incredible, even tougher than that of H. tokyonensis.