Short article on the breeding ecology of <i>Cynops orientalis</i>

[ralf]

I don't know if its been mentioned on this forum before. A short article on the breeding ecology of Cynops orientalis can be found here: http://www.giant-salamander.com/view_en.asp?id=681

 

[jennifer]

Interesting. They can spawn for 65 days from a mating, while only 14 days for cyanurus. This kind of data is rare.

 

[wouter]

This article has been cited before on this site, I'm having some doubts about it. I've got the full version, and the data on C. cyanurus is just too detailed. I think that they looked at just a few C. cyanurus.
It could give some clearity on the difficult breeding of the Chemnitz cyanurus line on the other hand...

 

[edward]

Haven't checked the article out yet but in my experience about 1/3 of the cyanurus eggs I get are infertile.

Ed

 

[TJ]

Some extracts from this report can be found here:

http://www.caudata.org/forum/messages/13/14740.html

 

[ian]

the intended translation of the table is kind of accurate. But if anyone like me to retranslated that I can do so. Afterall, I am chinese. Reading those is extremely easy for me.

 

[ian]

translated anyway, enjoy.

The Fertility seems to represent how long the breeding season/period is. Literally, it means "The ability/capability of egg fertilization". But dont' know why it is in days or months. So I made such a guess.

 

[TJ]

That's very much appreciated, Ian!

A lot of the characters used in Chinese are not used in Japanese (including even the characters for "newt" and "salamander"), so I feared making an error in my translation.

I'd sure like to see a chart like this comparing all species of Cynops!

 

[edward]

Hmm,
At work the breeding period for the cyanurus is about 6 months, while my group at home is still laying eggs four months after begininng to lay eggs.

Ed

 

[ian]

Yea, that is why I am confused and dont know what that fertility row represents.
It seems a big difference b/w the two species at that particular item.

But how do you know the breeding period of Cyanurus is 6 months, just curious.

Maybe it means: if eggs are developed in the female, how long can the eggs stay unfertilized before laying.

If anyone need any translation of Chinese Caudata Article, just feel free to find me. But just dont ask me to translate a book.

(Message edited by achiinto on November 11, 2005)

 

[edward]

I would consider the reproductive period, to be the period in which egg production and deposition occurs as the females can be induced to ovulate either by manipulating temperatures or hormonal inducement.

I have had a breeding group at work for the last ten years and each year the females deposit eggs for about six months (this is slightly variable depending on the temps) as one year I was able to extend the reproductive period for 9 months by manipulating the temperature. The reproductive period can also be shortened by decreasing the caloric intake of the newts while increasing the temperature.



Ed

 

[ian]

interesting to know that. so the shorter the reproductive period suggest the smaller amount of population (eggs) ?

 

[joseph]

Does anyone have an explanation for the male biased sex ratio? It seems counterproductive to me if their are mor male than females. Perhaps they are sampling in the water only and many of the females stay on land for long periods?

Has anyone observed the sex ratios of newts in captivity?

 

[ian]

well. I have 1 male and 3 females with me. That is 3:1 . Not so bad, and they breed like crazy.

 

[edward]

Hi Ian,

1 male and three females is notated as 1.3.0 (Typical sexual notation for ratios has the male first, the females second, and unsexed third).

I have not seen a significant skewing towards males in the ones I have reared.

As for the number of eggs, this may at least be explained in part by the size of the animals as larger animals typically lay more eggs. (And cyanurus is larger than orientalis).

Ed