Sexing juveniles T. cristatus

[del]

Is it possible to sex juveniles of this species with length of members rule ?

 

[Azhael]

The genus Triturus in general tends to mature fast in captivity, specially when raised aquatic, so it´s usually possible to see some differences between the sexes a short time after metamorphosis. However, it´s not always possible to accurately sex them if no secondary sexual characteristics have started to develop yet. I´d check for a dark cloaca. It´s an excellent way of telling males from females for certain. It could appear as early as a few weeks after metamorphosis, but can be delayed several months. The other secondary sexual characteristics, like longer digits, a crest and general coloration will develop shortly after the cloaca starts to darken, and make telling apart the sexes remarkably easy.

 

[del]

ok thx. Do you have a picture to illustrate the dark cloaca ?

And what about the anterior members length Versus Anterior-Posterior distance ?
I read if the L of anteriors is between 55-65% of the distance ant-post, the individual is a male. For 45-54%, it's a female.

Don't know if i was clear.

 

[Azhael]

Caudata Culture Species Entry - Crested Triturus species
There you can very clearly see the differences in cloacal coloration between males and females of the cristatus complex.
The proportions of various body parts may help to make an inference on the sex but i wouldn´t consider them accurate for juveniles. Like all the other stuff, body proportions will be affected by the onset of maturity and the changes it causes. In juveniles the differences in proportions may be small and deceiving.

 

[del]

Thanks a lot Azhael :happy:

 

[caleb]

This was investigated in T. macedonicus in this paper:
Cvetković ,D., Kalezić, M.L., & Džukić, G, 1997. Sexual size and shape difference in the crested newt (Triturus carnifex): ontogenetic growth aspects. Alytes 15:37-48.

They found that females grew faster, and had a lower Wolterstorff index than males (the difference increasing as they approached maturity). Tail fin height was also different (presumably bigger in males).

These differences mainly appeared after the first hibernation.

As Azhael said, dark cloaca is more likely to be useful for captive animals.