N Crocatus

[Michael]

I was reading the article on this species on Caudata Culture (which looks to have been written 10 years ago) and I came across this text.

"During the development to adulthood, there are often major problems at a certain point in development. Shortly before reaching sexual maturity, the subadults suddenly become very weak, get sick, and usually 100% of them die in a few weeks. The cause for this is unclear. It is possible that in this phase, a hormonal change in the total physiology of the animals is accompanied by a temporary immune weakness. The Aeromonas infections that have been diagnosed in these cases were caused by germs that ordinarily wouldn’t harm the animals. Macroscopic symptoms on the dead animals, if visible at all, are slightly bloodshot spots on the undersides of the feet. The animals will usually be found dead in the setup without any externally-recognizable cause. It is usually too late to initiate treatment for the remaining animals. The infections have not been known to spread to other salamanders.

In this way, the author has twice lost his complete batch of offspring of N. crocatus (8 and/or 14 animals). On a third occasion, the animals were isolated from one another at the first signs of this illness and kept for several weeks on paper towels soaked with a wide spectrum antibiotic solution, changed every three days. For 4 of the 6 animals, the aid came too late, but 2 survived under these conditions, showing no further symptoms and reaching adulthood without problems.

Because this phenomenon happened in a similar manner to a number of keepers under somewhat different conditions, this seems to be a specific characteristic of N. crocatus. Up to now, most captive bred offspring have fallen victim. In the future, special attention will be dedicated to this problem!

The studbook of Neurergus crocatus currently contains less than 30 animals, which live in various small groups with several European keepers. There were no more breedings or offspring in 2001 or 2002. Therefore, it will take the good will of all keepers of this species to bring together enough animals for viable breeding units and, in a joint effort, prevent this species from becoming extinct in captivity."

Is the development to adulthood still so unlikely? I find it amazing how this species is still in existence if this applies to them all. None of the other genus members has any similar issues to my recollection.

Any information on raising of juveniles to adults would be greatly appreciated.

[Jennewt]

Originally Posted by Revan

Is the development to adulthood still so unlikely? I find it amazing how this species is still in existence if this applies to them all. None of the other genus members has any similar issues to my recollection.

Any information on raising of juveniles to adults would be greatly appreciated.

When you say "still in existence", do you mean in existence in captivity, or in the wild? The bloodline(s) of crocatus that existed when that sheet was written are mostly gone from captivity. There has been a recent infusion of wild-caught animals, and it appears that the offspring (which have been sold around the world) are doing OK. Time will tell. My expectation is that they will do just as well as the other Neurergus being captive bred and should be raised under similar conditions.

[Michael]

Originally Posted by Jennewt

When you say "still in existence", do you mean in existence in captivity, or in the wild? The bloodline(s) of crocatus that existed when that sheet was written are mostly gone from captivity. There has been a recent infusion of wild-caught animals, and it appears that the offspring (which have been sold around the world) are doing OK. Time will tell. My expectation is that they will do just as well as the other Neurergus being captive bred and should be raised under similar conditions.

Apologies I should have been more clear, I was referring to the single import back in 1990.(RADSPIELER)

From what I have read (please correct me if i'm wrong) Crocatus should be matured in a terrestrial environment for the first few years, whereas Kaiseri and Strauchii can be kept aquatically.

Thank you for the information Jen.

[erik3333]

From what I heard - and I am by no means an expert - the 90'- import animals were carrying some kind of parasite.

[Markus1]

Hi.

I keep all kinds Neurergus also N. crocatus. I have 11 adult and 10 subadult animals. I have the subadult bred even and lost a pet until now. Next year they are adult. There are many people in Germany they have N. crocatus in the moment.

[Michael]

Thank you for the information. Could i ask what water temps you keep N Crocatus at? I have found out that average water temps for this species is between 10-18C, and 22+ could prove fatal. Is this correct from experience with this species?

[Markus1]

Hi.

I have a water temperature from 9-20°C. I think if the temperature is higher the animals leave the water.

[Sergé Bogaerts]

Markus is right, and above 22 degrees is not fatal, but makes the animals probably(!) more vulnerable to infectious diseases.

I still have descendants from the 90's import and they reproduce very year. However, it seems that Neurergus (for sure strauchii and crocatus, but probably the others too) can have pretty dramatic die offs within a short time frame. Besides relatively known candidates as ranavirus, there is also a newly one discovered, a bacterium: Candidatus Amphibiichlamydia salamandrae (Martel et al., 2012). The disease presents as anorexia, lethargy, edema, markedly abnormal gait and death.

These infections are probably (!) widely spread in urodelan collections and clinical signs are possibly provoked by suboptimal conditions, for example elevated temperatures during summer months or mal nutrition.

[Rodrigo]

That description of symptoms is extremely familiar to me....I have to check that out.