Laotriton question

[wildperu]

Dear all,

I have two pairs of these newts and they are strong and sturdy, eating everything in sight: Dillies, and reptomin, live black worms and even some live Daphnia, oh and the occasional Phoenix worm thrown in as a treat.
They are housed in a 30 long together; mostly water with a flat bricks stacked up for caves and a place to crawl out on. Very little plant material and a gravel substrate. The water they are in is treated tap with a little rain water mixed in: pH is 7.5, gH is 120 ppm, Nitrates and Nitrite are zero with two 90% water changes per week. I figured they would appreciate that level of cleanliness since their diet is pretty protein rich. The temperature says steady at 19-21C, not varying much from that range.

My question concerns stimulating them to spawn. From my reading here it seems to require cooling them off a bit- down to 16C or so, with cool water changes helping also. Are you all maintaining them at this lower temperature. (16) year round, and then cooling them further with the water changes? Or are you maintaining them at some higher temperature (like I have them now) during the "off season" and dropping the temps to 16 only when you are preparing them for spawning?

I will now go back to lurking mode and enjoy reading your responses

Thanks,
Brian Perkins

[FrogEyes]

16C isn't especially cool. Mine were down to -4C, under ice, before bringing them indoors, but I think it's too warm indoors. Justin reported a male encased in ice before coming into color. A local friend has at least one coloring up right now, but I don't know how cool his basement is. My suspicion is that a good hard chill is very helpful, and a continuing temperature closer to 12C might work well. I'd have to dig back through a variety of threads and references to see what actual data are available. I think the shortage of previous successes with this species has been largely due to "cool" temperatures being just too warm. While this species is from central Laos, all of its relatives and ancestors came from colder and more northerly places. Odds are that their natural creeks get colder at times than people think, and if not, they've still inherited a tolerance of and stimulation by cold water.

[Michael Shrom]

Some of mine are at room temperature in my living room and laying eggs like crazy. The male was in the basement for the summer but it didn't get much below 68F.

[Coastal Groovin]

This should give you guys some insight into the temps you should drop them. Just look up the weather!!!!

The dry season from November to March, which has low rainfall and temperatures as low as 15°C (or even to zero in the mountains at night), No matter where you are it always gets cold in the mountains at night.

[wildperu]

Thanks for the replies. "Encased in Ice"?? wow! Here in Houston it can get fairly cool, but not for extended times. It's very variable. And Michael, yours didn't get less than 68F since you;'ve had them and they are "laying eggs like crazy", hmmmm! OK, I think a little more research and experimentation are in order it sounds like!

Thanks,
Brian Perkins

[wildperu]

Great sig. line, btw! :O)

[FrogEyes]

I agree, but the mountains this species occurs in are not the towering bare peaks of the Rockies or Himalaya, but short forest-covered hills close to the equator.

On the other hand, we know experimentally that this species is quite cold-tolerant, and freezing temperatures do seem to stimulate reproduction [even if not necessary to do so].

[Coastal Groovin]

Ok is this better? The weather for tomorrow is a low of 4.4C (40F) and 20.7C (69F) at the Xiangkhouang Province airport......lol. They may be found in other colder areas of the country that scientist have not explored or already be expirated from these areas due to the food trade. This could explain their wide tolerance for different temps people have found. Just a guess.

[Henry Janssen]

Hello Brian,

Based, not on wild guesses or on what others said or wrote, but on the carefull evaluation of detailed notes I made during 5 breeding seasons of the two adult pairs of Laotriton laoensis that I keep, I come to the conclusion that these newts start breeding when, in the late fall or early winter, the water temperature reaches between 19°C and 20°C after a slow and steady decline from 24°C in summer.

All you have to do is keeping the water temperature constantly between 19°C and 20°C for the duration of the breeding season. Slight rises ( to 21°C) or slight drops ( to 17-18°C) of the water temperature often results in the females stopping oviposition after a few days, but they restart when the 19°C temperature is restored.

A partial water-change enhances the stimulation to spawn, but make sure you use water with exact the same temperature as the tankwater and avoid disturbing the animals.

Any major distubance like cleaning the tank, changing the set up of the tank or sudden changes in water temperature at the start of, or during the breeding season may result in the breaking off, or not even starting the breeding for that season.

The temperatures you have right now are near perfect. Don't lett yourself talk into drastic drops of water temperature. This is common practice in Europ and I am convinced that this contributes to a large degree to the poor breeding results with this specie so far.

Michael has got it right. Keeping Laotriton,who are very sensitive to even the slightest change in water-temperature at freezing temperatures, like Frogeyes does, does not only not correspond with their natural needs but is, in my book, nothing short of crualty.

Henry

[Justin]

Originally Posted by Henry Janssen

Based, not on wild guesses or on what others said or wrote, but on the carefull evaluation of detailed notes I made during 5 breeding seasons of the two adult pairs of Laotriton laoensis that I keep, I come to the conclusion that these newts start breeding when, in the late fall or early winter, the water temperature reaches between 19°C and 20°C after a slow and steady decline from 24°C in summer.

So the original poster is just supposed to disregard everyone else's success because you have detailed notes on two pairs? Mine are kept at a temperature range of 23'c during the summer to 1'c during the winter. They didn't start laying until the water hit 11'c.

The temperatures you have right now are near perfect. Don't lett yourself talk into drastic drops of water temperature. This is common practice in Europ and I am convinced that this contributes to a large degree to the poor breeding results with this specie so far.

After reading this forum and other forums, I'd say exactly the opposite is true. Everyone seems to be following Paul B's recommendations. Which by the way, is essentially the same temperatures you're recommending. To say that the poor breeding results are due to being kept too cold is jumping to conclusions.

Michael has got it right. Keeping Laotriton,who are very sensitive to even the slightest change in water-temperature at freezing temperatures, like Frogeyes does, does not only not correspond with their natural needs but is, in my book, nothing short of crualty.

I'm not sure what you mean by sensitive? Like I mentioned earlier, mine are kept at a range of 1-23'c. Are they active? Sure are. Are they breeding? Yes. Are they healthy? You bet!

Have you actually researched their "natural needs"? If you had then you would have seen that they are exposed to these ranges in the wild and it's not as cruel as you seem to think.

[Henry Janssen]

Hello Justin,

Thank you for your sharp reply.

Could you please point out to me where exactly I can find the information on wich you base your opinion that it is justified to keep Laotriton at near freezing - temperatures, so that I can look it up.

Also please explain to me the chronological order of the maximum - temperature, the minimum temperature and the onset of spawning at 11°C.

Thanks,

Henry

[FrogEyes]

There is next to nothing available for temperature data on Laotriton habitats. The only data I have found is

a) non-specific hobbyist collecting data for one stream, reported as "sixteen to twenty degrees". I would note that no-one is collecting stream-dwelling salamanders in mountain streams during the coldest or wettest seasons. Those temperatures would be MAXIMUMs, obtained when water is lowest, slowest, and most accessible.
b) specific climate data for Xiang Khouang indicates a low temperature of -3C, which would be an air temperature taken near the former provincial capital, not a water temperature nor a temperature taken from a forested valley in the mountains.

The present weather forecast for Xiang Khouang shows a maximum daytime high this week of 23C and a nighttime low of 3C
Xieng Khouang weather forecast | Xieng Khouang, Phonsavan, Laos

My animals have shown NO signs of stress from cold temperatures. Newts are northern hemisphere animals, and even the southernmost species experience cool to cold temperatures as well as having a prolonged and extensive ancestry of species from more northerly and cool habitats. It's no coincidence that salamanders in Asia only extend their ranges southward into damp, forested mountain regions.

[Henry Janssen]

Hello Frogeyes,

Thanks for your informative reply. Sorry for my late reply: I had some urgent things to attend to.

In fact I had been searching through both the literature and the internet on several occasions myself and came up with exactly the same as you : next to nothing. To the information you mention, I can only add the remark of Brian Stuart in the discription of this specie that the water in the pools of the Houay Pa Tin stream (Saysamboun ) was quite cold in November. This does not tell me very much exept that it is different from very cold, extremely cold or icecold. Second addition is a measurement of 19°C water-temperature by Gustavo Espellargas in August at the location in Xiang Khouang where the animals that were sold in Europ originate from ( German article by Bachhausen & Espellargas ), but what we need here are water-temperatures during the cold-dry season ( November to February , with December and January being the coldest months).

The information I found on the internet about the climate in the Xiang Khouang province of Laos, is sometimes detailed, but, as you wrote, only gives the air - temperatures on the plateau itself, mentioning that it getts colder in the mountains. The freezing temperatures are usually restricted to the last part of the night and the first hour or so of daylight and do not occur every day. Later on in the day it getts considerably warmer and, depending on how many clouds there are, often reaches temperatures wich Belgians would call warm weather. But it still leaves me guessing about how low exactly the water-temperature dropps in the Laotriton laoensis habitat. I can imagine it to drop under 10°C at times but remain sceptic about near-freezing water-temperatures. In order for the water to gett this cold, the average air-temperature needs to stay around 0°C for a prolonged period of time higher up in the mountains from where the water comes running down.

From you I learn that Laotriton survive such low temperatures ( P.hongkongensis fall unconcious and drown at 2°C). I trust your judgement that they do not suffer from it nor show any signs of stress, so I take back my accusation of cruelty. I will however not try this out on my animals nor will I advice others to do so because I don’t see any need for it.

Detailed information might be found in Somphoutone Phimmachak’s Master’s thesis but chances are that the content will not be translated and not made public, out of fear for misuse by animal-trafficers, especially since she also discovered a range-extension for this specie in the Luang Prabang province.

Another question is: does Laotriton laoensis need these cold water-temperatures to breed succesfully ? Lett me try to explain why I believe that they do not need it but just have to deal with it.

Newts are indeed northern hemisphere animals and indeed even the southernmost species experience cool to cold temperatures. They inherited the same temperature preference for breeding from their ancestors as the more northern species have.

Northern species need, to different degrees, the low temperatures of winter in prepatation to breeding. They are stimulated to breed by rising temperatures in spring and effectively start spawning when the temperature has risen above the threshold-temperature.

Southernmost species however, face a very different climat, to wich they had to adapt. The time of year with temperatures suitable for breeding is not preceded by a period with lower, but by a period with higher temperatures. In adaptation, they are not dependent on a period of low temperatures in preparation to the breeding season, they are not stimulated to breed by rising, but by falling temperatures and effectivly start to do so when the temperature has fallen under the threshold-temperature. A well-know example that answerrs to this model is Paramesotriton hongkongensis, but it is also true for Laotriton laoensis and for an undiscribed Paramesotriton sp. of unknown origin called “Red Warty Newt” by Günter Schultschik (Salamanderland) .

I obtained 2 pairs of adult Laotriton laoensis in March 2006. By using a simplified version of the model, as given in my reply to Brian’s question, the females have laid over 200 eggs each, with a very high fertility-rate, year after year. They are laying eggs now for the sixth winter in a row. The lowest temperature they went trough since they are in my care was 15°C. It was caused by a cold-spell and lasted less than a week. The females stopped laying eggs after 2 days at 15°C, but started laying again a few days later when the water temperature restored to 19°C.

Based on these observations, I believe that L.laoensis do not need temperatures much lower than the threshold-temperature to breed succesfully, but acknowledge that they are confronted with such lower temperatures in their natural habitat and had to find a way to cope with it. Cold-spells play almost certainly a role in their natural selection, eleminating individuals that can not cope from the population.

Paramesotriton hongkongensis females stop laying eggs when the water-temperature dropps too low. My observations suggest that this could also the case for Laotriton laoensis.

If european keepers would keep their Laotriton at temperatures above the threshold-temperature during the breeding season, than I would agree with you that the poor breeding-results in Europ are caused by keeping them to warm. From what I hear and read I know that this usually is not the case. Instead I am convinced that people, in their attempts to make absolutly sure that their animals will breed, disturb them to such a degree that the newts break off any attempt to breed , wich would not happen if they were left undisturbed. Doing nothing apparently is a difficult choice to make.

The method I propose is very easy to understand, very easy to copy and has proven to work just fine for six years in a row. No need to complicate things more than is necessary. There are more than enough problems to solve further down the road. I can only hope that one or two people take me up on this, try it out and report back on their findings. For this year however, it might be a little too late.

Henry

[Rodrigo]

Originally Posted by Henry Janssen

Southernmost species however, face a very different climat, to wich they had to adapt. The time of year with temperatures suitable for breeding is not preceded by a period with lower, but by a period with higher temperatures. In adaptation, they are not dependent on a period of low temperatures in preparation to the breeding season, they are not stimulated to breed by rising, but by falling temperatures and effectivly start to do so when the temperature has fallen under the threshold-temperature. A well-know example that answerrs to this model is Paramesotriton hongkongensis, but it is also true for Laotriton laoensis and for an undiscribed Paramesotriton sp. of unknown origin called “Red Warty Newt” by Günter Schultschik (Salamanderland) .

This also happens in other species in northern areas. All Triturus for example are known to be able to breed during the fall or winter. Variations on which time of the year they choose occur between individuals and populations. In my area, for example it´s perfectly normal to find T.marmoratus and S.salamandra breeding in mid fall. It also happens, although perhaps more exceptionally with other european and asian species. Interestingly (not relevant since these are in captivity) my H.orientalis always start breeding in late summer or early fall.
It makes me think that perhaps what trully allows for a normal breeding cycle is not so much the time of the year or the exact temperatures, but a healthy variation throughout the year which causes the necessary hormonal cycles. A "hormonally healthy" animal will then breed when conditions are suitable. Does that make any sense :P?

[Henry Janssen]

Certainly Rodrigo, hormones play a key-role.

Hormone production is stimulated by a combination of the year-cycles of different climatic factors.The temperature-cycle has a powerfull influence, but
several other factors, like for example changes in light-intensity, changes in lenght of daylight, changes in rainfall and others, can be, directly or indirectly, of importance. Breeding in it's turn is steered by these changes in hormone production.

How a specific animal's hormones react to the stimuli is an inherited characteristic. In species with a large natural distribution area, the hormones of animals from populations living under different climatic conditions may respond to different values of these stimuli or to a different combination.

In abcence of the correct stimuli, hormone-cycles gradually flatten and as a result, reproduction gradually comes to a halt. Recently ( less than one year) captured animals often are still conditioned ( hormonally-healthy as you call it ) from their time in the wild, and may reproduce in captivity once or twice even if the provided stimuli are not sufficiënt or incorrect.

Henry

[Chris Michaels]

"In abcence of the correct stimuli, hormone-cycles gradually flatten and as a result, reproduction gradually comes to a halt. Recently ( less than one year) captured animals often are still conditioned ( hormonally-healthy as you call it ) from their time in the wild, and may reproduce in captivity once or twice even if the provided stimuli are not sufficiënt or incorrect."

I have certainly found something like this to be the case in Paramesotriton cf. fuzhongensis, which I bred for three years, with a decline in clutch size and fecundity until no breeding occurred at all. I believe now that the animals were not getting wamr enough in the summer to induce breeding during the cooler winter (during which temperatures fell to an acceptable level).

I think that, in general, Paramesotriton (to which Laotriton are functionally most similar) are often kept too cool, when , in my experience, several species have bred only once summer temperatures get to around 21-22C, in my experience. Juveniles, too, do better under almost subtropical conditions (between 18 and 22C, with access to some cooler spots), which avoided some of the shedding problems and refusal to eat often encountered in this group. Of course this will differ between species (e.g. P. zhijiensis experiences constant temperatures of 16C year-round in it´s spring-fed pool). It is also worth noting that most of the species (other than probably the most aquatic ones, probably including Laotriton) are terrestrial for most of the non-breeding season (one estimate of the breeding season for P. hongkongensis is 45 days, the rest of the year spent in deciduous forest near to the water). Sorry to wander slightly into a different genus, but I think, in general, the ´rules´that apply to Paramesotriton are the same as those that apply to Laotriton, as both are large newts breeding in step pools in larger upland rivers in deciduous forest in tropical south-east Asia, and which are not wholly adapted for an entirely aquatic life (unlike Pachytriton).

If anyone has several pairs of Laotriton, one way to settle the discussion would be to maintain groups under each of the proposed breeding strategies and see which has more breeding success. Would anyone who has a larger group of these animals be willing to try this?

Thanks

Chris

[GE]

Mine started laying this week. They coloured up in December. My tanks are in the basement and it is cool come November..as I live in northern Ontario. The basement cools as the weather does. We have a heated basement, but we keep it 60ish F. Some mornings are cooler down there.Interestingly,the female seems to have stopped laying as we are in a cold snap and that has cooled off the basement quite a lot. I've not been watching the water temps closely but I'd say it's low to mid 60s today. The males are still fanning and courting like mad though.

[Henry Janssen]

Just published:


Phimmachak,S., Stuart, B.L.,and Sivongxay,N. ; " Distribution, Natural History and Conservation of the Lao Newt ( Laotriton laoensis ) ( Caudata: Salamandridea )."
Journal of Herpetology, Vol.46, No.1, pp. 120-128, 2012.


The following temperatures are given:


Pa Tin Stream / 7 june 2007 / watertemp.: 25 °C / airtemp.: 27 °C
Sang Kat Stream / 8 june2007 / watertemp.: 21 °C / airtemp.: 23 °C
Sang Kat Stream / 7 april 2008 / watertemp.: 19,5 °C / airtemp.: 22 °C
Thongkham Stream / 6 april 2008 / watertemp.: 18 °C / airtemp.; 18,6 °C
Pieng Stream / 11 june 2007 / watertemp.: 18,5 °C / airtemp.: 20 °C
Lueng Stream / 1 april 2008 / watertemp.: 19 °C / airtemp.: 23 °C
Hin Rup Stream / 21 october 2008 / watertemp.: 18,7 °C / airtemp.: 20 °C
Madao Stream / 21 october 2008 / watertemp.: 13 °C / airtemp.: 17 °C

[FrogEyes]

I've been waiting for that paper. It's a good start, although what's posted is quite the hodge-podge of data, with only three months included, and then with only a single locality including data for two of those months. There are no data there for the four hottest and four coldest months. It is reasonable to expect natural water temperatures at some localities to either exceed 25C or drop appreciably below 13C, based on these data as compared to climate data for Louang Prabang. There is a bigger seasonal temperature gap between the survey months and the cold season than between those months and the hot season.

[Henry Janssen]

This paper is a valuable contribution to the knowledge of Laotriton laoensis, but I agree with you that, at the same time, it leaves many questions unanswerred. I too hoped to find more complete data on the water temperatures, in particular those during the dry - cool season. In their absence we are left guessing and speculating a while longer. Lett's hope that further papers will soon allow us to switch from guessing to knowing in the interest of the animals in our care.