Max Sparreboom on aquatic rearing of C.e.popei

[TJ]

I just wanted to direct the attention of John, Isaiah and any others who are currently raising C.ensicauda to Max Sparreboom's excellent report found at:

http://www.callisto.ru/amphibia/max/mspage.files/cynops.htm

...for some interesting info and tips.

Specifically, this part:

"Rearing the larvae is unproblematic, but raising metamorphosed juveniles is more difficult and requires much individual attention. The metamorphs normally creep on land and look for moist places where they can keep their feet and rest of the body dry. Food given on land consists of springtails, mosquito larvae, Drosophila larvae and Tubifex. Even so, it is hard to control growth and who is eating what; the small containers in which the animals are kept can easily turn into rotting newt cemeteries within a day. I get the best results if I manage to keep juveniles in water. They are housed in small plastic shoe boxes with 2 cm water and some peat, moss and water plants, allowing them to sit in water with their heads raised out of the water. Food given in water consists mostly of mosquito larvae. Growth is usually slow, even when the animals are kept at room temperature all year. The young reach maturity in two to three years time. I have kept juveniles of C. ensicauda popei and C. e. ensicauda in this way, others have reared C. orientalis in this manner. For juvenile C. pyrrhogaster and C. cyanurus, which I only managed to keep on land, I am not aware of any results with aquatic rearing. For C. ensicauda it has been emphasised by many breeders from Gerlach (1934) onward, that the larvae and young must be kept warm (20° to 30°C), an observation that I can confirm. There is still much room for experimentation in finding out the best methods of raising the young to adulthood."

Has anybody else tried this technique (rearing morphs in shallow water)? I'm a bit confused

about what Sparreboom means when he says, "The metamorphs normally creep on land and look for moist places where they can keep their feet and rest of the body dry." Surely he means to say "wet"...right?

 

[ralf]

Hi Tim,
trying to force the morphing larvae back into the water bears a high risk of drowning for the animals. However, it is possible to adapt juveniles of this species to an aquatic setup again after an initial terrestrial phase. I will describe this in the new C.e. caresheet on Caudata Culture.
As always there are different ways to raise the animals. I just want to point out that Sparreboom did not succeed in keeping C. cyanurus juveniles in water, whereas Nate keeps them in an inch of water with lots of plants if I recall it right. Confusing eh?

No way of getting around close observation and adapting the setup whenever one gets the feeling that the animals don't feel comfortable (e.g. climbing the sides of the tank all the time). Some juveniles of C.e. may not adapt to an aquatic setup and will have to be kept terrestrially, which also seems to be the way they usually grow up in nature.
I think Sparreboom meant to say dry, indeed. The animals will not thrive in a terrestrial setup that is dripping wet. A certain moisture respectively humidity is necessary however.

Ralf

 

[TJ]

Interesting stuff, Ralf.

I had assumed Sparreboom meant "wet" because he was talking the same time about aquatic rearing. I don't keep my own in a wet environment. I wonder if he kept his terrestrially for a some time before moving them into shallow water...

Well, what morphed newts prefer sometimes differs from what's most efficient from the newtkeeper's point of view

although I hasten to add that we should try to accommodate their preferences to the extent possible. As he points out, there's still much room for experimentation as to what works best. And as you said, close observation and adaptation are crucial!

Regarding the danger of drowning, do you think it would still be a concern if the water level were so low that it doesn't cover them? (or as he said, "allowing them to sit in water with their heads raised out of the water").

I haven't managed to been able to get mine to feed from shallow water (using frozen bloodworm), so I wonder how he accomplished it. Perhaps with live food. Then again, I haven't experimented much.

Yep, it seems that in nature they do not return to the water for as long as three years. I myself saw no juveniles in the water in Okinawa whatsoever. So forcing them to go aquatic is certainly not the most natural thing to do...I just want to know if it really works!

Very much looking forward to the long-awaited caresheet!

 

[john]

I think I know Max's article by heart by now, but thanks Tim. My own limited experience is as follows.

Martin sent me 12 popei metamorphs. About 75% of them were very small - 3.5 cm. These guys were a nightmare to feed (I have no tiny live food). I lost one after about a month. Thankfully they all started eating eventually (thawed frozen bloodworms on a cocktail stick as Tim uses sometimes). Now I have 7 in a tank with about 2 cm of water and about half the surface of the tank is an island of Java moss, about 1-1.5 cm out of the water. Most of these 7 were the first to accept food so they've done quite well now and are all about 5 cm. They're even eating bloodworms from a pile I leave on the island (i.e. no hand feeding is necessary for them any more, though I still do it to ensure they all eat something and leave a pile for seconds). They spend most of their time on the island and don't climb the sides unless I disturb them (accidentally hitting the tank or something- oops

). They settle down pretty quickly though and seem content on their island. They beg at me when I take the lid off so that's a good sign.

The other 4 are in a smaller tank with a similar setup but they are a bit smaller and were the last few to start eating. They rarely will sniff out food on their own although they're getting better at it, but they like to climb the sides to some degree so they're not 100% happy (they're doing this less and less now). My conclusion is that the smaller they are when they metamorphose the more they prefer dry conditions. These smaller guys have barely any signs of colour yet, although they're beginning to get them finally. I believe this is because they were undersized at metamorphosis so it's taking a while for the colours to come out. I should say also that they're climbing less and less now.

The 7 that seem content with an island rarely enter the water, although I see one in the water (as opposed to floating on it) occasionally.

I think these are marvellous little guys. I haven't seen newts hunt out dead food solely on appearance and scent before.

To anyone raising metamorphs of these guys may I advise patience, a steady hand (for the cocktail stick) and plenty of time. They seem to be worth it - they're fascinating little things.

 

[john]

Tim, I've managed to get mine to eat in the water, in fact even the smallest that used to refuse bloodworms seem to be more inclined to eat bloodworms in the water, although they seem to lose more from thrashing around with them than they do on land. If one wouldn't eat when I first got them I would put it in the water, put the bloodworms in front of its mouth in the water and it would usually snap.

As for the caresheet, I'm having sleepless nights thinking about it (must ... read ... Ralf's ... caresheet).

 

[jennifer]

I have heard stories of drowning from 3 different people, so I have to take them seriously. However, I hadn't heard those stories when mine morphed! And, somehow, none ever drowned. I kept all my ensicauda morphs (both Cee and Cep) in semiaquatic setups from the time they morphed onwards. I now have 1-year-old newts of both varieties that are sexually mature (up to 4 inches long).

The larvae morphed in a standard tank (about 4-6 inches of water) with a large flat island. When all of them had finished morphing, I lowered the water level. They fed on live blackworms, either in the deep water (some of them had no hesistation to continue going into the water) or in a shallow feeding dish. It may be "unnatural", but they never had the opportunity to get dry (they did have plenty of opportunity to stay out of the water, if they chose).

Here are a couple of pictures of setups I used.
First, still with deep water during metamorphosis:

Second, after water level was lowered:

Third, new setup for the nominates (which were smaller and less willing to go in water). Water is very shallow and has many places to rest, in as well as out of the water.

 

[ralf]

Well, I apologize for taking this long for the caresheet and causing sleepless nights for some of you. Hopefully the caresheet wont have the effect of a sleeping pill on you then.

Tim, one way of tricking them into dead food would be to feed a mixture of live and dead food organisms for some time, then leaving out the live stuff (e.g. tubifex or white worms in combination with formerly frozen bloodworms). John, I agree. Cynops ensicauda is the only species I have seen so far in which the juveniles feed like a bunch of hyenas on a pile of frozen bloodworms.
Yes Tim, the water level should be very low when adapting them to an aquatic setup again. I don't think Max Sparreboom was referring to freshly morphed animals though. From my own experience the animals have to leave the water directly after morphing. They will even do so when not yet fully morphed. They may switch from water to land for some time (usually just a couple of days) and should be kept in escape-proof containers even before they completely loose their gills.

Ralf

 

[john]

Jen - that's remarkable. I'm going to bear that in mind with my current lot of larvae.

Ralf - hyenas is the right word

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