Oversized C. ensicauda larvae (continued)

[TJ]

This is a continuation of the thread found at:

http://www.caudata.org/forum/messages/13/6959.html?1078238978

It's now at over 8.5 cm without showing any signs of morphing. I've informed Japanese herpetologists and have been told that this is the first recorded case of a C.e. larvae reaching this size without morphing, and that it might well also be the first recorded case of a neotenic (paedomorphic?) C.e.

 

[TJ]

 

[john]

Let's see if it becomes sexually mature

. It looks like a female to me. Congratulations

.

 

[nate]

It still doesn't have that "neotenic" look to me, just a very very very large larvae. I bet it transforms this spring. Sorry Tim

 

[TJ]

Well, you must admit, I did get your attention

I'll take that bet though. It's around six months old already and I recall John saying months ago it looked like it was going to morph. I just can't see that happening..or won't allow myself to

 

[paul]

Hi Tim,

very interesting information!
I will give no new speculation.

Let us see what happens!

Paul

 

[TJ]

Sorry Nate, but it didn't transform this spring, so you gotta pay up

Here it is from last night:

How long before I get to officially pronounce it neotenic?

 

[paul]

Hi Tim,

what is its total length now?

Paul

 

[TJ]

Hi Paul, I didn't measure it this time because it didn't seem to be any larger than the last time I checked. But I'll measure it soon and let you know

 

[edward]

Hi Tim,
I had a C. cyanureus at work that grew up in a dark filter still not transform at a little over two inches in length. It was sent to another Zoo so I didn't get to keep it and see it transform.

Ed

 

[TJ]

Veeeery interesting, Ed. As far as you know though, did it indeed transform? If you don't know, it'd sure be nice if you could inquire after it

 

[edward]

Hi Tim,
I can try and track it down but it will take awhile.

There is some evidence in some other species of amphibians (anurans) that lack of light (or low light levels) will retard or prevent metamorphosis.
Ed

 

[shawn]

most of the time neotony is caused by some form of environment or food etc like maybe try changing the lights around a lil increasing it some. or cool the water more. check your ph, amonia and nitrate levels as well because if your amonia or ph are out of the norm for them it has been known to cause issues.
Wolfie

 

[TJ]

Hi Ed. I'd really just like to learn if there have been any (other?) recorded cases of neoteny in Cynops, other than the presumably extinct C.wolterstorffi.

Interesting what you said about light levels, though they shouldn't have been the major factor in the case of my C.e.p larvae as it was kept in the same conditions as its siblings but was the only one not to morph.

I'm still taking bets on whether or not it'll morph this summer. Care to put some money on the table?

 

[TJ]

Hi Wolfie,

Thanks for the input, but I'd have to guess there are no ammonia or PH issues with its tank water, which is half-changed a couple times a week. Also, the newt has been moved from tank to tank since failing to morph, being exposed to different environments. It's now isolated, but there's absolutely nothing different between the way I've kept it and the way I've kept all my other C.e. larvae that have morphed. So there's got to be another explanation other than environment. I think that'd be genetic.

There's simply no account that I'm aware of, and I've checked with several Japanese amphibian experts (including three university professors) who attest to that. They all say it's an unexplained anomaly and that I should keep a close eye on it. If it was environmental, surely there'd be other cases of ensicauda not morphing after several months. There's also the fact that it's being kept at room temperature, and is not being chilled in a fridge, for example.

 

[edward]

Hi Tim,
They had it die without transforming almost a year after we sent it to them.

Ed