Outdoor raising

[Mark]

4 months ago I placed some P.waltl eggs in a large, weed choked tub in the garden, partly because I didn’t have space (or time) to raise them and partly because I wanted to see how they would fair left to their own devices. The tub was once used as a daphnia culture and was quite well populated with invertebrates. That didn’t last long however because P.waltl have mighty appetites. I haven’t fed them so they’ve been reliant on mosquito larvae, cannibalism and whatever else falls in. Tonight I thought I’d check how they were doing and found some staggering growth differences. Remember, these are all from the same batch of eggs:

4.5cm Not far off what I'd expect for a larva of it's age.

3.5cm fairly small for a 4 month old larva

2cm This guy is seriously small for his age.

I suspect the larger ones have been quite cannibalistic based on numbers. Clearly the very small ones aren’t getting much sustenance but I find it interesting that they survive despite being out competed by the larger ones. I wonder how long they would stay as larvae? Years at the current growth.

Has anyone else left larvae to their own devices outdoors? I wonder if these growth patterns are common when food is scarce.

 

[morg]

I have raised various species of newt larvae outside in large water tubs through the years, and in most cases the larvae had very different growth rates as with yours.
In most cases I start the larvae off in these tubs, and bring inside shortly before metamorphosis

 

[rigsby]

I've just done the same ,its like a newt lucky dip, all the eggs i didn't want to raise went into the one large tub to at least give them a chance. Now i see some large larvae swimming around and i would say they are all marbled newts but as these tend to swim in mid water there may be more in the leaf litter in the bottom..