E. andersoni eggs

[TJ]

Here is what an E. andersoni egg looks like:

In anticipation of questions, yes, it's CB; no, I'm not the person who bred them; no, I don't possess specific info on how to breed them; no, I am not a source for them, especially as this species is now fully protected; and yes, that's about as far as I'm willing to go

(Message edited by TJ on April 22, 2005)

 

[paris]

how many do they lay?

 

[TJ]

I don't really know. I seem to recall up to around 20 but have to check. There can be a tremendous difference in the size of females depending on the island they come from and on age, so the number of eggs laid may also vary significantly. What I do know is that the eggs are <u>never</u> laid in the water, but instead in moss and under leaves and the like near water or above the water line. This takes place between February and July. The eggs take 3-4 weeks to hatch and the larvae take 2-3 months to morph.

 

[paris]

do the females gard them in any way or do they just lay and leave?

 

[TJ]

Lay and leave, I think, though I read somewhere that after laying eggs in moss, for example, they sometimes will nudge the eggs deeper into the moss for protection. The hatched larvae fall or wiggle their way into the water. Since the newts neither mate in the water nor lay eggs in the water, the larvae stage is the only time in the newt life that it hangs out in the water, I'm told.

 

[paris]

too cool!..i indeed have camera envy...

...is this one gong to become a photo series?

 

[TJ]

Well then, here's another

Normally, the eggs are never in the water. This egg just happened to fall into the water and I photographed it before retrieving it. The eggs can develop fungus if left in the water.

(Message edited by TJ on May 09, 2005)

 

[TJ]

 

[jennifer]

These are just amazing (HUGE!) eggs. Thanks for the photos, Tim.

 

[pamela]

AWESOME Tim!!!

 

[TJ]

Cool, eh?

The eggs' lack of transparency, by the way, is on account of their high viscosity at the time they're laid.

 

[TJ]

 

[ralf]

Great pictures Tim. Any hint as how close they are to hatching?

 

[TJ]

Thanks Ralf. I expect to get my first hatchlings over the next day or so. I was told that stimulation of the eggs at this stage (by excessive misting, etc.) can lead to premature hatching, so I'm being especially gentle with them. I should note that the eggs have become progressively transparent, with a few exceptions.

 

[TJ]

I'm experimenting with two hatchery models/methods:

<font size="-2">(the eggs that were on the left side of the tub have been transferred elsewhere)</font>

This method -- what was recommended to me by an experienced breeder of this species -- involves placing the eggs on firmed-up mass of sphagnum moss in a tub with 2-3 cm of water so that moss remains damp. I have raised all the eggs this way to the pre-hatch stage. The unsupported moss on the margins of the moss mass inevitably breaks up, and it is through openings between floating moss that the larvae are to enter into the water upon hatching.

But it occurs to me that this method would be more effective in a 90 cm x 45 cm aquarium as with a small tub, water quality can be more easily compromised, water changes are somewhat awkward, and it will be somewhat difficult to find and recover the larvae once they hatch.

Here is my self-improvised method for the pre-hatch stage:

It involves placing the eggs on a patch of live moss in the middle of a tub. The moss is supported by rocks that are surrounded by water for the larvae to fall into upon hatching. The eggs are covered lightly with Java moss to prevent drying and misted occasionally to be on the safe side.

Some Egeria densa could be added to the water to help keep it fresh, but I've been told that E. andersoni larvae seem to fare poorly when airstones are used. In any case, the larvae will be transferred from both setups shortly after hatching to a 90 cm x 45 cm tank to be raised.

(Message edited by TJ on May 11, 2005)

 

[TJ]

Paris, according to my info here (Utsunomiya), they generally lay 50-60 eggs, usually all deposited in the same location. But some are known to lay as many as 100 eggs. There is indeed some geographical variation

Most eggs are hard to see through but you can just make out the embryo in this one:

(Message edited by TJ on May 11, 2005)

 

[TJ]

I've since simplified "Method 1" like so:

 

[carlos]

Hi Tim, do you think that is that necessary to provide a heavy rain when they in the breeding season???

 

[TJ]

Hi Carlos,

I really have no idea. Having never bred them myself, I would only be guessing...and wildly at that

But the person who bred these this year as in previous years didn't do any such thing, as far as I know. It's probably more temperature related than precipitation related.

Only three eggs left to go, and I may opt to surgically assist the hatching process since they're so behind....

 

[TJ]

I released one yesterday and the final two today. I'm generally in favor of letting nature take it's course -- but only up to a point

These last few eggs failed to hatch even though I have had them since April 21 when they were already a 1-2 weeks old. They are said to hatch in nature in 3-4 weeks but it's been 6-7 weeks! Having said that, almost 2/3 hatched naturally.

As you can see in the above pics, these encapsulated larvae had not only about absorbed their yolk sacs but had also developed forearms while still in the sac! Anybody know if this known to occur among other species?

I guess I missed my calling in life as all 10 or so extractions I performed were successful

The trick is in not harming the larvae while making the initial incision, even though they are prone to move suddenly, and then preventing the outer skin of the egg from wrapping tightly around the larvae once the jelly is expelled. The latter happened in a couple of cases, but the problem was resolved.

Today I witnessed the larvae eating tubifex for the first time. Before I wasn't sure they were eating it, though I'd seen them eating baby brine shrimp.