Water incubating N. Rachovii eggs

[arvin555]

I have mentioned in my self intro, that we are keeping N. Rachovii, and was able to collect some eggs. I'd like to report a recent findings about my experience with water incubation.

When I collected eggs I separated most eggs and bagged them, and collected 10 to try out water incubation. The label says 8/30/07 collection. Basically the eggs that were wet incubated were not dried at all, except when they were transferred to the water inclubation bottle.

Last week, I inspected them and saw that a few eggs have eyed up, but didn't think they were already ready to hatch. This morning (10/7/07) because we were scheduled to fumigate the house against cockroaches, I put a cap on the bottle (but didnt inspect them), then when I got back this evening, I decided to inspect the bottle and was surprised that after stirring the water around to see the eggs, a fry greeted me! At first I my thoughts were "oh no it hatched and died already" but it moved, so I decided to move the fry to a separate container. We'll see if it survives, I have not had much luck keeping the fries to adulthood for my N. Guntherii, I hope it's different this time with Rachovii.

I am not sure if the fry hatched prematurely, I hope not, anyway it proves that most of the gurus here are correct, that with our temperatures one can get very short incubation times for Nothos.

In this case, it's just a mere 38 days! For a Rachovii. Water Incubated! Will inspect the bagged eggs how they are doing. Will report back.

TTFN
Arvin

[stoker]

Very interesting Arvin,
Sealing the incubation bottle is a trick that is used to force various species of Fundulapanchax species to hatch.
There are various links on the forum regarding this .


Mike

[stoker]

Hi Arvin

Have a look at this link http://users.pandora.be/marc.bellemans/Rachovii_E.htm and notice the comments about water incubation..

Mike

[timebomb]

Arvin,

Mother nature is very clever. She makes sure incubation times are not the same for every egg. This ensures the survival of the species. Think about this along the lines of evolution:

The Notho rachovii lives in places with distinct wet and dry seasons. The rains come and there's plenty of water everywhere. The eggs hatch and the fry develop into breeding adults in a short while. They lay their eggs all over the bottom of the ponds in which they live. For months, it does not rain and the ponds eventually dry up completely. There's not a single drop of water anywhere. All the fish die but their eggs are waiting in the mud for the next rains to fall.

Mother Nature understands that climate can be fickle. In certain years, the rains may come late. Occasionally, there's drought and the rains don't come at all. Or it might rain a little bit and a dry spell of a few weeks or months follows.

If every egg were programmed to be hatched in the same incubation period, one year of freak weather could easily wipe out a whole species. The Notho rachovii is a fish that has adapted to survive even in places where the ponds dry up completely during the dry seasons. This special ability must have taken millions of years to evolve. It would take more than just one year of freak weather to kill them all.

Loh K L

[arvin555]

Thanks for your comments guys!

Just an update, I was a bit surprised when I inspected the bottle again today and found there was a fry again, so I poured the water out to a different container to transfer it, and againg got surprised that there were 3 fries in total! That means the original 5 eggs that I got Aug. 30 were fully eyed (one egg was white with a fry in it). The rest of the eggs that I collected a few days after were still not eyed up at all.

Of course this is the first day of the fry, and because I have never been able to keep them for more than 3 days it is still uncertain if they will live or not, they are now being fed with infusoria and microworms.

Mike, thanks for the URL, really nice website, the water incubation thing you mentioned, did you mean the info that in 1962 they transported eggs in water and hatched after 5 weeks but were all belly sliders? Then again my current experience with N. Guenterii are all belly sliders too we'll see about this 4 fries that I have, I'll report to you guys of course.

Loh, thanks, yeah you know I noticed that already about the eggs, I mean only a few days difference and some of the eggs were still not eyed, and even in the same batch, I can see fry developing but some haven't really developed. So yup they do really hatch at different times.

Same thing with brineshrimps, maybe because of Killifishes, I started redrying and rehatching eggs, and get a second batch, same thing with fairyshrimp eggs.

TTFN
Arvin

[TyroneGenade]

In my experience, it takes 3 to 4 weeks to incubate eggs to "eying-up" of N. rachovii at 27 deg C. This result is 100% reproducable. Works for most species. Incubating at 27deg C breaks the diapause and then you get normal development.

To hatch, I simply add fresh peat and then wait for the healthy fry to appear. I have not had a healthy hatch from eggs simply incubated and hatched in water. There has to be peat present (for me at least).

I wrote an article to the BKA on this a while back. I will see about loading it onto my webpage.

Regards

[arvin555]

Thanks for sharing your experience and observations Tyrone. So my experience is not that out of ordinary then?

When you say 3 to 4 weeks incubation though, did you water inclubate them or did you incubate by drying peat? Reason I asked is because I just inspected the eggs that I gave my brother, same batch as the ones that I water incubated, all of the eggs he has still have not eyed up. In fact the look like they are in diapause and have not developed at all. He is now thinking of dunking them in water to try to get them to start developing.

By the way the water incubation system I used was to put the eggs in a small PET bottle 1/4 filled with water, there is a bit of cocopeat because they just stuck with the eggs, etc. Then I aerate them with just an airtube, with enough bubbles to give water circulation but not too much that the water is boiling like crazy.

I have started another batch and will report my observations here as well.

Tyrone if you can upload your article to your site that would be really nice reading, please post the URL if you are able to upload it.

TTFN
Arvin

[stoker]

I agree with Tyrone in that there is a need to have peat when hatching , to reduce belly sliders in fact I very rarely have belly sliders when peat is used.
The temperature can have a big impact on the incubation time , if the temperature is too high , this can reduce the period of incubation and make it far too short leading to the fry not developing correctly result belly sliders.
It`s possible to hatch in far less than a month with temperatures above Tyrones 27 C but the end result is poor , and my choice is to try and keep the temp at about 25 C .
It`s really a matter of try and see what works for you,, 27 C for Tyrone 25 C for myself.


Mike

[arvin555]

I'm almost sure that when you guys say peat, it means peat moss right? Because I am using cocopeat or Coco coir, which is different and won't make the water acidic.

An alternative maybe is to use Indian Almond Leaf (IAL)/Ketapang leaf, this probably has the same effect as peat!?

Update: For the first time since I have tried hatching Nothos, the fries have actually lived more than 4 days! The 4 fries that have hatched after water incubation of around 1 month are still looking okay, they are still mostly at the bottom, but most of them would sometimes swim up to the surface.

They are being fed infusoria and microworms, though I have doubts that they are taking the microworms already. I have yet to actually observe them eat though.

Tyrone, sorry I still am interested when you said you get 3 to 4 weeks incubation, is this water incubation or Dry peat incubation?

TTFN
Arvin

[stoker]

Peat moss is correct not cococoir or what ever it is called. If you get PEAT make sure if it`s for garden use that it has no additions to it. The peat will make the water acid and also stain it due to the TANNINS in the peat ( like weak tea) , there are substances in the peat that help reduce fungus etc.
Also add salt at the rate of teaspoon per gallon to reduce VELVET even to the hatching water use this rate.
If in doubt you can use jiffy plugs thin discs of peat in a net that expand when put in water , I use them as they swell up overnight and after removing the net there is enough peat to place in a lidded container with a hole in it that allow the pair to enter when spawning.

Mike

[arvin555]

Thanks for the clarification regarding Peat Stoker! I think we have some in stock. however I really wonder if Indian Almond Tree Leaves or what we call IAL or Ketapang leaves will do the trick. Betta keepers use IAL to make water acidic and it does give tannins as well. We'll see if I'm willing to experiment

Update, 2 of the water incubated fries are now swimming on the surface of water, which I think is positive news, at least for me, I have never had this when I was trying to hatch the Guentherii eggs. So it is looking good.

I am not sure if I should post this question separately, but don't you guys think that annuals that live in small pools will normally be inbred, because there is not too many individual parents to go around in a small pool over the generations?

This question arose as I am concerned with having our current collection of N. Rachovii, as it is now, we only have 1 Adult male and 2 adult females, we'll have 2nd generation soon hopefully, but the only ones I can breed them with are their parents or each other I don't even know yet how the sex ratio will be. But there is even a possibility that they won't be ready to reproduce before the parents might start nearing their end of life cycle and start dying!

Man I hope I can get in touch with a Asian neighbor who is a Notho collector so we can start swapping, etc.

TTFN
Arvin

[stoker]

Thanks Arvin

Pressed the button twice by mistake oops

Only takes about 6 weeks for the fry to become sexually active so should be able to cross breed back to parents.

got N Jubbi parents spawning and just hatched first batch of eggs be ready to spawn in about 2 months or so.

Don`t know about not using peat , have tried a lot of other things over the years but still go back to peat.

Mike

[arvin555]

Just an update, I am down to two fries and until now they are not really free swimming as I hoped, they tend to stay on the bottom of the container.

I also checked most of my incubating eggs and found that some of the 9/25 eggs have fries already, not fully eyed up but have eyes, compared to the 8/25 eggs from where 4 has hatched already, the rest still haven't shown any development. Thus showing that different eggs from same batch would have different rates of development, the eggs that I collected 1 month after have caught up!

Even some eggs in the moist peat have fries in them already.

TTFN
Arvin

[arvin555]

An update about the water incubated fries that I had. I now ony have one fry, still looks like a belly slider but at least still alive and at least it seems to be strong and swims fast. I'm pretty sure it is eating some microworms and am feeding some daphnia, which I think are still too big for it, though maybe they are producing daphnia nauplii that hopefully can also be food for the lone fry.

The other water incubated eggs are showing some signs of eyeing already, specially some of those that were harvested 1 month after the first batch. No hatching yet though.

TTFN
Arvin

[arvin555]

update again. Basically same thing, I put a cap on my water incubating bottles and after a day, most of the water incubated eggs have hatched.
Again however, most of them looked like belly sliders.

Then I inspected the same batch of eggs which were "moist" incubated in coco coir, and saw a lot of eyed eggs, so I decided to wet these as well. I got maybe 10 out of 50, and most of them were nicely swimming.

Unfortunately I made the mistake, because I wanted to save space, of transferring the 10 with the water incubated fries, so now I don't know which ones were from which incubation system, there are still belly sliders in the lot, but I am very happy to report that there are at least free swimming fries and most if not all (even the belly sliders) are actively eating infusoria and microworms and just now I fed BBS and some are big enough to catch and eat them already.

Some even make attempts at daphnia that I placed with them, but so far they are still small to be able to eat fully grown daphnia.

Summary of observations:
Well this is not 100% confirmed, but...
1. Moist incubated is probably better than water incubation.

2. I agree with the Theory that oxygen is important in development, with water incubation and also with coco coir or peat incubated. That is why I am now not a fan of putting the eggs in a plastic bag, I'd rather put them in a cup with a lid that can easily be aired daily.

There were a lot more eyed eggs in the a batch which I put in a plastic up with a not so airtight lid than the same batch that was in sealed plastic bag (which only yielded 4 fries out of 50 eggs)

3. There is so far a big percentage of eggs that either don't hatch or are not ready to hatch compared to those that have eyed already, so it is better to really start with a high number of eggs, at least 50. Then of course after wetting, collect the medium with unhatched eggs and reincubate. I am not in the process of doing this, so not sure how this will turn out. In any case 10 to 15 out of 50 is not a great percentage for first wetting.

TTFN
Arvin

[arvin555]

Just dropping by to update, my last entry here was November 2007 and it's now April 2008. Approximately 6 months, I was starting to wonder about my "Dry" incubated eggs and when I inspected them 2 days ago I saw some "eyes" so I said what the hey, they either hatch, won't hatch or won't hatch at all anymore.

This time I tried a new hatching water, which is water with dried Indian Almond leaf (for my Bettas), I dumped some in the plastic cup where the cocopeat and eggs were stored for 6 months.

Yesterday I was surprised to see a lot of fries in the container. I wasn't really ready for that, so I had to do emergency food preparations, luckily I still had a small infusoria culture going, and today I am starting to hatch some BBS.

If this hatching is sucessful, without belly sliders, then this might also be a good indicator that water with "tea" (slightly acidic with tannins) work well for Northos.

My previous hatching has only 1 male left, so I really need to have this batch grow to adult or else my collection will stop and I'll need to find a pair again somewhere! (Killies are very rarely sold here unfortunately, there is one shop that told me his supplier only sells males, how stupid is that?)

TTFN
Arvin