My Killifish hatching experience

[Slaigar]

This week I begun to finally start hatching my eggs. It is about two and half months since I received them. My hatch rate them varied quite a bit.
Sorry if I mess up names!


N. sp. Caprivi:
I got absolutely nothing out of this bag. The peat is going to be dried and rewetted in a month. Hopefully there is something here.

N. korthausae "kwachepa"
Around 10 fry out of this bag.

N. ugandensis "Butiaba" 3km N, UGJ 99-13
This one made me happy. Probably more than 20fry swimming around. At a quick look, none of them are belly sliders.

Austrolebias charrua "Ruta 9km 345" Chuy F1
Ok, this where I was surprise, or more horrified. Around 20 fry hatched but only 3 were freeswimming. The rest of the them were belly sliders. One main difference in the hatching container was the colour of the water. The water column was not tannin stained. I am going to try every method that I can to hopefully get these guys swimming.

Other than just the peat, is there anything that could have contributed to it? All eggs were stored in my room with temperatures ranging from 19-23 degrees Celsius.

I have not done a count yet of the fry but I will do it later on in the afternoon.

[TyroneGenade]

N. sp. Caprivi:
I got absolutely nothing out of this bag. The peat is going to be dried and rewetted in a month. Hopefully there is something here.

These are tricky fish. Did you see eggs? There will often be very many but they won't hatch because: 1) they are not ready or 2) they are too old... It could also be because of the heat they are well past their sell by date. They tend to give a lot of belly-sliders too. If you only got 30 eggs in the deal you may be in trouble...

N. korthausae "kwachepa"
Around 10 fry out of this bag.

Always a croud pleaser. =D>

Austrolebias charrua "Ruta 9km 345" Chuy F1

A trick with Austrolebias is to wet them with cold water (by cold I mean water of about 4 to 16°C---ok 4°C maybe too cold....). If you use warm water (room temp in SEA) you get a lot of belly-sliders.

Are you using oxygen tablets or peat extract? It is always a good idea. We hatch all out eggs here with oxygen tablets and get very few belly-sliders.

Hope this helps.

Ciao

[Slaigar]

The date of collection on the N. sp "Caprivi" is June 12. The temperature in my room never gets above 25. I am hoping that it is too early rather than too late.

Another look at the N. ugandensis and there are some belly sliders. Though thankfully not at the same extent as the Austrolebias charrua. There are quite a lot of them freeswimming so I am happy about this one.

I added peat extract to the container with the Austrolebias charrua fry just in case. Even though it is probably too late, I got nothing to lose. The number of fry freeswimming is still quite small- maybe around 4-5. I plan to raise the rest of the belly sliders on their own in a different container.

[TyroneGenade]

Caprivi take 3 to 4 months to develop. I suggest you rewet them in at most 4 weeks time. The wetting will of stimulated their development.

I'm not convinced peat extract helps fill swim bladders... oxygen tablets certainly do in my opinion. Using cool oxygen water to hatch eggs also helps a great deal. I suggest you get some oxygen tablet for when next you wet the Caprivi peat.

tt4n

[whuntley]

I don't know about these oxygen tablets you mention. When I need an immediate shot of oxygen in a tank, hydrogen peroxide from the local drug store ("chemist" to those still clinging to colonial roots) is a cheap and easy way to get it.

Wright

[TyroneGenade]

Dosing tanks with hydrogen peroxide scares me... kind of like looking over the edge of railing of high buildings. I know it is perfectly safe unless one does something stupid but stilll... Why chance it. I think this is called paranoia.

[Slaigar]

Thanks for the tip Tyrone, I will wait a bit longer to wet the Caprivi eggs.

[Slaigar]

More of the A. charrua are starting to finally become freeswimming. What a relief! There are now around 10 of them that are doing good. I can spot some of belly sliders having curved bodies. Is that a sign of a too early wetting?

I will have to check for sources on the oxygen tablets.

[TyroneGenade]

That some of the previously belly-sliding fry are becoming free swimming suggests to me that they were premature babies. I have had this with orthonotus in the past.

Of course it could also be your snake-oil peat extract...

tt4n