Hatching bags from Uruguay and Argentina

I continue hatching annual killifish in small volumes of water at home, feeding the alevins with pond food. This week I wanted to hatch embryos from 9 bags with eggs which I bought on Aquabid, or otherwise. All bags came from Argentina or Uruguay. These bags are usually small and can become completely dry prematurely, killing all embryos in them. To keep the peat inside moist and the air with plenty of humidity, I used to put the bags on a sponge. This was then placed inside a plastic box with a layer of demineralized water on the bottom, keeping the air inside saturated. Disadvantage: the labels fade and bags need an extra waterproof mark. This time I checked the bags weekly and injected a few drops of water if necessary, using a syringe with a needle. This worked fine!
+ The hatching itself went like this: I added very cool water in the morning (14 degrees C), and let the temperature rise in the room during the day (to over 23). The amount of bellysliders was minimal.
Swimming are: A. luteoflammulatus, reicherti, elongatus, cheradophilus, nigripinnis, arachan. The week started well…

Hatching on a sinus

Last week, at the ECOTRON Ile de France research station, five students, one engineer and myself did a short experiment on hatching Austrolebias. We used a prototype of the ECOLAB developed there, to simulate a diurnal cycle with a ten degree temperature difference between night and day (going from 15 to 25 degrees). At four times during the cycle, we put embryos in the ECOLAB in multiwell plates and added 5 ml of “hatching water” to each well. We used about 400 embryos from several species.
The data will be analysed next Tuesday, but my first impression was that we had the least bellysliders when the embryos were wetted at 15 degrees, and the temperature went up to 20 degrees within the following six hours.
The ECOLAB consumes lots of energy and resources, so let’s hope our results pay off, that the outcome will make all our hatching more efficient. More on this next week.