I have been talking about killifish in my last few blogposts—I am in absolute awe of them. The way they reproduce is just amazing. In this installment, I am going to show you another very interesting phenomenon—the process of eclosion.
When I got some eggs of Blue Gularis (Fundulopanchax sjoestedti) in peat, I simply put the peat in a cup and filled the cup with water. In an hour or so when the peat settled on the bottom, I could see free swimming fry. That made me wonder, how does this happen? How fast does it happen?
To answer these questions, I decided to take closer observations. I took some eggs from the peat, placed them in a petri dish, wet them, and made video of the whole process.
After soaking the eggs for 5-10 minutes, you can see movement inside the eggs. You can clearly see the fry moving inside as if they are trying to find the best spot to come out from. In the next 5 minutes they start breaking the egg shell and you can see tails or heads emerging from the eggs.
Within a few more minutes the entire fry was out of the egg’s shell:
Here is the video that I made. The video shows the progression in ascending order. Wetting the eggs, movement inside the egg, eclosion and then finally free swimming fry.
I hope you all enjoy these observations as much as I enjoyed making them.