The size disparity is increasing, the largest is around 1 cm by 0.5 cm by 0.5 cm and the smallest one is around 0.8 cm by 0.3 cm by 0.2 cm.
The fry are starting to display their territorial instinct, some are protecting a small circle during feeding and nipping anyone who trespass it.
One concern I have currently is that they are hanging around the surface. This could be due to serveral factors.
- Foul water
- Colder weather since it has been raining constantly for the past few days. Thus they flock to the surface where it's closest to the aquarium light.
- Development of Labyrinth organ
The second factor could be possible. It has been rather cold these few days as it has been raining.
The third factor is most likely. I read somewhere that fry will develop their labyrinth organ when they are a 30 days old. Another evidence pointing to this possibility is the blowing of bubbles as seen in the picture below.
Look at the amount of air bubbles at the surface of the water. Here's one more photo from another angle.
As you can see the fry are starting to look like mini betta. Stay tune for week 5 update. If anyone has betta tanks for sale, kindly send me an email at firstname.lastname@example.org