It is to help those interested readers get an idea of how small the fry are.
My fry were one week old on Monday.
As a reference, the line below is one inch long.
If it looks one inch long on your monitor, you'll be seeing the fish at their actual size. Be warned, young fry are so small that they will appear as little more than specks.
. Betta egg: 0.03 inches in diameter
One day old fry: 0.1 inch long (The tail doesn't show at this scale)
One week old: 0.2 inches long.
Two weeks old: 0.25 inches long. (Starting to show dorsal fins.)
Three weeks old: 0.34 inches long
Four weeks old: 0.45 inches long on average.
Five weeks old: 0.6 inches long. Size ranges from .5 to .75 inches.
Six weeks old: 0.85 inches long. The largest are over an inch.
Seven weeks old: 1.1 inches long.
Eight weeks old: 1.3 inches long.
Nine weeks old: 1.55 inches long.
Ten weeks old: 1.7 inches long
Eleven weeks old: 1.9 inches long
After eleven weeks of growth, the amount of week-to-week change is too little to be interesting. From then to seven months of age the betta's body shape stays the same with a very slow increase in size. The fins grow at a glacial rate, eventually developing their full length at seven months.