How do seedless watermelons develop full seed holes without seeds to push holes open?

Question

Seedless watermelons have fully developed seed holes before any seed growth. How does that happen?

Answer 1

That is a good clue to the actual formation of the seeds! That will indicate that the seed space is already "programmed" into the genetics. Since they are designed by nature to reproduce, it would be safe to speculate that it will still imitate the process.

Now we get to how these seedless watermelons are produced...

They are hybridized in such a way that their genetic ploidy (their number of genes) do not match. This results in sterile offspring, not unlike a mule.

Here is an article that will offer more information: https://www.gardeningknowhow.com/edible/fruits/watermelon/seedless-watermelon-plants.htm