Here's another photo if that helps!

That's part of the vascular system of the fruit. It carries nutrients and sugars inside the fruit sort of like blood vessels. Those seem over developed due to variety or growing conditions. It's safe to eat but probably doesn't make the best eating.

Great! Thank you for your help. I just cut around those "veins" and everything tastes fine.

Good lord, it is the end of January! How are you growing watermelon? In a greenhouse?

Although I like to garden, I didn't grow this particular melon. I'm temporarily living in SE Asia near the Equator. This melon was bought in a grocery store and grown in Malaysia, where they grow year around.

I just bought watermelon seeds. It gets really hot here in summer! I was hoping you would get tons of advice. So I'm on my own, but looking forward to the adventure!

Suzi