Well as you all know I purchased a new baby long fin. I put the baby in with Spike my 7-8 month old. they are devided by a .25 inch piece of lexan which i drilled many holes in for circulation...
I was going to put the little one in a seperate tank but they seem to be getting a long very well. They even sleep next to each other at night time.(very cute)

here is what Spike is doing. He is digging up a big section of substrate and placing it up against the lexan that devides them. he actually has dug it all the way to the glass.. Now he/she is staying right by the hole that he dug. except to eat and sleep next to the little O..

My question is this. Why? and could it be that Spike is a female and the little one is a male and putting the little one in the tank has spurred Spike into spawning behavior? Spike has also become aggressive towards me when I do my water changes now (only when I am buy his hole

Please let me know I am very curious...

the little one is not matured so I doubt it a breeding thing. It could well be that the bigger one is trying to show some kind of dominance. Oscars often take substrate but that doesn't necessarily mean they're going to breed.

You never know, they may pair up if they are male and female, however I think you've got quite a long time to wait

yeah that's true thanks OFL on the opinion... I wish it was a year from now so they could pair off... I have a lot of people wanting babies if they do