YWG pairing

I picked up what I thought would make a good pair. A larger dull watchman, and a much smaller typical looking bright yellow. Both from the same small tank at the lfs.
In the past that is how my breeding pairs have worked out. One stays bright yellow, and one goes greyish. Never really had a problem pairing them up.

So not even an hour after putting them into the tank, the larger one turns bright yellow and proceeds to destroy the smaller one. Kills it.

I've not had this happen before. I wrongly assumed the larger was female, the smaller was male and ... you know, good things were going to follow.

So, any thoughts on pairing this one up? I don't see any way around it but to keep throwing them in till he he/she it decides to like one.

 

Or return the large one for two smaller ones of almost the same size, get them young.

I too have heard large females are grey in coloration.

I have a large older YWG that has been grey for years and is mean as all get out.

 

They are such a cool looking fish. They don't LOOK like they'd be mean but I guess they can be.

 

Two fish enter, one fish leaves!

 

I'm thinking I'll pick up another this weekend. I'm unsure if the one I have is male or female, but I'm leaning toward it being male.

I'll just drop in another small one and see where it leads. If they don't hit it off pretty quickly I'll put it in the refugium and either try again or return it after any wounds have healed.

If I can find a larger specimen I might go for that over a small one. I'll have to make some calls and see whats available.