I was told by the store assistant that the blue Siamese fighter I bought 1 month ago was female. I've tried to attach a photo but I don't know if it will be accessible.
She is doing great, very healthy and has a great personality.

However 2 days ago I introduced a beautiful red male fighter. I found him dead this morning. He had been ravaged. All his fins were gone and he looked really awful. He was twice as big as my blue Betta.

Can someone tell me was this some disease perhaps or is my female actually male???

Besides the fins is there any other obvious way to specify gender in Bettas???

Thanks in advance for any advice you can offer.

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