difficult to tell from the pic, my guess however would be male as well.
Dovii tend to be pretty shy and hide most of the time until they are over a foot long. Cant quite tell how big this one is, but I would expect it to be shy until a bit larger.
I would also recommend a red tiger motaguense instead of a dovii for a 150, unless you plan on upgrading in the pretty near future. Red tiger motas are beautiful and have just as much attitude, and won't outgrow a 150 like a Dovii will.