I want to say female but want pros onions , dont mind the pleco poo, have a 16in sailfin with 2x 3200 gph wavemakers on each side tank and soon as the cut off, it looks like this an hour later
Could be female but my male went through a phase where he looked like that too so it's a toss up. I'd say try again at 5-6 inches. At Tigs point I'd say girl based on coloration but it still needs to grow into its body
Good luck, mine lives in a "community" but it's more along the lines that he tolerates the other fish and doesn't eat them and they say hidden and out of his way. Male or female it may snap males just snap more often and in a worse way. Just watch and be prepared to pull it.