i think it looks completely MALE, super designs within dorsal fin and tail (i have yet to see a female with these designs), trailers are NOT a very good way to determine sex as both can have them, as a matter of fact my female GT got pointed fins way before my male did (and my male looked just like yours does until a couple weeks ago they finally started to get pointed), GTs aren't really fast growers so as long as you keep your nitrates low (by keeping up with wc) and feed well then he should fill in on his own time, also have you seen his poo? GTs can be prone to parasites so make sure to watch out for that as that will slow his growth as well GOOD LUCK