Two different fish.He has Herichthys cyanoguttatus Texas Cichlid. You have Herichthys carpintis sometimes called green texas cichlid but i've always used Pearlscale Cichlid as common name.I know you all know these are two different fishes but i all so note that no one in linked thread gave this common name.
Can't tell sex of fish.I have one i'm pretty sure is a male and if i go by mine i'd say yours is female.Mine is about 6" and seems taller in body,and i think getting a hump.Just a guess though.
it doesnt matter both texas and carpintis will have the black blotch if they are female, try to get a pic with his/her dorsal up, either way its a SWEET LOOKING FISH!!