The one with the strange abnormal black marking on the gill cover is also deformed in the body. Note the notch in the back just above the caudal peduncle. Unless you are looking to develop a breed of deformed shortbody Firemouths that fish is not a viable breeder (not judging, look at the popularity of the Bloody Parrots and Balloon Rams!). The spinal deformity that causes that short body is almost always genetic, one of the few instances where deformed fish actually are genetically damaged. I would consider breeding it just to see if the odd color in the gill cover is also genetic, but personally would not continue the strain past two generations regardless.
