both those fish belong to the SUNFISH FAMILLY .. witch is also part of the panfish familly witch include's yellow perch , crappie , bullhead catfish .. walleye and white perch are not part of this familly..
the fist fish is a bluegill , the blue dot or gill extension is were it's name comes from...
the second fish is called a PUMKIN SEED another type of SUNFISH ..
there are many types of sunfish EX: red ear , red breast , pumkin seed , blue gill all cross breed ..
crappie and sunfish do cross breed but not to commonly heard of it's possible they are very similar . put it to you this way if a managuense(jaguar) and a convict cichlid breed together then a blue gill and a crappie should have no problem gettin it on ..