Hmm...I thought they were all a member of the sunfish family

...and so do a lot of other people, including Purdue University:

http://fn.cfs.purdue.edu/fish4health...ish_Family.htm

Cornell University must be mistaken also:

http://fish.dnr.cornell.edu/nyfish/C...rarchidae.html


And I've eaten all three and there really isn't much difference.