it is in the photo section. i shoulda snapped some pics of the big one at seaworld sd. they got a nice 14"er atleast and it looks cool. imagine exactly how u see your lima acting, just bigger. still jumpy, stil skittish, just big lol.
though i can't find any scientific data on it, i think there are two distinct variants of the lima shovelnose, and one of them grows 24" while the other (more common) type is much smaller.
Just checked the dorsal area on my own Lima, and yes there are brown spots, cross checked this with Planet Catfish photos and yes spots again...here is the link....