I don't know about other species, but I think the initial reports of this behaviour for compressiceps turned out to be greatly exaggerated (to quote Mark Twain). If I remember rightly, it was observed when a net full of assorted cichlids were thrashing around as they were hauled on board a researcher's boat. I think this was corrected in Fryer and Iles classic book about Malawi cichlids, but I am currently separated from my copy by a distance of about 400km, so I cannot confirm this.
