Sorry this is late in the day. Went fishing, got the pump in the well for the garden, took care of rhubarb and gooseberries. One must have their priorities right.
"Spines evolved for a reason - and not only in catfish. It's known that the high bodies and sharp spines on the dorsal fins of sunfish and other panfish deter predation by fish like pike. The protective effect of spines is seen on an even smaller dimension. Small sunfish eat large number of tiny crustaceans, call water fleas(Daphnia). One species, Daphnia lumholtzi,has a long spine, so when a small sunfish gets one lodged in its throat, the strike rate on members of the this species decreases dramatically compared to short-spined species of Daphnia." In "In-Fisherman" June-July 2007 Rick
