You got it Bubba! The "spines" are serrated and leave a jagged puncture wound, the "slime" is the "poison"! I still get gigged every now and then, but it's usually the little she-yits that get me... I'd much rather handle a 2-10 lber. than a 6"-12 incher, the smaller ones fins are needle and razor sharp!
I stepped on a catfish barefooted when I was a kid, and man what a mess! My foot swelled up 3 times the size of normal... couldn't walk!... I'll never forget that!