James is bang on- no spines at all. Racepics, if you catch a shark with white spots all the way down to the tail from the head without spines then it is a lemon. spotted spiney dofish have a spike on the dorsel fin and a grey in color and spiney dogfish are pink in color with two spines with white spots. spineys have teeth and lemons don't. lemons take cray and crab and spiney ( most of the time ) will not also.
make sure if you do catch a lemonfish and you want it for the table to take off the head and all the fins and tail " trunk the fish " so the meat doesn't taint and is prime for eating- clean it in salt water to take home.