Exactly Rockhopper.
Their mouth and teeth should tell it all.
At West Port the big lings will chase your smaller bait but once they see the bait at close, they just make a quick U turn.
If you got a 9 inch Greenling, you are guarantee to get a ling.
Most of the time, the ling is not even hooked; he just grabbed the greenling and would not let go.

Candle fish, eel, greenling, and small flounder is 10 time more affective than herring.