Help needed please

[dave fish]

just found a new information board erected on the canal near me where i fish regularly and stopped to read it especially the speciese that are found there ,now ive fished this stretch for nearly two years and caught most of them but they have added tench to the list and i havnt heard of any body who have caught one is this false info or is it a generic info sheet that they put up to cover the vast array of fish that can possibly be caught ?if there are tench in the canal what should i be looking for in terms of habitat ?and also they missed a few which i have caught such as eel and ruffe