DNREC has a pocket guide they released for anglers to identify invasive species. There is confusion between some species at times, especially bowfin (native) and northern snakeheads (invasive). Know your species.
The guides are only distributed through bait and tackle shops in areas that have the most contact with these species. Delaware Angler’s Pocket Guide For Invasive Species And Similar Species is free to the public. Anglers will also receive a guide after they submit a citation form to the Sportfishing Tournament for snakehead or catfish. DNREC has also given a copy of the guide to each of our Sportfishing Tournament weigh stations so they can ID the fish.
Bookmark this page so you have a handy copy, pictured below. DNREC has a lot of information on their website about invasive fish species, Northern Snakehead Alert.
Also check their page on Invasive Aquatic Species.