Protect New Jersey’s Waters

Fishing Regulations New Jersey Freshwater Fishing

Invasive Fish

Fish identification can be easy for species caught frequently, but tricky for species new to New Jersey waters. An untrained eye can mistake species that look similar.

Snakeheads are invasive and should be destroyed. They have been found in the lower Delaware River and some of its tributaries.

Bowfins, once believed to be native, are now considered to be an introduced species. Their impact, if any, on the state’s fisheries resources has yet to be determined.

Long anal fin.


Painting: Susan Trammell


Short anal fin.


American eels are a diadromous native species, using both fresh and marine waters during their lifecycle. These eels are found in nearly every waterbody in New Jersey. American brook lamprey are a harmless native species that serves as an indicator of clean substrate. The Asian swamp eel is an invasive species with documented presence in Silver Lake, a 10-acre waterbody located in Gibbsboro.

American Brook Lamprey—Native

No pectoral fins; gill slits present.

Asian Swamp Eel—invasive

No pectoral fins; no gill slits.

American Eel—Native

Pectoral fins present; no gill slits.

Although not a native species, channel catfish are stocked by Fish and Wildlife in select locations as a recreational and food species. The flathead catfish is considered an invasive species capable of causing ecological damage by out-competing other recreationally important species for food and habitat. Flatheads have been confirmed in the middle section of the Delaware River.

Upper jaw protrudes past lower jaw; tail deeply forked.



Lower jaw protrudes past upper jaw; tail not deeply forked.

Water Chestnut

Fan-shaped, strongly toothed leaves. Nut-like fruit with four sharp spines.

Pat Hamilton/NJDFW

Invasive Mussels—Zebra Mussels

How to Identify Zebra Mussels

  • Resembles a clam with a striped “D”–shaped shell, less than two inches long
  • Usually grow in clusters
  • ONLY freshwater mollusk that can firmly attach itself to solid objects
  • If found, keep the mussel(s). Note date and specific location. Immediately, call Dr. Peter Rowe, New Jersey Sea Grant Headquarters, (732) 872-1300 extension 31, or write prowe@njmsc.org.

Keep on Reporting

The most effective way to succeed in containing aquatic invasive species is to report each encounter. Anglers are reminded that possession or release of flathead catfish, snakehead, Asian swamp eel, brook stickleback, oriental weatherfish, green sunfish and warmouth, bighead carp, silver carp and grass carp (diploid) is prohibited. Anglers must destroy these species if encountered and submit specimen(s) to the Bureau of Freshwater Fisheries at (908) 236-2118 for north Jersey and at (609) 259-6964 for south Jersey. For photo I.D. confirmation, write us at njfwfish@dep.nj.gov.