Illinois Crayfish Regulations: Licenses, Methods, and Penalties

Illinois crayfish regulations split cleanly along one line: catching for personal use or bait requires a sport fishing license, and catching to sell requires a commercial fishing license. Both are administered by the Illinois Department of Natural Resources under the Fish and Aquatic Life Code (515 ILCS 5/) and Title 17 of the Illinois Administrative Code, and each carries its own rules on gear, waters, and limits. Miss those details and the penalties climb quickly, from petty fines to felony charges.

Recreational Harvest

A resident sport fishing license costs $15 and covers fish, crayfish, turtles, and bullfrogs, except for endangered and threatened species.¹²

Legal gear is limited to two types, each with size caps:

Traps made of metal screen, hardware cloth, plastic, or nylon mesh. No wider than 24 inches in diameter, no longer than 36 inches, mesh no larger than half-inch bar measurement. Each entrance opening cannot exceed 1.5 inches in diameter.
Minnow seines no longer than 20 feet, no deeper than 6 feet, mesh no larger than half-inch bar measurement.

Any trap left unattended must be tagged with your name and mailing address.²

Two rules catch people out. Crayfish you take recreationally can only be used on the body of water where you caught them. You cannot move live crayfish to a different lake or river. And a recreational catch is for personal use only. Selling or bartering crayfish taken under a sport fishing license is illegal.²

Commercial Harvest

Only commercial license holders may harvest crayfish for sale. A resident commercial fishing license costs $60, and every commercial fisher must also hold the $15 sport fishing license. Anyone helping aboard the same watercraft needs at least a sport fishing license. Each commercial seine costs $18 per 100 lineal yards or fraction thereof. Non-residents pay $300 for the commercial license and $36 per 100 yards of seine.³⁴

Commercial crayfish harvest is confined to one stretch of water: the Illinois River and its adjacent backwaters from the Route 89 highway bridge downstream. Several areas inside that stretch are closed, including U.S. Fish and Wildlife National Wildlife Refuge waters, the Donnelly/Depue Fish and Wildlife Area, the Rice Lake Complex including all of Big Lake, Meredosia Lake during central zone duck season, and Clear Lake in Mason County for the seven days before and during duck season.⁵

Seines are the only legal commercial device for crayfish. They can be any length but cannot exceed 6 feet in depth, with a bag no taller than 6 feet and mesh no greater than half-inch bar measurement. Traps and nets recreational harvesters might use are not authorized commercially.³

Mississippi River Reciprocity

Illinois has reciprocal agreements with Iowa and Missouri on the Mississippi. A commercial license from either state is valid on the Mississippi River proper, including contiguous backwater lakes. You cannot attach gear to the neighboring state’s bank or fish in that state’s tributaries. The boundary between states follows the center of the navigation channel as surveyed by the U.S. Army Corps of Engineers.³

Methods That Are Always Illegal

The Fish and Aquatic Life Code bans several ways of taking aquatic life outright: electricity or electrical devices, any chemical or acid, drugs or medicated compounds, and explosives including dynamite and nitroglycerin.⁶ These methods kill everything in a stretch of water, not just what you’re aiming at.

Penalties

The penalty ladder under the Fish and Aquatic Life Code goes higher than most people expect:

Petty offense, the default for most Code violations, punishable by a fine of up to $1,000.
Class B misdemeanor for many specific violations, including a range of gear and licensing infractions, with fines up to $1,500.
Class A misdemeanor for more serious violations such as using chemicals or explosives, with fines up to $2,500.
Class 3 felony for commercial-scale violations where someone knowingly captures, sells, or transports aquatic life in violation of the Code and the total species value reaches $300 or more.

Multiple smaller violations can compound. Convictions on more than one violation within a 90-day period totaling $300 or more in species value become a Class 4 felony.⁷

Any violation of the Code or its administrative rules can also mean revocation of your licenses and suspension of your fishing privileges.⁸ For certain repeat violations, the arresting officer can confiscate your tackle, gear, and watercraft. Confiscated property may be sold at public auction by the county sheriff, with proceeds going to the county general fund.⁷

Species You Cannot Keep

The rusty crayfish is classified as an injurious species in Illinois. Possessing a live one is illegal unless you hold an approved aquaculture permit with a specific letter of authorization from the IDNR.⁹ If you catch one incidentally, you may return it unharmed to the water where you caught it, but you cannot keep it alive, transport it, or release it into a different body of water.² Rusty crayfish are identified by dark, rusty-red spots on each side of the carapace and oversized claws with black bands at the tips.

Four crayfish species carry threatened status under the Illinois Endangered Species Protection Act (520 ILCS 10/) and cannot be harvested:

Indiana crayfish (Faxonius indianensis)
Kentucky crayfish (Faxonius kentuckiensis)
Shrimp crayfish (Faxonius lancifer)
Bigclaw crayfish (Faxonius placidus)

These species occupy limited ranges in southern and eastern Illinois. If you’re harvesting there, identify your catch before you keep it.¹⁰

Federal Rules on Moving Crayfish

The federal Lacey Act prohibits importing, exporting, transporting, selling, or purchasing wildlife taken in violation of any state or federal law. Illegally harvested Illinois crayfish carried across state lines add a federal case to the state charges.¹¹

The U.S. Fish and Wildlife Service also maintains an injurious wildlife list under 18 U.S.C. § 42 that restricts interstate transport. As of early 2025, the Service proposed adding the marbled crayfish (Procambarus virginalis), which reproduces asexually, meaning a single individual can establish a population.¹²

Cook Them Before You Eat Them

Crayfish can carry Paragonimus, a parasitic lung fluke that causes paragonimiasis. Larvae from an infected crayfish migrate to the lungs over six to ten weeks, causing fever, chest pain, fatigue, and a persistent cough that can produce blood-tinged sputum. Symptoms are sometimes mistaken for tuberculosis, and in rare cases the parasite reaches the central nervous system and produces meningitis-like symptoms. Midwest cases have been linked specifically to eating uncooked crawfish on river float trips.¹³

The CDC’s guidance is simple. Never eat raw freshwater crayfish. Cook them to at least 145°F (63°C). Pickling and salting do not kill the parasite.¹³

1
Illinois Department of Natural Resources. Fishing Licenses and Fees
2
Illinois Department of Natural Resources. 2024 Fishing Regulations
3
Illinois Department of Natural Resources. Illinois Administrative Code Title 17 Part 830
4
Illinois General Assembly. 515 ILCS 5
5
Legal Information Institute. Ill. Admin. Code tit. 17 § 830.15
6
Illinois General Assembly. 515 ILCS 5/10-80
7
Illinois General Assembly. 515 ILCS 5
8
Legal Information Institute. Ill. Admin. Code tit. 17 § 805.50
9
Legal Information Institute. Ill. Admin. Code tit. 17 § 805.20
10
Illinois Department of Natural Resources. Illinois Endangered and Threatened Species List
11
U.S. Fish & Wildlife Service. Lacey Act
12
Federal Register. Injurious Wildlife Species Listing
13
Centers for Disease Control and Prevention. About Paragonimiasis