Measuring Your Catch

Another important aspect of getting familiar with the sport of fishing is learning the laws and regulations involved with the management of each species. Many anglers are used to thinking about size limits for different fish, but there are multiple ways that fish are required to be measured. Check the current regulations for a particular species to see its length requirements and how the length is determined. LDWF has set standards for each method, so everyone is on the same page when it comes to measuring a fish.

We recommend the type of ruler that has an upturned end upon which you put the fish’s nose, so you only have to focus on the other end. Remember to work as quickly as possible as many fish are frail and time out of the water must be at the minimum in order to increase the fish’s chance of survival.

Take precautions to prevent the removal of the slime coat, as this is the protective barrier against disease and parasites. Never use a dry rag or glove to handle fish that may need to be released. Reviving a fish in the water with a back and forth motion may be required to get the water flowing across the gills for a healthier release.

Total Length- This method is a measurement in a straight line from the tip of the snout to the extreme tip of the tail fin. The angler can rotate the tail or squeeze the tail fin to make it the longest possible length.

Fork Length- A measure in a straight line from the tip of the snout to the fork portion of the tail.

Lower Jaw Fork Length- A measure in a straight line from the tip of the lower jaw to the fork of the tail. This is the most common way to measure billfish species.

Curved Fork Length- A measure from the tip of the upper jaw to fork of tail measured along the contour of the middle of the body. In other words, lay a tape measure along the body of the fish from those two points.

Carcass Length- The measure from the curve of the posterior edge of the gill opening to the anterior portion of the caudal keel. This is used more in commercial fishing, where fish need to be headed and gutted for preservation on multi-day trips.