Did you know there are over 3,000 known species of catfish? However, in North America, there are only a few freshwater and saltwater catfish species that pique angler’s interests. Typically, catfish are easily identifiable by their whiskers or barbels, with each subspecies having distinct characteristics from one another. Specifically, it would be best to learn how to identify catfish species to avoid running into trouble with a game warden. This article will look at the common catfish species and show you how to identify them.

How to Identify Catfish Species

There are many questions anglers typically have regarding how they can quickly recognize the difference amongst each catfish species. Like, what kind of physical attributes should they look at on each fish. Or how to figure out the gender. Thus, we’ll start by first examining how to tell if a catfish is a male or female.

How to Tell If a Catfish Is a Male or Female

In most states, you’ll rarely come across regulations on which gender of catfish you can pull up. However, if you are still interested in learning the sex of your catfish, here are some ways to tell.

  • Male catfish have broad, muscular heads with thick lips
  • Males are often darker than females
  • Pre-spawn females are filled with eggs
  • Males have brighter colored fins
  • Males have nipple-shaped raised genitals
  • Females have a rounded opening around their genitals

Common Freshwater Catfish Species

The most common freshwater catfish species anglers are known to target flathead, channel, blue, and bullhead catfish. Now, let’s take a look at what makes each species unique:

Flathead Catfish

A flathead catfish against a white background.

Flathead Catfish are known to grow to trophy sizes. For instance, the world record flathead, recorded by the International Game Fish Association (IGFA), weighs 123 pounds and is above five feet in length. As its name implies, the easiest way to distinguish a flathead from another catfish is by its broad flat-shaped head. In addition, to its distinctive head shape, other characteristics of a flathead catfish:

  • Scaleless, yellowish, olive-colored skin
  • Mottled back and sides with black and brown
  • Pale yellow or cream-colored belly
  • Protruding lower jaw
  • Slightly notched tail fin

Channel Catfish

A channel catfish against a white background

Channel Catfish are the most common catfish species across the United States of America. Additionally, channels are native to waters ranging from Southern Canada to Mexico. Unlike flathead catfish, channels don’t get nearly as large. For example, the world record channel catfish, recorded by the IGFA, weighs 58 pounds, and the longest one measuring just short of three feet in length. Here is a list of identifiable qualities channel catfish possess:

  • Scaleless, dark brownish to slate-gray skin on top
  • Silver to white skin on its sides and belly
  • Slender looking body
  • The upper jaw is longer than its lower jaw
  • Deeply forked tail fin

Furthermore, mature male channels tend to get mistaken as blue catfish because of their darker skin tone and lack of spots.

Blue Catfish

Blue Catfish against a white background.

When most people think of trophy-sized catfish, they usually think of flatheads. However, little do they know; blues are the largest and most migratory North American catfish species. The world record for blue catfish, recorded by the IGFA, weighs 143 pounds, with the longest one measuring over four feet in length. Often, blue catfish are mistaken for channel catfish because of their bluish-gray skin tone. So, here is a list of unique markings to help you identify blue cats more easily:

  • Scaleless, bluish-gray skin on top
  • Silvery white skin on its side and belly
  • Whitish colored fins
  • Wedge-shaped appearance
  • Long, straight-edged anal fin
  • Forked tail fin

Bullhead Catfish

A bullhead catfish against a white background.

Often, anglers catch bullhead catfish accidentally. In most states, bullhead catfish are considered non-game fish and can be targeted using various alternative fishing methods, from bow-fishing to snagging. Generally, you can find bullheads in either fresh, brackish, and low-oxygenated waters. There are four common types of bullhead catfish found in North America: black, brown, yellow, and flat bullheads. Here’s a list of qualities that set bullheads apart from the other catfish species:

  • Colors vary between bullheads, ranging from yellow, brown, and black
  • Mottled dark skin on its side for browns and flats
  • Pigmented barbels
  • Squared tail fin

Additionally, bullheads are the smallest catfish species in North America, with the largest bullhead weighing eight pounds.

Common Saltwater Catfish Species

Did you know many catfish species live in saltwater? However, only two saltwater catfish species are the most sought-after gafftopsail and hardhead catfish.

Gafftopsail Catfish

Gafftopsail catfish against a white background.

Gafftopsail catfish are also known as sail cats. They get their name from their tall, sail-like dorsal fin. However, although their dorsal fin looks majestic at first glance, you want to stray away from touching it. Specifically, just like freshwater catfish, they have three venomous spines on their dorsal and pectoral fins.

In addition to their sharp spines, a thick toxic slime coats their entire bodies. This slimy residue from their bodies gets all over the place, making them an unfavorable catch for most anglers. For instance, like bullheads, gafftopsails are often caught accidentally by anglers, with the largest one weighing 10 pounds. Here is a list of distinguishing features of a gafftopsail catfish:

  • Scaleless, bluish-green back skin
  • Silver-white belly skin
  • Tall, sail-like dorsal fin
  • Flattened, elongated barbels
  • Forked tail fin

Hardhead Catfish

A hardhead catfish against a white background.

The hardhead catfish get their name from the rock-like bony plate on the top of their head. In addition to their solid heads, anglers should be wary of a hardhead’s serrated spines. Often, hardheads are referred to as trash fish by most anglers and aren’t considered good eating.

Additionally, anglers can locate hardheads along the southeast U.S. Atlantic coast and Gulf coast. Many anglers rarely target hardheads; however, these fish are notorious for stealing your bait and ending up at the end of your hook. Currently, the largest hardhead recorded by the IGFA weighs four pounds and 11 ounces. Here are the characteristics of a hardhead catfish:

  • Scaleless, grayish-green back skin
  • White to yellowish belly
  • Elongated body
  • Moderately flat head
  • Broadly arced upper jaw
  • Forked tail fin

Stay Out of Trouble With the DNR!

Remember, there is more to identifying each catfish species than just looking at their colors. To correctly identify a catfish, you need to examine the shape of its dorsal and tail fin, the form of its body and head, and its jawline.

Note, most states have different restrictions and regulations for each catfish species. So, it’s essential to know how to tell them apart to stay out of trouble with your local DNR agents.

Do you have any questions on how to identify catfish? Let us know in the comments below. Did you enjoy this article? Consider sharing it with your fishing buddies.