During the onslaught of heavy rains on Sanibel, some remarkable things can be seen. Everything from frogs, crayfish and fish emerge to take advantage of the sudden abundance of fresh rainwater.
Perhaps you have seen a walking catfish? The invasive fish from Southeast Asia is — unfortunately — very common, where it is often seen “walking” from waterbody to waterbody in residential and protected areas. Sanibel-Captiva Conservation Foundation Wildlife & Habitat Management Director Chris Lechowicz recently videoed one moving across a residential driveway after a heavy rain event.
The walking catfish has been documented on the island since the 1970s, although it was first documented in Broward County in the 1960s. It was a common aquarium fish that escaped from fish farms and was released from aquarists who no longer wanted them — and they quickly spread. This is the only catfish, which reaches 20 inches in length, found in the freshwater bodies on Sanibel.
The species “walks” or wiggles across the landscape by using its pectoral fins to elevate its body above the ground and twist like a snake to move forward. They use a specialized gill to breathe air while not in the water. Walking catfish are distinctive from others: They have an elongated dorsal fin that runs almost the whole length of the body. The fish also produce a distinct sound while on land that sounds like “clicking.” Like other fish species in the taxonomic order Siluriformes (catfish), it has barbels — whiskers — around the mouth for feeling for food along the bottom of murky waterbodies. Walking catfish are mostly brown in color; however, white individuals — albino — are sometimes seen.
These invasives spread to new areas quickly and are considered an aquaculture nuisance because they infiltrate manmade ponds used to reproduce fish. They quickly dominate the ponds by eating all the fish and are nearly impossible to eradicate.
To watch Lechowicz’s video, visit https://www.youtube.com/watch?v=bhT1NLNoz4Q.