Things you need to know about invasive fish species



Back when I was a rookie in the art of angling, I heard some of my friends talk about invasive species. At the time, I had little to no idea what these meant and exactly what fish were catastrophic for the environment. In my narrowness, I couldn’t actually believe that introducing a new species in a habitat was a bad idea because resources were plentiful.

Unfortunately, the world has much changed over the last years, and that’s mostly because of the ever-growing needs of humans. Most of the fish you’re likely to buy from a store are farmed, which means that they inhabit an artificial habitat and are fed the food without having to ‘hunt’ for it as they would in the wild. As an angler, I find store-bought fish to be an appalling idea, but I have to be honest and say that not all people are either interested in the sport or have any place to go fish.

There’s a global database of invasive species you may want to check out if you’re interested in the topic. Most of the ones included in the list are insects and plants, but I’ve noticed some additions such as the Salmon trutta. If you are having trouble sifting through the data showcased on that particular site, I would recommend reading an article published on It deals with ten of the most damaging invasive species in the world.

The walking catfish is just one of such examples as it has managed to cause a damage of more than one million dollars. It mostly resides in ponds across Florida, but there might be high chances of it moving to different states in the future given that it is, above all, a resourceful fish that can feed on pretty much anything. On the one hand, it consumes the food that native species thrive on, and on the other, it even eats small fish and mollusks.


The Mosquitofish

A rather cute troublemaker is the mosquitofish. As its name suggests, this fish preys on mosquito larvae, and that’s why it’s so popular and acclaimed in Russia. It even has a monument dedicated to it in this country, if you can believe that. The problem is that mosquitofish don’t just eat the larvae mentioned above. They feed on anything from insects to zooplankton, so they might destroy the food sources for other species that have inhabited the ecosystem for hundreds and hundreds of years.

The largemouth bass, one of my personal friends, is another species you might know to be invasive. The legislation pertaining to targeting this fish is somewhat flexible because it is the main culprit for the decline of native frogs in the state of California.