Kentucky is home to many wonderful and diverse freshwater fish. In fact, only Tennessee and Alabama have more freshwater fish than the 244 species found in Kentucky. So even though we don’t rehabilitate fish here at Fox Run EEC I wanted to introduce you to them.
Fish are an important part of our wetlands. They are also a food source for many mammals, reptiles, and birds.
Fish play an important role in the nutrient cycle of their water habitats. The nutrients that fish have in their bodies as well as the nutrients they excrete help the overall ecosystem.
These nutrients affect all other life. They help plants and young fish grow by recycling nutrients and making them available to other organisms.
Fish Characteristics
How Do Fish Breathe Underwater?
Fish breathe differently than most other animals. They do not have lungs
Mammals including humans, reptiles, and birds get the oxygen they need from the air. We breathe it in through our nose, it flows down our trachea and into our lungs.
Fish also need oxygen to survive. Their bodies are designed to extract oxygen from the water. Fish take water into their mouths and it gets pushed over their gills. The gills are thin layers of skin.
The gills absorb the oxygen from the water, and it goes into their bloodstream. They expel carbon dioxide through their gills just like we expel it through our breath.
Do Fish Lay Eggs?
Some species of fish lay eggs, and some give birth to live young. As we discussed in Kentucky Snakes there are advantages and disadvantages to each.
The eggs provide a nutrient-rich safe place for the fry to grow. Eggs also give some individual protection to the babies.
However, there are a lot of predators that eat fish eggs.
Fish born live have to find their own sources of food and safe places to hide. Lots of other animals want to eat them too. Their advantage is that they can swim away.
Do Fish Hibernate?
Fish like our turtle friends are cold-blooded. During the winter when the water gets colder the fish’s metabolism slows down.
Fish don’t truly hibernate. They do not sleep but experience a slower resting time.
Some fish burrow into the mud at the bottom of a pond or river where it is warmer. They may also hide under rock outcroppings and sunken logs.
What is a Swim Bladder?
The swim bladder is an organ that bony fish use to control buoyancy. This helps them to remain still and conserve energy by floating in the water.
The swim bladder is filled with gasses like oxygen which is why fish don’t sink to the bottom.
The swim bladder can also act as a sound producer or receptor in some species like the freshwater Drum.
Fish that have cartilage skeletons like sharks don’t have a swim bladder and must maintain constant momentum. That’s why sharks swim all the time.
Kentucky Fish Species
Kentucky has a lot of interesting fish. Here are some of our favorites!
American Eel
Did you know that there were freshwater eels living in Kentucky? They spawn in the Atlantic Ocean and swim all the way here!
The female can lay up to 4 million buoyant, tiny eggs out in the ocean. She then dies. The young eels swim all the way up the Mississippi to the Ohio River and its tributaries.
Eels appear snake like, but they are fish that grow to five feet in length. They have a mucus layer which covers small scales and makes them look shiny.
A long dorsal fin runs down their backs.
Eels hunt at night for small aquatic organisms such as insects, crustaceans, and small fish.
Sadly, eel populations have been dramatically reduced due to habitat destruction. Dams built on rivers to control water flow make it difficult for them to migrate.
The American eel is a threatened species and considered high risk for extinction.
Bowfin
The bowfin is an ancient and fascinating fish. They are the only surviving species from the order Amiiformes that dates back to the Jurassic Period.
You may have heard bowfins referred to as dogfish or swamp trout. They are found throughout Kentucky and the eastern United States.
They are predators and stalk smaller fish and invertebrates at night.
They can tolerate low levels of oxygen in the water by using their swim bladder as a lung. They break come to the surface of the water and gulp air.
This allows them to extract oxygen from the air by a specialized organ called a pneumatic duct. The pneumatic duct is between the foregut and the swim bladder.
The bowfin has interesting mating habits. The males make nests from the roots of aquatic plants. The nest is big enough to hold the male fish.
The male who can turn a bright green color chases a female around till she joins him in the nest. She lays her eggs and then leaves.
The male may end up with up to 5000 eggs from several female fish in his nest. The male bowfin guards his eggs and young fry until they are a month old.
Closeup of the barbels on this channel catfish. US Fish and Wildlife photo
Catfish
Catfish are so named for the “whiskers” around the mouth. These barbels are sensory organs that help the catfish smell and taste.
They are bottom dwellers and are negatively buoyant. The flat shape of their head lets them shovel the mud at the bottom of rivers and ponds to find food.
They have an excellent sense of smell and hearing. They can also produce sounds and communicate with other catfish.
Catfish do not have scales like many fish. They have mucus-covered skin.
To make themselves less desirable to predators, catfish have sharp barbs on their dorsal and pectoral fins. Not only can they inflict wounds some are venomous.
Kentucky has 18 species of catfish. The smallest is the brindled madtom who only grows to five inches long. The largest is the blue catfish and they can reach five and a half feet and weigh 150 pounds.
Unusual albino alligator gar fish. Picture from US Department of Fish and Wildlife
Alligator Gar
Another ancient fish, there are four species of gar living in larger rivers and lakes throughout Kentucky. They are easily recognized by their long snouts and rows of sharp teeth.
Gars are often the top predator in their ecosystem. The Alligator gar can reach six feet long and weigh 100 pounds!
The longest specimen was ten feet long and weighed 300 pounds!
They have heavy duty ganoid scales. Ganoid scales are covered with a layer of dentine (like tooth enamel) and have serrated edges. They offer the gars good protection from predators.
Alligator Gar are listed as endangered in Kentucky due to habitat loss, construction of dams, and overfishing. This is sad because they play an important role in their ecosystems.
Gar control smaller fish populations as well as eating invasive carp. Plus they are very cool!
The Kentucky Department of Fish and Wildlife began reintroducing the alligator gar in 2009. Each year captive-bred fry are raised and released into the wild.
Currently, the fry are being released in rivers and large lakes in the counties of McCracken, Ballard, Livingston, Crittenden, Union, and Carlisle.
Minnows
Minnows or shiners are common with many different species. They live in streams, ponds, and lakes. They prefer to hang out in the warm shadows and are any easy fish to spot.
Many minnows are quite small at 3-4 inches however some grow to a foot in length.
Grass carp are an invasive species that eat native fish eggs and harm habitats.
Grass Carp
Grass carp are not a native species. They have been introduced into Kentucky waterways as a way to control plants in ponds.
Sadly, this is very short-sighted. As an invasive species, the grass carp are doing great damage to our native water ecosystems.
The grass carp ruins the natural food web of the pond. When they eat plants, they destroy hiding places for baby fish. They also eat the eggs of fish and frogs.
Carp are large fish and can grow to four feet long and 100 pounds.
Licking River Watershed Watch Group
Fox Run is part of the Licking River Watershed Watch which is run by the Kentucky Department of Water. Three times a year we take water samples from Fishing Creek to send to a local lab for testing. The test for things like E.coli and pollutants.
We also conduct tests for ph., temperature, and dissolved oxygen levels.
One of the instructors from the KY Dept. of Water leading a class at Fox Run EEC
Impact of Fishing
Fishing has a big impact on the economy. While sport fishing only accounts for 4% of fish caught it’s a 48-billion-dollar industry. That includes money for licenses, equipment, and other related items.
In addition, aquarium keeping is an eight billion industry the US Pet Fish and Aquarium states.
So fishing as a sport and for pets has a big economic impact. However, we can’t let that deter us from making sure we don’t destroy habitat and allow fish that ability to live their lives.
Author, Ame Vanorio, is the director of Fox Run Environmental Education Center.