Date:10/7/24
Happy Monday, everybody! Today's fish of the day is the hornyhead chub!
The hornyhead chub, named for their pronounced tuberacles (bony projections) in spawning males, scientific name Nocomis biguttatus. This fish is a kind of minnow found exclusively in North American freshwater. Living in a range from Wyoming to New York, and as far north as North Dakota to Southern Arkansas, although they can occasionally be found outside of their normal range in the Colorado river and as far South as Georgia. This fish lives primarily along the Ohio, Kentucky, and Mississippi rivers, branching off into smaller creeks. Within these creeks the fish prefers to live along rock beds preferring calm clear waters, with a tolerance for darker waters only if there is a lack of turbidity. Young live exclusively near vegetation, using it as a hiding place from predators, but adult populations are entirely unaffected by its presence or lack thereof.
Despite being a minnow, a family often thought to be some of the lower rungs of the aquatic food-web, this fish has no major predators outside of local large omnivore or carnivore fish in certain areas. Yet, despite this they are reducing from their natural ranges and are practically endangered in Wyoming, Pennsylvania, and Kansas for reasons we aren't fully sure of. These fish are essential in these food webs due to their nesting sites sticking around years after the inhabitants have passed, being used by numerous other animals after them. Conservation efforts have taken place in affected areas, preventing excessive human harvesting for bait. On a global scale however, they are of least concern.
The hornyhead chub's diet is wide, as an opportunistic omnivore. Found foraging in both day and night, they are far more active when the sun is up, as they rely almost entirely on sight, possibly the same reason for their prevalence in clear stiller waters.. The juvenile fish forage for smaller fish, insect larvae, small crustaceans, and freshwater plankton, while the adult hornyhead chub's prey on larger fish, insect larvae, snails, worms, clams, and larger crustaceans. This diet allows them to reach a size of as large as 12 inches, with an average of 8.5 inches, rather large for a minnow species.
The life cycle of the hornyhead chub is similar to that of many others. After hatching from their eggs, these fish will live 6 months as fry, before being a juvenile for the next year. Then, at 2-3 years of age these fish sexually mature. This is when the male will build a large mound of pebbles into a nest, which they will spend the entire breeding season and after guarding. These males guard the nest from other male hornyhead chubs, but do not guard from other fish, leading to several cases of hybridization of species, as these nests are a safe area to lay other species eggs in. Even within their own species, females will lay eggs across multiple nests, ensuring diversity. These fish live only 3-4 years, and so they can live for only 1 or 2 breeding season, but are almost certain assured their legacy will live on, as the predation of hornyhead chubs is small, and fertilized eggs are covered by gravel before guarding, such the predators can not find them before hatching either.
That's the hornyhead chub, everybody! Have a wonderful Monday, and have a good week ahead!