silver chub, brook chub, horneyhead chub, horned dace
The creek chub is a small minnow that has a greenish- brown to dark olive back with a silver white belly (Wikipedia, 2013). The sides can have a greenish purple reflection (MDC, 2013). It differs in coloration from light brown to dark green. It is about 4-10 inches in length and about 1 inch wide (Bosanko, 2013). This fish may be confused with a largemouth bass because of the big mouth and similar dark green coloration; however largemouth bass have two dorsal fins whereas the creek chub has only one. It is important to note that creek chub differ in their coloration above their lateral stripe from pale brown to dark green.
This fish has a black spot at both the front of the dorsal fin and the base of the tail fin as well as a lateral stripe separating the darker top from the whiter belly (Wikipedia, 2013).
The creek chub is a school fish that is known to school from birth to late adulthood; initially hesitant to travel away from its known area. As it grows the creek chub will travel away from its known territory and engage in aggressive behavior with other members of the species. It will enlarge its mouth and widen its fins as well as head butt others of the species to protect its territory (Wikipedia, 2013).
The creek chub eats mostly insects but also eats crayfish, smaller fish, worms, and mollusks; carnivorous. Adults have been documented to never feed before 1100 hours. This is most likely due to the fact that fish often do not leave their shelters until the temperature has reached a daily maximum (Wikipedia, 2013).
The creek chub spawns in Missouri from early April to late May. Males will construct and defend a spawning nest made of gravel with an oval pit at the downstream end. This fish requires flowing water and gravel for spawning. Individuals can live up to 8 years (MDC, 2013). Females will release around 25-30 eggs each fertilization cycle. During the breeding season, the males will grow small bumps on their heads called tubercles. These are keratin-based bumps which are used in ritualized combat to ward off intruding males on nesting sites (Wikipedia, 2013).
This is the largest Missouri native minnow and is most often found in small headwater creeks. When the creek dries in arid weather, the chub survives in isolated pools. The creek chub does not thrive in streams with continuous flow due to competition from other fish (MDC, 2013).
It is found in the U.S. east of the Rocky Mountains, and is one of the most common and wide ranging minnows in Missouri (Bosanko, 2013).
A previous study has observed that creek chub were limited in the prey they consumed by their gape, which is their mouth size when fully open. There were four distinct stages of the creek chub where a size difference in prey consumed was observed. <8.0 mm Standard Length (SL), 8.0-9.6 mm SL, 9.7-14.1 mm SL, and > 14.1 mm SL. For the fish in the <0.8 mm and 9.6-14.1 mm SL range the maximum prey size was limited by the fishes gape. The fish in the 8.0-9.6 mm SL range had a maximum prey size that was smaller than what was predicted by the fishes gape. After the 14.1 mm SL range the gape was no longer a limiting factor. It was concluded that creek chub were limited in the size of prey they consumed due to their gape. Also creek chub ate larger prey as they increased in size. This study did not show if creek chub changed their diet as they grew but rather that their prey size increased as they grew (Ward, 2008).
Notes: The creek chub is known to rise like a trout to a fly or other small artificial lure (MDC, 2013). Its characteristic habitat is a shallow, slow running creek abundant with insects and crayfish. This fish is preyed upon by birds and other larger fish (Wikipedia, 2013).
Creek Chub Drawing:
Bosanko D. Fish of Missouri Field Guide. Cambridge, MN: Adventure Publications; 2013.
Missouri Department of Conservation. Creek Chub. MDCOnline. http://mdc.mo.gov/discover-nature/field-guide/creek-chub. Published 2013. Accessed November 8, 2013.
Ward SA, Coburn MM. Stepwise Increases in Maximum Prey Size of Larval Creek Chubs, Semotilus Atromaculatus, in an Urbanized Ohio Stream. Northeastern Naturalist. 2008; 15.3: 349-62.
Wikimedia Foundation. Semotilus Atromaculatus. Wikipedia. http://en.wikipedia.org/wiki/Semotilus_atromaculatus. Published October 31, 2013. Accessed November 8, 2013.