Overview
The southern redbelly dace is an energetic, schooling fish that inhabits clear, cool waters in small to medium streams in the Mississippi, Ohio and Missouri river drainages. Their populations are widely scattered across the Great Plains, but most of their population range occurs to the east. They are found from southern Minnesota and Wisconsin in the north, to Arkansas, southern Mississippi and Alabama in the south, and from western Pennsylvania in the east to Colorado, New Mexico, and Oklahoma in the west. While they can be common, or even abundant, where there is a high quality and quantity of their preferred habitat, populations of southern redbelly dace throughout all but the center of its main range appear to be declining. Populations are reduced and isolated from each other and from the main range of this species to the east.
Southern redbelly dace are critically imperiled in several states including Colorado, South Dakota, New Mexico, Pennsylvania and Michigan. Their populations are imperiled in Kansas, Mississippi and West Virginia, and classified as vulnerable in Indiana and Alabama. They are restricted to relatively small regions where the cold water from springs and headwater streams creates similar conditions to the last glacial retreat from the Great Plains Region. Some habitat changes are consequences of natural climatic shift to warmer and drier conditions, but human activities have accelerated this natural reduction of available habitat. Potential threats to southern redbelly dace include reduction of water flows, decreased water quality, physical modification of streams, introduction of non-native species, collection for bait or aquarium fish and disruption of genetic exchange.
Southern redbelly dace are prey to many different species, including piscivorous birds, carnivorous aquatic insects, snakes, turtles, bullfrogs, salamanders, mink, martens and raccoons, as well as predatory fish. In some parts of their range, this species is numerous and abundant, but many populations have become restricted and isolated. Southern redbelly dace are typically part of a well-balanced fish community of small fishes that can share resources in a confined habitat. This may include a small number of smaller predatory fish like bass, sunfish or trout, but when larger sport fish of these species are introduced to confined habitats, they can negatively affect dace populations.
Southern redbelly dace populations may become extirpated where high quality stream habitat is disturbed by channelization, construction of ditches, dams and removal of trees in riparian riparian
Definition of riparian habitat or riparian areas.
Learn more about riparian zones. The optimal habitat for dace is clear, cool streams which are fed by groundwater with heavy vegetation for cover and gravel or sand substrate. Permanent sources of cool, clear groundwater are highly desired resources for human uses like irrigation or municipal water supplies. In many places, spring seeps have been dammed to form lakes which are inhospitable to southern redbelly dace. Stream modifications can also create barriers to migration and dispersal, which leads to more isolation and fragmentation of populations.
Land uses in riparian zones like crop production, cattle grazing, lumbering, mining and construction can lead to erosion and siltation that increases water turbidity. Southern redbelly dace require clean gravel substrates for reproduction and feeding. They rely on their sight to feed and recognize brilliant color patterns of potential mates during spawning. Multiple stressors from human activities, combined with extreme disturbance events like long-term drought, may severely deplete or extirpate these already highly fragmented populations. Conservation efforts include habitat restoration and protection, monitoring vulnerable populations, limiting harvest and restocking and reintroducing southern redbelly dace where appropriate. Some examples of improving and protecting habitats include restoring natural stream ecosystems, protecting spring-fed streams, preventing erosion by maintaining riparian buffers and removing non-native predatory species. All of these actions can help protect and increase southern redbelly dace populations throughout their range.
Scientific Name
Identification Numbers
Characteristics
Habitat
Southern redbelly dace are found in narrow meandering headwater streams and upland creeks usually that are fed by springs or groundwater seepage. They prefer clear cool streams with riffles and slow flowing pools, as well as silt-free, sand and gravel bottoms. They use undercut banks, woody debris and vegetation mats for cover. Occasionally they are found in faster currents in riffles of larger streams when spawning or feeding on algae-covered rocks. This species does not occur in ponds or lakes unless they are connected to a river, stream or spring. Clear water with little or no turbidity is extremely important for these sight-feeding fish to find food as well as mates.
Land on which the natural dominant plant forms are grasses and forbs.
A natural body of running water.
Areas where ground water meets the surface.
Food
Southern redbelly dace are opportunistic, sight-feeding herbivores or omnivores. Feeding occurs more often during the daytime when visibility is better than at night. They feed by sucking or nipping small particles of algae, detritus and small invertebrates from rocks. They have a long intestine and fine throat teeth for feeding.
Behavior
The southern redbelly dace is a schooling species that does not display territorial behavior or defend nests and feeding areas. Adults are usually observed in tight schools of mixed sizes and ages. These fish respond to predators by forming a dense shoal in mid-water instead of scattering for cover and hiding individually. These shoals increase protection from predators but this behavior makes them especially vulnerable to human collectors with nets.
Physical Characteristics
Southern redbelly dace are a type of minnow, a small torpedo-shaped fish. Unlike other dace species, female southern redbelly dace are slightly smaller on average than males.
Measurements
Length: 3 in (75 mm)
Southern redbelly dace have very small scales and one or two horizontal black bands along their sides, with iridescent silvery areas above the main lateral band. The top dark band starts at the edge of the gills and turns into a series of spots at the base of the tail. The lower band encircles the snout and ends at the tail. During the spring, males turn bright red on their bellies, which inspires their name. They also develop a yellow band between the black side bands which become darker and more defined. This pattern is obvious even before spawning, but becomes especially bright during breeding seasons, and is retained to some extent throughout the entire year. Females usually do not display much red and yellow on their sides. Males develop small bumps called, pearl organs or breeding tubercles, in a unique pattern on their fins, sides, in front of the pectoral fins and above the anal fin during breeding season as well.
Life Cycle
Like most species of freshwater fish, southern redbelly dace begin life as an egg. An embryo develops inside the egg which eventually hatches into a larval fish that can acquire its own food. They grow into juvenile fish sometimes called fry. At this stage they look like small adults, and although their coloration may be different, they have all their normal fins and internal organs. Fish are considered adults when they are reproductively mature. For most southern redbelly dace, this occurs during June in the year after their birth, when fish are approximately 2 inches (50 millimeters). Fish continue to reproduce at two and three years, and few if any individuals survive to four years.
The southern redbelly dace is a short-lived species. These fish become sexually mature around age 1 and few if any individuals survive to four years.
Spawning season for the southern redbelly dace occurs in April and May for most mature fish. Younger fish may continue to spawn in shorter and less intensive episodes well into July in some populations. During spawning, large groups of brilliantly colored males congregate over the spawning area, usually a riffle or gravel bed, while females stage downstream. Single females dart up into the spawning area where two or more males will cradle the female with their pectoral fins. The numerous breeding tubercles that develop on their large fins helps males maintain contact with the female and press her against the gravel substrate. The spawning fish vibrate vigorously, and eggs are buried in the sand or gravel as they are fertilized. This act only lasts a few seconds, but it can be repeated many times per hour. Female southern redbelly dace can produce between 500 and 1,000 eggs per year.
Similar Species
The southern redbelly dace is closely related to the northern redbelly dace (Chrosomus eos). Generally, the two species distributions do not coincide, but there are a few places where their ranges overlap, and they coexist. Even where they are found together, it is easy to distinguish these species. The southern redbelly dace is larger and usually has more prominent, or darker and thicker, black lateral bands while the northern redbelly dace is usually smaller and has more slender black lateral bands. In the spring when males are fully colored, the entire underside of the male southern redbelly dace often shows bright red, while the belly of northern redbelly dace remains white. Additionally, the snout is longer and the mouth more horizontal in southern redbelly dace.
Geography
The southern redbelly dace is found entirely within the boundaries of the United States and they are widely distributed throughout the Mississippi, Ohio and Missouri river drainages. They range from southern Minnesota and Wisconsin in the north, to Arkansas, southern Mississippi, and Alabama in the south, and from western Pennsylvania in the east to Colorado, New Mexico, and Oklahoma in the west. Most of their populations occur in the midwest to the south, which encompasses much of the Mississippi and Missouri river drainages. In the western part of their range, southern redbelly dace are restricted to rather small, scattered populations near the headwaters of tributaries of larger rivers like the Missouri, Kansas and Arkansas rivers.