Percina nigrofasciata

Introduction

The following article is a description of a monitoring plan for the blackbanded darter, Percina nigrofasciata, written for the Ichthyology course at the University of Tennessee. The blackbanded darter is a small fish belonging to the Percina genus in the Percidae family. The body of the fish is variable and is influenced by the surrounding habitat. The blackbanded darter will be a light color if it is found along a sandy substrate. The darters that have a dark color are usually found around leaf litter, sticks, and aquatic vegetation. Breeding males have a greenish blue wash over their body and the head is brownish gold color.^[1] The blackbanded darter can be confused with the dusky darter (Percina sciera). This species of darter was described by Agassiz in 1854 and there has been little research done on this species. The geographical range of the blackbanded darter can be found in the Gulf and Atlantic slope drainage system in southeastern United States from Louisiana to South Carolina. It is one of the 324 fish species found in Tennessee.^[2] It prefers sandy or gravel substrates in medium sized rivers. Their diet consist of midge, blackfly, mayfly, and caddisfly larvae that are found in the water.^[3] This species of Percina is an early spawner in which they spawn in May and June. Currently, there is little management for this species, and is currently not listed on the endangered species list or the threatened species list. However, a specific management plan might be considered to ensure the species survives. This paper will discuss the in depth geographic distribution, ecology, life history, management, and recommendation for the Blackbanded Darter.

Geographic distribution

Percina nigrofasciata is a freshwater species of fish that is can many different rivers systems in the United States. They are found in the Atlantic draining systems as well as the Gulf slope draining system in southeastern United States (South Carolina, Tennessee, Georgia, Florida, Mississippi, Alabama, and Louisiana).^[4] They can be found in the Santee River in South Carolina all the way over to the western part of the Mississippi tributaries in Louisiana Their range goes as far south to far south to Lake Okeechobee in Central Florida. Percina nigrofasciata is the most common darter throughout its range. The blackbanded darter are absent in the Satilla River and the St. Mary’s river in southeast Georgia and northern Florida.^[5] In the Altamaha River which is located in Central and South Georgia, the blackbanded darter is considered rare.

Ecology

The blackbanded darter is found in headwaters to medium sized rivers over gravel and sand.^[6] In the Coastal Plains, they are found often over mud areas.^[7] The color of the fish is related to the surrounding habitat they are in. Percina nigrofasciata that is found in sand areas will have a lighter color. Blackbanded darters that are found around dark gravel, leaf detritus, etc. will have a darker color. Percina nigrofasciata can be similar to the Dusky Darter (P. Sciera).^[8] Blackbanded darters tend to live in intermediate microhabitat that has more erosional substrata and greater variety of depth.^[5] Percina nigrofasciata are insectivores and feed on mayflies, midge, blackfly, caddisfly, or anything that is no larger than five millimeters.^[9] The primary predator for the blackbanded darter is stonecats, largemouth bass, and other larger freshwater fish species. Human induced changes such as pollution, sewer drainage are just some of examples that may cause a negative impact of the abundance of the fish, and could reduce the population of the blackbanded darter.

Life History

Blackbanded darter is early spawner and happens from between February to June. Spawning occurs in sandy bottoms around a stream channel. The male approaches a female from the rear. Once on the female, he mounts himself to her and beats her with his pelvic fin. The average clutch size for the blackbanded darter depends on its location. In Florida, a clutch size range from 4 to 73 eggs, while in Alabama, the range is from 38 to 250 eggs. ^[10] In Alabama, the sex ratio of the eggs favors male over females.^[11] After the eggs are laid, there is no parental care over the eggs. The life span of the blackbanded darter is estimated to be around three to four years. The life history of Percina nigrofasciata depends on geographic variation in environmental condition such as photoperiod and water temperature. Pollution and siltation can cause temperature change of the water which will affect when the darter will spawn.

management

Percina nigrofasciata is not endangered or threatened in its range. They are listed as least concern because there are large number of the fish, it’s just nobody there really isn't any evaluation on them to know the exact number of the species. ^[12] In many areas of the southeastern United States where they inhabit, they are most abundant fish in river, but the Blackbanded darter is rare in the Altamaha River which is located in the state of Georgia. Populations of the blackbanded darter are at a good level in location where they are found in the southeastern United States. Currently, there is no management plans for Percina nigrofasciata probably because it is not federally listed as endangered or threatened. ^[6] Another reason that there is no management plans, is because there hasn’t been a lot of research on the fish to know the exact population number of the darter to really tell if they need to be protected and managed. Currently, no agencies or nongovernmental groups are trying to protect this species, because of its abundance. Over the years, if there is no management for Percina nigrofasciata, habitat destruction as well as invasive species may reduce the species. With this said, there is so far no conservation or refugee easement going on to help this species out.

Recommendation

To monitor and manage the species, having a good estimate on the abundance of the species in their native range is needed. Sampling methods that can be used to estimate their numbers is sand kicking and then use a gill net. This is the perfect method, because Percina nigrofasciata are found around sand so kicking the bottom going to the net can trap the fish and the researchers can easy count how many fish there are. Electroshocking would be another methods that may be used to manage the blackbanded darter species. Electroshocking provides one of the best ways to obtain abundance estimates for small nongame fishes like the blackbanded darter. ^[13] Water testing may be another way to manage for blackbanded darters. This is important, because for spawning, the fish has to have a certain water temperature to spawn. In order to increase the species population, the water temperature needs to be right for the fish to spawn and lay the eggs. This will increase the chance of more and more eggs to hatch so more of these darters will be swimming the freshwater rivers. Some watershed areas in the southeastern United States where they inhabit should be set aside for future protection of species and other coexisting species that live with the blackbanded darter. Land areas around rivers where the blackbanded darter should also be set aside, because they like vegetation and leaf debris as hiding places against predators. If an invasive species becomes a threat to blackbanded the darter, the wildlife agencies should step in and try and remove that species without reducing the impact of the presence of the blackbanded darter.

References