Flame chub  (Hemitremia flammea)

Classified as Data Deficient (DD) on the IUCN Red List (1).

The only member of the genus Hemitremia (4), the flame chub is a small, robust minnow with a rounded body and head. The back and sides are a pale olive-green interspersed with flashes of gold and a dark stripe runs lengthways down the body to the base of the tail. A red spot adorns the base of the dorsal and tail fins (5). It is the breeding male that gives this striking fish its charismatic common name, due to its flame red lower body (5), although non-breeding males usually retain a little of this red colouration year-round (4). While the male is the more attractive of the sexes, it is the female that typically grows larger (4). The scientific name of the flame chub, Hemitremia, is derived from the Greek word meaning ‘half aperture’, referring to the dark stripe running the length of the body, while flammea means ‘flaming’ and refers to the bright red colours of the males during the breeding season (3). 

The flame chub is native to the United States, where it occurs in the Cumberland River System and the Tennessee River Drainage Basins in the states of Tennessee, Georgia and Alabama, and in Kelley Creek (in the Coosa River system) in north-eastern Alabama (2) (3) (5) (6). Historically, the flame chub was also found in Kentucky, but is now locally extinct in this area (7).    

The flame chub is a freshwater, demersal fish that has a preference for springs or small streams, but can also be found near the banks of larger streams. It is usually found in areas where there is plenty of aquatic vegetation (2) (5), such as watercress, swamp smartweed and small pondweed (8). The streams also need to have a relatively even channel bottom, but the substrate may vary from mud to rubble to bedrock (6).

Aquatic and terrestrial insects, including midges, larvae and tiny crustaceans, form the majority of the flame chub’s diet, but it is an opportunistic fish that will also take worms and snails.  It also feeds on filamentous algae, which form mats resembling wet wool in aquatic habitats (8).

Female flame chubs produce eggs from January until early June, with spawning commencing in winter and continuing into spring and early summer, usually with a peak in March (8). Although the flame chub is a highly productive breeder and can become abundant in the appropriate habitat, this species has a relatively short lifespan of just 1.5 to 2 years (2) (8).

Unfortunately, the flame chub’s preferred habitat is fragile and fast disappearing (5). Whilestream systems in Tennessee display the most varied collection of aquatic fauna in the country, the rapid growth of the human population combined with development and changes in land-use practices have significantly altered these important water systems (9).

Flame chub populations have become locally extinct in many areas because of the destruction of springs (5), as spreading urbanisation leaves springs buried below housing and industrial development, or logging and road construction result in springs becoming choked with sediment (9). Furthermore, excessive water withdrawal lowers the water table, preventing springs from flowing, and the water is being further degraded by toxic pesticides, fertilisers and other waste products (9).

Although previously listed as Rare, the IUCN has not assessed this species since 1996 and due to this lack of data are unable to confirm its current conservation status (1). The flame chub is listed as a Candidate Species under Section 4 of the Endangered Species Act (ESA) in the USA (10), meaning that although the species receives no statutory protection under the ESA, the formation of partnerships to conserve the species are encouraged (10). The flame chub is also listed as Endangered in the states of Georgia (11) and Tennessee, due to its fragile habitat (2).

View information on this species at the UNEP World Conservation Monitoring Centre.