insects. Etheostoma akatulo occurs in slow to moderate current over sand and fine gravel at depths of 10–50 cm, typically just downstream of riffles, in runs, or along margins of pools. During spawning Etheostoma akatulo males and females have been seen occupying different microhabitats. Substrate dominated by gravel were occupied by lone males and spawning pairs, whereas most lone females were found over a sand-dominant substrate. After the spawning period, Bluemask Darters move to sandy substrates in low-velocity areas of intermediate depth. Life history The life cycle of Etheostoma akatulo has been compared to that of Etheostoma stigmaeum. Etheostoma akatulo, before it was formally described, was once considered a subspecies of Etheostoma stigmaeum. E. stigmaeum is known to lay its eggs in gravelly areas and after they have been laid, it covers them with the gravel. Etheostoma akatulo is believed to demonstrate the same egg laying behavior. E. akatulo can live to be 39 months old. They show the highest amount of growth during the first year of life but do not reach sexual maturity until year two. Management Etheostoma akatulo was listed as a federally endangered species in 1993. Existing and potential threats to continued survival of the species include habitat destruction from gravel dredging, which has already eliminated habitat once occupied by the species in Collins River; pesticides in runoff or groundwater from plant nurseries; siltation from gravel mining, agricultural runoff, or land-disturbing activities; and acid mine drainage from headwater streams. The most significant factor contributing to the bluemask darter's decline was likely the building of the Great Falls Dam. The reservoir impounded by the dam flooded over 80 kilometers of possible bluemask darter habitat and isolated the tributary populations from each other. Because of the isolation, the genetic viability over a long period of time is questionable for the species. One of the current plans for management is the reintroduction of Etheostoma akatulo to the Calfkiller River. Because of gravel dredging the substrate in Calfkiller River is not ideal so first they are making new sand and gravel substrates. Then, the reintroduction of the fish will begin. References Etheostoma Fish described in 2009 Natural history of Tennessee ESA endangered species