Habitat characteristics of leatherside chub (Gila copei) at two spatial scales

Populations of leatherside chub (Gila copei), a little-known species native to the eastern Great Basin, have declined and their distribution has becom e fragmented. To determine habitat requirements and possible factors respon sible for population decline, we quantified macrohabitats and microhabitats occupied by leatherside chub. Macrohabitat was surveyed at 59 sites in the Sevier River drainage of south central Utah, and microhabitats occupied by leatherside chub were measured at 3 locations spanning the species latitud inal range. Characteristics of points in the stream where leatherside chub occurred were compared to points where they did not occur. Abundance of bro wn trout (Salmo trutta) and elevation were weakly negatively correlated wit h leatherside chub distribution on a macrohabitat scale. Microhabitats occu pied by leatherside chub were characterized by low water velocities (2.5-45 cm sec(-1)), intermediate water depths (25-65 cm), and low percent composi tion of sand-silt or gravel substrates. This study suggests that the presen ce of introduced brown trout may have led to the decline of leatherside chu b.