Habitat use by fishes of the San Bernardino National Wildlife Refuge

Abstract

I quantified microhabitat conditions used by Yaqui chub (Gila purpurea), Yaqui topminnow (Poeciliopsis occidentalis sonoriensis), and beautiful shiner (Cyprinella lutrensis) on the San Bernardino National Wildlife Refuge, Arizona. Different species and different lifestages used different microhabitats. Smaller fish selected shallower water than adults. Yaqui topminnow and Yaqui chub showed seasonal variation in microhabitats used. Yaqui topminnows were found closer to cover when in the presence of beautiful shiners. Close proximity to cover may indicate a negative interaction. Yaqui chubs did not use microhabitats differently when in the presence of the other two species. Microhabitats used by Yaqui chubs in the ponds and Leslie Creek did not differ. Yaqui chub preferred pools with little or no flow. Management of aquatic environments on the refuge should focus on vegetative thinning. Stocking of beautiful shiner with Yaqui topminnow should be postponed until further research is conducted on the interactions between the two species.