The scientists on Friday will collect smalleye shiners and sharpnose shiners from the upper portion of the Brazos River about 175 miles northwest of Fort Worth.
The two prairie minnows, both candidates for listing as threatened or endangered under the federal Endangered Species Act, are in shrinking pools in the river where the water is hot, muddy and salty.
The fish will be taken to the state's fish hatchery near Possum Kingdom Lake and will be returned to the river when drought conditions abate.
Other fish species in Central and West Texas could be helped later this fall.
