Blackfish are one of the more uncommon species found in Kanuti National Wildlife Refuge waters. Blackfish females may spawn numerous times from May through August. Eggs will adhere to vegetation and hatch in a short 
time. Blackfish are easily caught in minnow traps and have become a valuable subsistence resource in many parts of Alaska during times of famine. It is one of only two known aquatic fish species that have modified their esophagus in order to breathe atmospheric oxygen. When oxygen levels drop throughout the winter, blackfish have been known to congregate near holes in the ice. This makes for easy capture. Blackfish will use this modified esophagus to gulp air, which allows them to migrate across very shallow water bodies.
