The subspecies of orangebelly darter, a fish found in Oklahoma's Blue River drainage, was recently elevated to a full species by the University of Oklahoma's William Matthews and University of New Mexico's Thomas Turner.
Blue River orangebelly darters, male (A, C) and female (B). (Nick Lang)
The newly described Blue River orangebelly darter can be distinguished from other orangebelly varieties by mitochondrial DNA, scale counts, subtle differences in coloration, and dimensions of the head. Even so, both fish are relatively small and colorful fish that prefer rocky riffles and rapids. During the spawning season, males develop bright orange and blue fins.
This species has only been documented in the Blue River drainage of southcentral Oklahoma. It appears to be most common in spring-fed and rocky portions of the upper drainages, as well as in some small tributaries of the river.
Read the Copeia journal article that redescribed and recognized the darter as a full species