The trout-perch, Percopsis omiscomaycus, is an interesting little fish that has been introduced to Willard Bay Reservoir, but is not native to Utah. The trout-perch is different from most other fish species because it has spiny fin rays, like a perch, but it also has an adipose fin (a small fleshy fin behind the dorsal fin), like a trout. The trout-perch is native to the Columbia River system.
Trout-perch spawn throughout the summer and primarily eat invertebrates and small fishes. The status of the trout-perch population in Willard Bay Reservoir is currently unknown. If the population is doing well, the trout-perch is likely an important forage fish for the many species of sport fish in the reservoir.