Examination of the Current Oklahoma State Record Smallmouth Buffalo

Abstract

Smallmouth Buffalo (Ictiobus bubalus) is found predominately in eastern Oklahoma
and recognized as a non-game species by the Oklahoma Department of Wildlife Conservation. The designation of non-game allows the species to be recreationally caught or harvested using any legal method and without limits. We examined the current state record (restricted division: allowing recreational harvest with no restriction) Smallmouth Buffalo caught using rod and reel on May 3, 2019 from Broken Bow Reservoir. The lapilli otoliths were removed from this specimen to estimate age, back calculate length-at-age (growth rates), and back calculate spawning year. The final estimated age of this fish was 62 years old. The growth curve using back-calculated length-at-age suggested this Smallmouth Buffalo initially grew rapidly (80% of total length within first 17 years), but the growth increments constricted with increasing age. Based on the estimated age of this fish, the state record Smallmouth Buffalo was spawned in 1957, indicating this fish was spawned prior to impoundment of Broken Bow Reservoir. Further, the hatch year of this fish corresponds with flooding, after a prolonged drought, demonstrating the importance of river flow to successful spawning of this species. Although this study is limited to a single specimen, it improves our knowledge of a long-lived, understudied species in Oklahoma.