Mean Mouth Bass

Angler interest in the naturally occurring smallmouth bass / spotted bass hybrid has heightened recently due to an article in BASSMASTER magazine concerning the documentation of a new state record in Missouri. The Kentucky Department of Fish and Wildlife Resources would like to address this hybrid and its implications to anglers.

A hybrid occurs when one fish species spawns with a different, but closely related species. Hybrids can occur naturally or can also be intentionally produced in a hatchery. Naturally occurring hybrids are common among sunfish species such as bluegill and green sunfish. A common hatchery produced hybrid is the hybrid striped bass (white bass / striped bass). Hybrids of black bass species have been documented in the United States for some time. Early research dealt with hatchery production of a largemouth bass / smallmouth bass hybrid. This was the original “mean-mouth” bass.

The largemouth / smallmouth bass hybrid is not common in nature due to differences in both habitat preferences and spawning times. However, smallmouth bass and spotted bass can overlap in habitat use and spawning times. Generally, there are subtle behavioral differences associated with spawning that prevent or minimize hybridization. Although the smallmouth bass / spotted bass hybrid is not the original “mean-mouth” bass, it has acquired this name over time.

The smallmouth / spotted bass hybrid has been found at very low densities in several states including Missouri and Georgia. Kentucky has not documented the presence of this hybrid. This does not mean it doesn’t exist; it just means the Department has not collected any specimens and genetically tested them.
The Department has now begun to examine for the presence of this fish in Kentucky.

A limited number of anglers have been asked to save some fish that they consider to be “mean-mouth” bass. We ask that only these selected anglers provide the fish so that we do not receive more fish than we can process. Collected fish will be sent to a lab for genetic testing.

Most anglers will probably never encounter this hybrid due to its low numbers. An “odd” looking smallmouth or spotted bass may not necessarily be a hybrid. Presently there is no size-limit regulation addressing hybrid black bass; however the six fish creel limit will apply. Wildlife and Boating officers will exercise their discretion when they inspect these fish in angler’s creel. To prevent any problems, anglers should obey the smallmouth bass size limit (the most restrictive) when they catch a “mean-mouth”. Check CVS Ad on WeeklyAds2.

By Jeff Ross Kentucky Department of Fish and Wildlife Resources