Pond Boss Forums INTRO Questions & Observations Mean Mouth Bass?

BillD. Keep us informed if you see some young bass that do to not look like regular smallmouth. The SMB that you have will likely produce young bass. It will be your job to figure out if they are pure SMB or hybrids. Here is some information about the SMBXLMB hybrid (aka Mean mouth) and how the name was coined. Info from In-Fisherman.

Meanmouth Bass: In the mid-1960s, Dr. William Childers and colleagues at the Illinois Natural History Survey began studies of centrarchid (sunfish family) hybrids. In the lab, they produced some oddballs—crosses of largemouth bass with warmouth, green sunfish, and bluegill. Crosses with crappie and rock bass failed.

The researchers noted that different black bass species didn’t hybridize when stocked in ponds with members of another species (i.e., all males of one species with all females of another). But fertilizing largemouth eggs with smallmouth sperm produced viable offspring that reproduced among themselves and with both parental species. Cody Note: Some think the two did not cross because each had a slightly different spawning period temperature requirement, thus both were not ready at the same time.

The term “meanmouth bass” was born when Childers observed a school of largemouth-smallmouths attacking a female swimmer. “The bass leaped from the water and struck her on the head and chest,” he wrote, “and drove her from the pond.” On another occasion, he watched meanmouths attack a dog that ventured into shallow water.

Though indications of hybrid vigor were evident in aggressiveness and fast growth, high mortality and low reproductive rates for the hybrids led to a halt of this investigation in the 1980s. Childers cautioned that backcrossing of hybrids with parental species would be harmful, since gene flow between the species would reduce the fitness of populations as maladaptive genes were introduced. Over 30 years ago, he urged caution in mixing bass subspecies and even geographically separated populations of fish of the same species.

In nearly all cases of hybridization outside the lab, smallmouth have been involved. Geneticist Dr. Dave Philipp, colleague of the late Dr. Childers, noted that fertilization of largemouth bass eggs with smallmouth sperm resulted in more successful crosses than the reciprocal cross (largemouth male and female smallie). The aggressive male smallmouth bass may be an instigator when introduced into waters outside its natural range where spawning sites are limited, or in altered habitats such as reservoirs.

When smallies were added to newly constructed Squaw Creek Reservoir in Texas, they soon hybridized and backcrossed with both northern and Florida subspecies of largemouths that were already in the impoundment. In 1993, Rich Fry caught an 8-pound 3-ounce bass from a Pennsylvania mine pit that was genetically identified as a first-generation hybrid of a largemouth and a smallmouth bass.