Researcher: 'Two-Mouthed' Trout Caused by Injury, Not Genetics

Researcher: 'Two-Mouthed' Trout Caused by Injury, Not Genetics

By Algis J. Laukaitis

Source: underwatertimes

2/8/2006

Clarence Olberding of Lincoln thought he had the catch of the day when he hooked a trout with two mouths. But a Harvard University researcher who examined the severed fish head said the unusual deformity was caused by an injury and not a genetic mutation.

“Our preliminary analysis of the ‘two-mouthed’ trout revealed that the condition was caused by an injury to the fish earlier in its life, rather than a genetic repeat or other mutation,” wrote James Lee, a research fellow at Harvard’s Museum of Comparative Zoology.

Lee said it appeared that a muscle in the trout’s mouth was severed in the past, causing thin membranes between the lower jaw bone and the floor of the mouth to split. He said that caused the floor of the mouth to drop.

“This gives the appearance of two jaws. It also results in the fish having no practical floor to its mouth,” Lee wrote in an e-mail.

Despite the odd condition, Lee wrote, the trout appeared to be in good health and was able to live, feed and grow to adult size. The fish came from a Nebraska fish hatchery.

Olberding, 57, caught the unusual trout at Holmes Lake in December. The trout had a normal mouth and another one below it that led nowhere. He snapped photos of the fish and then cut off the head and put both pieces in the freezer.