Cottonmouth gives 'virgin' birth at Snake World

Friday, September 7, 2012

BERRYVILLE -- "I've had snakes all my life, and I never knew this could happen!" said Dale Ertel, owner of Snake World in Berryville.

A captive female Florida Water Moccasin (cottonmouth) he obtained half-grown two years ago gave live birth to one baby. The viper had never been kept with another snake.

He said a customer noticed there was a baby in the tank with the 4-foot mother cottonmouth on Saturday.

"It had already shed, and it usually takes three or four days before the first shed, so it might have already been a few days old," he said.

Ertel called a fellow collector with connections to a biologist at Jonesboro University, and found out some snakes can reproduce by "parthenogenesis," or asexual reproduction.

"It's rare in captive populations," Ertel said, "but it can happen."

His friend told Ertel he had had a Fer-de-Lance viper for three years, then sold it to a Springfield museum, who had it for five years when it gave live birth to 11 offspring.

"It had never been introduced to a mate," Ertel said.

Some snakes that may appear to produce virgin birth offspring instead actually delay gestation by what is known as "sperm retention," according to author Chad Minter in "Venomous Snakes of the Southeast."

Ertel knew about this.

"A snake can be fertilized and twist its uterus so it won't give birth until conditions are favorable," he said.

But that's not the case with his cottonmouth.

"This snake has never been near any other snakes," he said. "I got it when it was immature, not old enough to be mating."

Ertel said the cottonmouths around here are Western Water Moccasins, a different sub-species from his snake. In captivity, cottonmouths can live up to 20 years, he said.

Minter records another occasion of parthenogenetic birth. In the wild, cottonmouths give birth to eight to 12 live young, usually in the fall. He reported a case of two virgin births from a cottonmouth in Georgia that had been in captivity for more than five years.

"Parthenogenesis has been confirmed in at least one other species of pit viper, and many species of lizards," Minter wrote. "The babies remained unusually small, though they ate well. Their skulls also seemed to be slightly deformed."

Ertel said the new baby, about 7 inches long, has already eaten its first meal, a newborn rat.

"I just wonder if there were more than one baby," he said. "It's possible if there were more, the mother ate them. They are cannibalistic, confined in a small space like that. That baby might have been the last one left."

He plans to keep the new cottonmouth at Snake World.

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