Is the "Altie" a monster or fish?

Professor Hank Bart refutes claims of a legendary water monster on the Discovery Channel"s series, “Beasts of the Bayou.” (Photo from the Discovery Channel)

“Beasts of the Bayou,” the Discovery Channel"s new series, focuses in its second episode on dueling theories about a legendary water monster, the Altamaha-ha, or “Altie.”

In the show, two teams seek to explain recent sightings. One team includes Louisiana shrimp boat captain Blimp Cheramie and his crew, who are determined to prove the existence of the Altie. The other team, headed by Tulane biologist and fish scientist Hank Bart, has a different explanation.

According to the show"s narrator: “Witnesses describe an enormous creature, at least 20 feet in length, with an elongated neck, a mouth filled with razor sharp teeth and a snakelike, spiny tail.”

Altie sightings have occurred in Georgia and Florida rivers as far back as colonial times, but since then the beast has supposedly migrated to Louisiana rivers, lakes and bayous.

Followed by the documentary filmmaker"s camera, Bart enters the Royal D. Suttkus Fish Collection of the Tulane University Biodiversity Institute.

“This collection is the largest fish collection in the world,” says Bart, a professor in the Department of Ecology and Evolutionary Biology. Opening a large stainless steel bin, Bart and an assistant lift out an enormous fish with needle-like teeth and scales like armor.

“This is an alligator gar,” says Bart. “The largest gar on record, I believe, was 20 feet in length.”

Blimp and his crew try to lure an Altie with noise, lights and finally with themselves as bait.

But Bart suggests an alternate hypothesis: so-called Altie sightings have actually been sightings of large alligator gars. Gars have the capability of breathing air, according to Bart.

Blimp"s final attempt to lure an Altie turns up a large but gentle manatee. His conclusion? “Well, at least we didn"t prove that it doesn"t exist!”

The episode, “Loch Ness Swamp,” which premiered on July 10, will re-air on Thursday (July 17) at 2 p.m. Central time. Check your local listings.