METHUEN — Deborah Salerno and her husband were enjoying Saturday evening's warm weather with some iced coffee when they decided to take a stroll around the city's newly opened boat ramp.
The couple was admiring a small monument on the site when Deborah saw, about five feet below the grassy edge of the bank, a scaly creature floating belly-up in the water, with four short legs and a tail nearly the length of its body.
"Then I noticed in the water, a floating dead alligator," she said. "I called the police. I didn't know who to contact because I never heard of an alligator in the Merrimack."
Salerno said she became convinced the two-foot-long specimen was an alligator when her husband brought up the gator-like creature called a caiman that was found roaming the streets of Lowell earlier this month.
Further investigation, however, revealed the critter was no gator.
Though its belly looked like it could belong to an alligator, the reptile's back was covered in characteristic black and white markings, and it had smoother skin than an alligator.
Dan Bilodeau, a manager at Plaistow's Zoo Creatures pet store, identified the deceased reptile as an Argentine black and white tegu, a large lizard that is legal to own as a house pet in Massachusetts.
The tegu is native to South America and is omnivorous, meaning it eats both meat and fruits, according to the International Union for Conservation of Nature Red List. The creatures are commonly kept as pets and live on land, not in water.
Salerno said when the police arrived, they decided not to remove the tegu from the water. She expressed concern about the body before realizing it wasn't an alligator.
"I said, do you think there's more?" she asked, noting that "two alligators in New England" would have been "too much of a coincidence."
Lt. Stephen Smith of the Methuen Police Department said officers did respond to Salerno's call, but deemed no further action was needed.
"For the most part, if it's just in an area that's pretty much not a public area, we just let nature take its course," he said.
After learning the creature was a tegu, she said she was less worried.
"I had thought it was an alligator and I felt lost because no one was trying to help me, no one was taking it seriously," Salerno said.