The first call to Miami-Dade's 911 operator was frantic. A python had wrapped itself around the neck of the family pet, a 60-pound Siberian husky named Duke. The snake was choking the life out of the dog.

The second call, five minutes later, said fire-rescue officials were too late. Duke was dead.

An off-duty fire captain and reality TV star, Charles "Big Country" Seifert of the Animal Planet show Swamp Wars, managed to capture the 10-foot-long, 38-pound snake. It wasn't one of the thousands of Burmese pythons that have plagued the Everglades for 20 years and become the poster child for Florida's invasive species problems.

What killed Duke was another, nastier species for Floridians to worry about: a North African python, also known as a rock python, breeding freely in the suburbs at the edge of the Everglades.

"This doesn't appear to be someone's pet python," Carli Segelson of the Florida Fish and Wildlife Conservation Commission said this week. Instead, she said, "it was probably from that wild population."

"Now we're afraid to go outside," said Michelle Rojas, 43, who along with her 22-year-old son tried to pull the snake off their dog, to no avail. In nine years of living in that neighborhood, "this is something I never would've expected to happen."

She said her two younger children, ages 15 and 12, were traumatized by watching their beloved pet strangled to death the night of Aug. 30. She's upset too, explaining, "This thing could've gotten one of my kids."

Her second husky, Casper, grew up with Duke. "Now he's really sad and missing him," she said.

State biologists first got a report in 2002 that someone had spotted a North African python east of Everglades National Park and south of the Tamiami Trail. Not until 2009 were they able to document that a colony of them was living there, Segelson said.

In the four years since, she said, state biologists have captured 27 North African pythons in that area, including two juveniles — another sign that they're breeding. Then came the Aug. 30 backyard attack that killed Duke.

Of the 26 species of pythons, rock pythons have an especially nasty reputation. They are so ill-tempered, "they come out of the egg striking," Kenneth Krysko, senior herpetologist at the Florida Museum of Natural History in Gainesville, told National Geographic in 2009. "This is just one vicious animal."

In its native range in sub-Saharan Africa, the rock python eats such animals as antelopes, warthogs and herons, but there are at least two verified reports of attacks on humans in the wild. A rock python that had escaped from a Canadian pet store was blamed last month for the asphyxiation of two sleeping boys, ages 4 and 6.

As a result of Duke's death, Segelson said, "we do have people out today canvassing in that area, letting people know that we would like to get reports about any sightings of these snakes and also giving out basic safety tips on what to do if you see one."

She added that "it's important to note that rock pythons don't generally attack humans unless they're provoked, but you should supervise children and keep an eye on small pets."

Rojas said she was inside the house about 10 p.m. and heard something that sounded like screaming, so she ran outside. "It was the dog," she said. "He was screaming. It sounded so weird. Because the snake was around his throat he couldn't sound like normal."

She and her son tried prying the python loose, she said, then tried using garden shears on it, but nothing would make the snake loosen its death grip. "It was just too strong," she said.

After Seifert captured the snake, firefighters discovered it had two bite wounds on its neck, suggesting there had been a battle — and raising questions about who struck first, according to Capt. Jeff Fobb of Miami-Dade Fire Rescue's Venom One unit, which responds to all snake-related emergencies. Fobb also stars on Swamp Wars.

"It's difficult to tell if the snake attacked the dog," Fobb said. "A snake would've had trouble eating a dog that size, so it might've been a defensive move" to attack the dog.

Either way, Fobb said, "it's a cause for concern."

Times researcher Caryn Baird contributed to this report. Craig Pittman can be reached at craig@tampabay.com.