Mystic — Herds of lions, swarms of bees and a handful of ninjas kept company with the fish at Mystic Aquarium Wednesday night for a free, last-minute trick-or-treating event.

Aquarium spokesman Erin Merz said more than 8,200 people — families from towns beleaguered by power outages, downed trees and power lines — made the trip for a safe Halloween haven among the aquarium's exhibits for the evening.

"We were talking amongst ourselves — our staff and our volunteers and their families were so impacted (by Sandy) — so we thought, what the heck, we'll open this up to everyone who wants to come," she said.

Officials in several local towns had canceled scheduled parties and parades, with some even asking parents to postpone trick-or-treating to a specified later date. But for purists intent on doing Halloween on Halloween, the aquarium opened up all indoor and outdoor exhibits, staffing a path of 10 trick-or-treating tables throughout the outdoor exhibit.

Less than 24 hours of planning went into the event, Merz said, with volunteers and staff raiding local stores for bags of candy and retrieving decorations that had been tucked safely away ahead of the storm. Merz said some good Samaritans, upon learning why those enlisted were ringing up armfuls of sweets, pitched in on what turned out to be 40,000 pieces of candy — an entire minivan full of sugar.

Social media and email blasts to aquarium members brought in the crowds, creating a traffic jam from the I-95 exit, past Olde Mistick Village, where an annual trick-or-treating event also was being held. Even Republican U.S. Senate candidate Linda McMahon made an appearance, handing out candy to the costumed masses.

The indoor exhibits were in full swing as well: Spiderman hung his elbows off the glass of the sting ray pool, petting swimming passersby; a princess pressed her face to the glass, admiring a school of fish.

Parent chaperones shared a prevailing sentiment of gratitude for the aquarium, which brought in 35 volunteers and staffers to lend a hand.

"It was very nice of them to do this," said David Flagge of Old Lyme, who lost power at home and came with his daughter, Isabella, 9, sporting a dark-braided wig as Wednesday Addams.

Isabella's best friend, Jack Beauprez, also 9, was in tow, in place among the aquarium's regular inhabitants in his shark costume. Two defeated legs protruded from his hood's sharp, toothy mouth — dinner.

"I've been getting lots of compliments," Beauprez said.

Tara and Jeff Autrey of East Lyme were busy trying to snap a photo of daughter Ashlyn, 2, next to one of the tanks; Ashlyn, cozy in a gray, striped onesie of a cat costume, was more interested in taking stock of her loot in a plastic jack-o'-lantern bucket. The family was just there Sunday.

"The fish are all old hat," Tara said.

After losing power in the storm, the couple said they were happy to have somewhere to bring their daughter.

"We think it's really great that they did this tonight," Jeff said. "I think the kids are having a lot of fun."

By 7:30 p.m., 2½ hours in and a half hour before close, the flow of candy was still going strong. By 8 p.m., with the last of it handed out to the exodus of trick-or-treaters, all 40,000 pieces of candy had found new homes.

Merz said the turnout was overwhelming — in a good way.

"When you plan an event of this magnitude in less than 24 hours' notice, you never really know what to expect," she said. "I think everyone was really happy to have a Halloween because they almost didn't this year."

a.isaacs@theday.com