Sharks, lions, snakes, and the evolving expressions of beauty in the human form have something in common: Boston Public Schools families redeemed tickets to see their exhibitions for free this year.

According to the mayor’s office, 30,670 tickets were redeemed across all the participating institutions, a tally that’s coming to a close as the pilot season ends this Sunday, with no firm plans to re-up or expand it.

For the Institute of Contemporary Art, museum staff say the exposure let families and students discover new worlds. Gail Leavitt, director of visitor operations, said the vast majority who visited the museum through the BPS program were going for the first time.

But she said as the summer went on, more and more repeat visitors were making a visit.

“The program allows us to reach people that haven’t been exposed to the contemporary art before,” Leavitt said. “One of the most popular is the beautiful exhibition of Firelei Báez, currently on view this summer.”

Boston Mayor Michelle Wu told GBH’s Boston Public Radio this week that City Hall is working to extend the program.

“We are still in negotiations” with the museums, she said.

Cynthia Mead at the Franklin Park Zoo thinks that accessibility to the nearly 8,000 visitors from 90 schools is making a difference.

“The most popular is elementary age, that’s that outstanding group of students who are coming,” she said. “They are coming with their families and they’re enjoying a beautiful day out.

“Looking at the animals can tell you a lot of their habitat,” Mead added. “It is a gateway into opening the horizon in someone’s world.”

The New England Aquarium proved most popular among students and their families, with more than 10,000 tickets redeemed there since the program’s launch in February.

Students and their families can still enter for free on Sunday, August 11, by visiting the websites of the participating institutions: The New England Aquarium, The Franklin Park Zoo, The Institute of Contemporary Art, The Museum of Fine Arts, The Boston Children’s Museum and the Museum of Science.