The Beijing Aquarium page should not be overfilled.
The official site currently provides opening hours, show information, and venue descriptions, but not a complete penguin species page like many Japanese or U.S. facilities have. The penguin lead that can be checked is a 2019 Beijing media report: Beijing Aquarium introduced penguins from the southwest coast of Africa, the African penguin, Spheniscus demersus.
So this page does not force in Magellanic penguins, and it does not present Penguin Island as a specialist exhibit with complete data.

What to see
Beijing Aquarium sits inside Beijing Zoo, and overall it is a large inland aquarium. Its main route includes rainforest, touch pool, Undersea Ring, sharks, whale-and-dolphin bay, and ocean theatre.
Penguin Island’s value is that it lets city travelers in Beijing reliably see a temperate penguin. African penguins do not come from ice and snow; they come from the southern African coast, and the bare skin around the eyes helps with heat release. That connects it to the same species line as the sky penguins at Sunshine Aquarium.
To understand another temperate coastal Spheniscus penguin, continue to the Humboldt penguin. If you want more species, East Asian facilities can point you toward Nagasaki Penguin Aquarium or Yokohama Hakkeijima Sea Paradise.
For a large China facility comparison, separate Beijing from Chimelong Ocean Kingdom Zhuhai and Ocean Park Hong Kong South Pole Spectacular: Beijing is the zoo-plus-aquarium city day; Zhuhai and Hong Kong are larger chilled-exhibit routes.

How to plan it
For tickets, Beijing’s official English tourism page lists peak-season adults at CNY 175 and off-season adults at CNY 170, with each ticket allowing one entry to Beijing Zoo and Beijing Aquarium. That means it is often treated as a zoo-plus-aquarium day trip.
In peak season, April to October, the aquarium opens at 09:00 and closes at 17:30; off-season hours are 10:00 to 17:00. Final ticket sales and entry are earlier.
Before leaving, the official site or official WeChat is the safest check, especially for show times and temporary closures.

Penchan Says
The key here is restraint.
When the data is incomplete, do not fill species gaps with secondhand claims. Write what can be confirmed, and leave the rest for the next official update.
References
FAQ
Which penguin species can be confirmed at Beijing Aquarium?
The guide follows a 2019 Beijing media report that points to penguins from the southwest African coast, meaning African penguins.
Does Beijing Aquarium have Magellanic penguins?
This page does not force in Magellanic penguins. It only writes the African penguin lead that can be checked and avoids filling species gaps with secondhand claims.
How do Beijing Aquarium tickets and hours work?
Beijing's official English tourism page treats it as a Beijing Zoo plus Aquarium ticket with one entry, and the article notes different peak and off-season hours.