Discover surprising facts about fish, tanks, water, and life behind the glass.
Aquariums are full of science. Fish use senses that work underwater, tiny bacteria help process waste, plants respond to light, and huge public exhibits rely on engineering as well as biology.
Gills remove dissolved oxygen from water as it passes over thin tissues.
Learn MoreMoving in a coordinated group can help fish find food and avoid danger.
Learn MoreFish do not sleep exactly like people, but many have regular periods of reduced activity.
Learn MoreWater, glass, and air can bend light and make objects look shifted or magnified.
Learn MoreA healthy tank contains microorganisms that are too small to see easily.
Learn MoreHuge exhibits rely on pumps, filters, sensors, strong viewing panels, and life-support systems.
Learn MoreMost fish move water across their gills, where oxygen can pass from the water into the blood. Carbon dioxide moves in the opposite direction. Because the amount of dissolved oxygen in water can change, temperature, water movement, plant life, and the number of animals in a tank can all affect the oxygen available.
Many small fish naturally live in groups. Schooling can make it harder for a predator to focus on one individual, and group members can respond quickly when another fish changes direction. In an aquarium, species that are naturally social may behave more normally when kept in an appropriate group.
Many fish become less active at certain times of day or night. They may hover in one place, hide in a cave, rest near the bottom, or change color slightly. Most fish do not have eyelids, so their eyes may remain open even while they are resting.
Light changes direction when it moves between materials such as air, glass, and water. This is called refraction. It can make a fish look closer, larger, or slightly displaced depending on the viewing angle. Curved aquarium windows can create even stronger visual effects.
Bacteria and other microscopic organisms live on filter material, rocks, plants, gravel, and many other wet surfaces. Some help break down waste, while others are part of tiny food webs. An aquarium is not just a home for the animals we can easily see.
A public aquarium holding very large animals or thousands of fish is also an engineering project. Water must circulate through filtration systems, temperature and chemistry must be monitored, and large viewing panels must safely hold back enormous water pressure. Biologists, aquarists, veterinarians, engineers, and technicians all help keep these systems working.