Hippos hang out in herds of 10 to 30 members, though some herds can be bigger. A herd is made up of mostly adult females and their calves, but also some adult males. One of those males is the boss of the whole group. He protects the herd by attacking any intruders that trespass in his territory.
http://www.nwf.org/Kids/Ranger-Rick/Animals/Mammals/Hippos.aspx
Quick Answer. When submerged underwater, hippos can hold their breath for 5 minutes or even longer if needed. Hippos have nostrils located on the top of their heads, which allows them to breathe even if the rest of their body is under water. Continue Reading.
https://www.reference.com/pets-animals/long-hippo-able-hold-its-breath-c0d7d68501af62dd
The river hippo can grow up to 13 feet in length, and weigh as much as a small truck - around 5000 pounds. The pygmy hippo is much smaller. River hippos spend the majority of their daylight hours in the water to keep cool.
https://www.wildrepublic.com/en/hippopotamus
The Scoop. The hippopotamus or hippo is well adapted for life in the water. These huge animals are found living in slow-moving rivers and lakes in Africa. With their eyes, ears, and nostrils on the top of the head, hippos can hear, see, and breathe while most of their body is underwater.
https://www.wildrepublic.com/en/hippopotamus
Hippos on Land. At sunset, hippopotamuses leave the water and travel overland to graze. They may travel 6 miles in a night, along single-file pathways, to consume some 80 pounds of grass. Considering their enormous size, a hippo's food intake is relatively low.
http://www.nationalgeographic.com/animals/mammals/h/hippopotamus/
About the Hippopotamus. Hippopotamuses love water, which is why the Greeks named them the “river horse.” Hippos spend up to 16 hours a day submerged in rivers and lakes to keep their massive bodies cool under the hot African sun. Hippos are graceful in water, good swimmers, and can hold their breath underwater for up to five minutes.
http://www.nationalgeographic.com/animals/mammals/h/hippopotamus/
Hippos are specially built for life in the water. Their eyes, ears, and nostrils are on the tops of their heads. That lets them get almost all the way under the water for maximum cooling, while still being able to see, hear, and breathe. When they want to, though, hippos can go completely underwater.
http://www.nwf.org/Kids/Ranger-Rick/Animals/Mammals/Hippos.aspx
Fortunately, hippos can nurse from their mothers either on land or underwater. They do this underwater by closing their valve-like ears and nostrils. Despite their size, hippos are actually quite efficient underwater. They can hold their breath below the surface for up to five minutes. When hippos are exposed to the sun, their skin actually produces an oily red substance, serving as moisturizer and sun repellant for their skin.
http://channel.nationalgeographic.com/wild/dangerous-encounters/articles/facts-to-catch-a-hippo/
Confidence votes 76.5K. Hippos can't breath underwater but they can hold their breath for long periods of time. They need to take a breath once every 4-6 minutes. + 19 others found this useful.
http://www.answers.com/Q/How_long_can_a_hippo_breathe_underwater
If necessary, hippos can store up to two days worth of grass in their bellies and then go for as long as three weeks without eating. Despite their overwhelming size and seemingly sluggish behavior, on land, hippos can reach impressive speeds of up to fourteen miles per hour (30 kilometers per hour).
http://channel.nationalgeographic.com/wild/dangerous-encounters/articles/facts-to-catch-a-hippo/
how long can a hippo hold its breath underwater
A hippo can hold its breath underwater for 5 minutes or even longer if needed. In underwater, hippos can hold their breath for 5 minutes or even longer if needed.