Hippos: Semi-Aquatic Environment

Hippos are also very well evolved for a semi-aquatic environment. The hippo has large, razor sharp canine teeth perfect for fighting. The canines of the upper and lower jaw grind together sharpening each other. When hippos fight using such sharp teeth, having thick, protective skin is very important. The skin of the hippo can be up to two inches thick. However, even with thick skin, hippos still get torn up in a fight. Normally having an open wound in an aquatic environment would lead to infection, but hippos have a way to protect their skin. Hippos have a gland that secretes a red fluid called blood sweat. Blood sweat acts as an antiseptic and a sunblock. It is believed that hippos get this medicinal benefit by eating sausage fruit. Blood
Hippo’s have a large, multi-chambered stomach that takes up about two thirds of their abdominal cavity. The food a hippo ingests is then digested by bacteria in the stomach. The hippo is then able to digest the bacteria. Unlike the hippos’ terrestrial ancestors that need to graze on land all day to get enough nutrients, the hippo cannot stay out of the water very long during the day. Therefore, the hippos go on land at night to graze. The first chamber of the stomach has a thick lining that works to mechanically breakdown food. The second chamber hold more digestive juices and uses chemical and mechanical breakdown. Herbivores tend to have multiple chamber stomachs to increase the time the food spends in the stomach for fermentation and breakdown. The majority of the nutrients absorption takes place in the small intestine. Since the hippo has a very large stomach relative to the size of their large intestine, the large intestine doesn’t have very long to reabsorb water, making the fecal material very
A hippo’s lungs are not divided into lobes. This allows them to inhale large amounts of air quickly, allowing them to hold their breath underwater for up to five minutes. With large lungs filled with air a hippo would float, however hippos have solid leg bones that act as anchor to keep the hippo from floating. Unlike the hippos ancestor the hippo’s leg bones are made of solid bone, meaning they have no marrow cavity. Since the hippo can’t swim, it is important that it sinks so it can tip-toe along the bed of the water