Can any animal live for years without food?

Food is our primary source of nutrients, and it is not only for us humans but also to the animals living around us. When we eat, our body absorbs the nutrients from our food to keep our body healthy and functioning correctly. With this said, we can say that food is essential to our body; that is why experts recommend various foods for us to maintain a healthy diet.

Furthermore, an average adult can only last for roughly three weeks without food, provided that they are still drinking water. But without water, the average adult can only last for three to four days, which is an entirely different thing. Meaning to say, a person needs both food and water to survive since water makes sixty percent of our body.

The same thing goes for animals. They also need food and water to survive, creating a food chain in the process. For example, a cat may only last for up to three days without water but could last more than three days without food. Although regardless of the situation, food is still vital for both animals and humans for us to have a healthy body.

Interestingly, not all animals have the same capacity in survival. Some animals can only last for a few days without water, while some could last longer than a week or two. Surprisingly, there is one group of micro-animals called the tardigrade, also known as water bears, which could last for thirty years without eating food. 

With this said, several questions might come up in our minds since we already established earlier that humans and animals need food and water to survive. However, the water bears appear to be a contrast to the typical way of living for other animals. What is the scientific explanation behind this incredibly unique characteristic of tardigrades? How are they able to survive for years without consuming anything?

What is Tardigrade?

A tardigrade is a group or a phylum of eight-legged micro-animals. It is pretty small and only spans for 0.002 inches to 0.05 inches long. It has quite an adorable appearance for a microscopic animal, which is why it is also known as the water bear or the moss piglets. 

One interesting fact about the tardigrade is its almost indestructible bodies, which can survive in outer space, as well as withstand intense pressure at the bottom of the ocean. This adamant body allows the tardigrade to survive in extreme temperatures that are inhabitable by other organisms.

Because of its tough nature, they are capable of living in various environments, but they prefer to live in semi-aquatic or moist places. We can say that they can live anywhere since they can survive a minus 328 degrees Fahrenheit, as well as radiation. B7ecause of its durability, researchers from Oxford and Harvard universities, speculated that water bears could still survive even after humans are long gone, and while various catastrophic events occur on our planet. In fact, water bears lived through the planet’s five significant extinction events. 

One more incredible feature of the water bear is its ability to suspend its metabolism, also known as cryptobiosis. Cryptobiosis is a state of some organisms wherein they don’t entirely stop their metabolism, but significantly lowers them to the degree that they won’t need food to survive. Once the tardigrade undergoes this state, its metabolism drops to less than 0.01% of normal and 1% for water content. While under this state, their bodies can survive for roughly thirty years or longer without eating. After the prolonged fasting, a water bear can simply go back to its original metabolic state and live its everyday life, foraging, reproducing, and rehydrating.

With all of these features, we can say that tardigrade is a pretty exciting animal. They have features that far outweigh other creatures, mainly when it comes to durability. Not all organisms are capable of surviving under extreme conditions. Furthermore, not all organisms can last for years without eating, which makes the water bear a unique animal. We might even come to think that tardigrades are indestructible or invincible, but this is not true. Usually, tardigrades only live for three to four months, as well as up to two years for other species, although these numbers don’t include their non-metabolic state.