Which is the longest-living animal?

Sponges make up one of the oldest, most primitive groups of animals on Earth. Sponges have existed for at least 500 million years. Sponge cells do not have specialized purposes. Each of a sponge’s individual cells can transform to complete the job of any other cell in the body. This lack of specialization means that sponges do not have tissues, like every other type of animal. In fact, in laboratory settings, a sponge that is destroyed in a blender can reform itself as the cells swim back together and take on the form and job needed for recovery. Giant barrel sponges feed by filtering water through the body wall, trapping food particles and excreting waste materials into the inner bowl. The, now filtered, wastewater exits the sponge through the large opening at the top (called an osculum). They also obtain oxygen from the water during this process. The giant barrel sponge can live for up to 2,300 years. That is more than 10 times as long as the bowhead whale, which is the longest-lived mammal.

 

Picture Credit : Google