Question

What animal has no hearts?

Answer 1

Hint: The heart is a muscular organ that pumps blood via the blood vessels of the circulatory system. It is present in the majority of the animals. The blood transports oxygen and nutrients to the body cells. Some animals do not possess a heart. These animals are so small and so they are not dependent on blood and nutrients being pumped around to the internal organs. Some animals do not possess any internal organs, in such cases also the heart is absent.

Complete answer:
The animals that do not have a heart include jellyfish, flatworms, corals & polyps, starfish, sea anemone, sponges, sea cucumbers and sea lilies.
The Jellyfish is the biggest animal without a heart. It is a simple and primitive creature. It has no heart because it has no blood flowing around inside its body. The jellyfish can grow up to eight feet. It has the special ability to regenerate its lost body parts. Due to this, the scientists suspect that the jellyfish can even live eternally. Jellyfish feed on tiny fishes and zooplankton. It catches the food with the help of its tentacles and directs the food into its mouth. Once the food is digested, waste will leave the body through that same opening.

Note:
The Flatworms are flat in shape and so they do not have a heart. They rely on a process called diffusion to circulate oxygen and nutrients throughout the body. Corals & polyps have no blood or vessels so there’s no need for a heart. Animals like starfish, sea anemone, sponges, sea cucumbers and sea lilies are super simple creatures and they don’t have internal organs and hence no heart.