Jan 08, 2025

Heartless creatures: How some animals survive without a heart

Siddhartha Jana

The heart is a vital organ for humans, pumping blood and keeping the body's tissues and organs circulating.

Source: Canva

However, some animals rely on alternative means to distribute oxygen and nutrients because they lack a heart.

Source: Canva

One example is flatworms, which carry nutrients and oxygen throughout their bodies by diffusion rather than a complicated internal structure.

Source: Canva

Because of their simple body shape, jellyfish do not require a heart because they pump nutrients and oxygen through a hollow chamber.

Source: Canva

Sea sponges, which are normally found on the ocean floor, lack a heart but employ a simple system to transport water through their bodies to distribute nutrients and oxygen.

Source: Canva

Starfish, due to their particular physiology, absorb nutrients through microscopic pores on their surface and circulate them throughout their bodies to fulfil critical activities.

Source: Canva

Tapeworms, which inhabit other animals' intestines, use bodily holes to absorb and transfer nutrients because they don't have hearts.

Source: Canva

Without a heart, sea cucumbers use water flow to deliver nutrients and carry out other essential tasks, much like starfish and sea urchins.

Source: Canva

Hydra are simple aquatic animals that rely on their structure to directly absorb nutrients from the surrounding water. They lack a heart and a brain.

Source: Canva

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