Traditional Culture Encyclopedia - Photography and portraiture - What are the animals without hearts? (Please give specific examples, thank you.)

What are the animals without hearts? (Please give specific examples, thank you.)

Protozoa, the lowest level of eukaryotic unicellular animals. Of course not. Amoeba, radiolarian, flagellate, theropod, trumpet worm

Nematodes consist of about 20-30 cells and have no heart. trichomonad

Porphyra is a primitive multicellular organism. Although its cells have begun to differentiate, they have not yet formed tissues and organs. sponge

Coelenterates, although cells have begun to differentiate, have not yet formed tissues and organs, and have a primitive nervous system. Hydra, jellyfish

Platycladus orientalis is the most primitive coelom triplet, with primitive excretory system and stepped nervous system. Mushrooms, trematodes, tapeworms

anguina tritici

Rotifer wheel microorganism

Echinocephala, prosthetic cavity animals. Spinhead worm