Scientists discover first known animal that doesn't breathe

Henneguya salminicola, a parasitic blob that infects fish and underwater worms, is the only known animal on Earth that does not breathe. Unlike all other multicellular animals, it lacks a mitochondrial genome and respiratory genes. This unique parasite has evolved to be almost unicellular, losing tissues, nerve cells, and muscles. Scientists are uncertain how H. salminicola acquires energy without breathing, but speculate it may import ATP directly from its host. This discovery challenges traditional views of animal evolution towards complexity.