This Animal Has No Heart
The impossible claim This animal has no heart, no blood, and no brain — and it can regrow its whole body from a single arm. The verified facts Sea stars (“starfish” — though they’re not fish) are echinoderms, cousins of sea urchins, and they break almost every rule we associate with animals: No heart, no blood — seawater is pumped through their water vascular system instead, and that hydraulic pressure is what powers the hundreds of tiny tube feet they walk with No brain — just a nerve ring around the mouth and radial nerves running down each arm They eat with their stomach outside their body — a sea star pulls a mussel’s shells slightly apart, everts its cardiac stomach through the tiny gap, and digests the prey externally before sucking the soup back in Regeneration: lose an arm, it regrows — weeks to months. Some species (Linckia) can rebuild an entire body from a single detached arm plus part of the central disc; full regrowth can take up to a year Most have five arms, but the sunflower sea star can carry up to 24 Watch 🎬 See the Short on YouTube — This Animal Has No Heart ...