Assertion: sea urchin | /r/Desires | their water-vascular system
Facets:
Source sentences:
text: As with other echinoderms, sea urchins do not have a brain and instead rely on their water-vascular system which is like a circulatory system and comprises of water-filled channels that run through the body of the sea urchin.
text: Like other echinoderms the Sea Urchin doesn’t actually have a brain and just relies on their water vascular systems, which basically works like are circulatory system.