Assertion: sponge | /r/HasAspect | skeletons of glass or protein
Facets:
value: unlike some seaweeds
type: OTHER
value: unlike corals
type: OTHER
Source sentences:
text: Unlike corals and some seaweeds that secrete calcium carbonate skeletons, sponges have skeletons of glass or protein (if they have them at all), and they are less likely to be affected by ocean acidification, which may tip the competitive balance in their favor.