Animals feed
Polyps
Reef-building corals are colonies of animals called polyps, not underwater plants. Their plantlike appearance partly reflects a partnership with microscopic algae living inside their tissues.
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Octopuses have three hearts: two supply the gills and one supplies the rest of the body. Their oxygen-carrying protein contains copper and turns blue when oxygenated.
Cubes
Wombats produce distinctly cube-like droppings, shaped inside the intestine rather than by a square opening. Research links the shape to differences in the mechanical properties of the intestinal wall.