Assertion: crab's pair | /r/CapableOf | serve as propulsion
Facets:
value: in aquatic species
type: OTHER
Source sentences:
text: The first five abdominal segments each bear a pair of biramous (branching in two) pleopods (lamellar structures which serve the function of gas exchange, and in aquatic species serve as gills and propulsion), and the last segment bears a pair of biramous uropods (posterior limbs).