Assertion: goldfish's fin | /r/CapableOf | rock up in the water
Facets:
value: lengthwise
type: MANNER
Source sentences:
text: The paired (pectoral and pelvic) fins prevent the fish from pitching (rocking up and down lengthwise) in the water; the median (caudal, dorsal and anal) fins prevent it from yawing (wandering) and rolling (rocking from side to side); forward movement is achieved by S-shaped undulations of the body and caudal fin; steering and precise control of movement are achieved by varying the angle of the pectoral fins.