Assertion: flounder's fin | /r/MadeOf | one spine
Facets:
Source sentences:
text: The pectoral fins contain 15–18 soft rays each; the pelvic fins are thoracic and contain one spine and six soft rays; the caudal fin is forked.
text: The single dorsal fin contains four to six spines and 15 to 19 soft rays; the anal fin contains three spines and 10 to 12 soft rays.