Assertion: fish's type | /r/DefinedAs | placoid
Facets:
value: usually
type: TEMPORAL
Source sentences:
text: Similarly, the surface of the skin may be naked (as in moray eels), or covered with scales of a variety of different types usually defined as placoid (typical of sharks and rays), cosmoid (fossil lungfish and coelacanths), ganoid (various fossil fish but also living gars and bichirs), cycloid, and ctenoid (these last two are found on most bony fish).