costia vs mastigophoran

costia and mastigophoran both are nouns.

Word	Noun	Adjective	Verb	Adverb
costia	Yes	No	No	No
mastigophoran	Yes	No	No	No

As nouns, mastigophoran is a hypernym of costia; that is, mastigophoran is a word with a broader meaning than costia:

costia: a flagellate that is the cause of the frequently fatal fish disease costiasis
mastigophoran: a usually nonphotosynthetic free-living protozoan with whiplike appendages; some are pathogens of humans and other animals

Other hypernyms of costia include flagellate, flagellate protozoan, flagellated protozoan, mastigophore.

costia (noun)	mastigophoran (noun)
a flagellate that is the cause of the frequently fatal fish disease costiasis	a usually nonphotosynthetic free-living protozoan with whiplike appendages; some are pathogens of humans and other animals