trepang vs holothurian

trepang and holothurian both are nouns.

Word	Noun	Adjective	Verb	Adverb
trepang	Yes	No	No	No
holothurian	Yes	No	No	No

As nouns, holothurian is a hypernym of trepang; that is, holothurian is a word with a broader meaning than trepang:

trepang: of warm coasts from Australia to Asia; used as food especially by Chinese
holothurian: echinoderm having a flexible sausage-shaped body, tentacles surrounding the mouth and tube feet; free-living mud feeders

Other hypernyms of trepang include sea cucumber.

trepang (noun)	holothurian (noun)
of warm coasts from Australia to Asia; used as food especially by Chinese	echinoderm having a flexible sausage-shaped body, tentacles surrounding the mouth and tube feet; free-living mud feeders