salp vs urochordate

salp and urochordate both are nouns.

Word	Noun	Adjective	Verb	Adverb
salp	Yes	No	No	No
urochordate	Yes	No	No	No

As nouns, urochordate is a hypernym of salp; that is, urochordate is a word with a broader meaning than salp:

salp: minute floating marine tunicate having a transparent body with an opening at each end
urochordate: primitive marine animal having a saclike unsegmented body and a urochord that is conspicuous in the larva

Other hypernyms of salp include tunicate, urochord.

salp (noun)	urochordate (noun)
minute floating marine tunicate having a transparent body with an opening at each end	primitive marine animal having a saclike unsegmented body and a urochord that is conspicuous in the larva