salp vs salpa

salp and salpa both are nouns.

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

As nouns, salp and salpa are synonyms defined as:

salp and salpa: minute floating marine tunicate having a transparent body with an opening at each end

salp (noun)	salpa (noun)
minute floating marine tunicate having a transparent body with an opening at each end	minute floating marine tunicate having a transparent body with an opening at each end