chub mackerel vs Scomber japonicus

chub mackerel and Scomber japonicus both are nouns.

Word	Noun	Adjective	Verb	Adverb
chub mackerel	Yes	No	No	No
Scomber japonicus	Yes	No	No	No

As nouns, chub mackerel and Scomber japonicus are synonyms defined as:

chub mackerel and Scomber japonicus: small mackerel found nearly worldwide

Other synonyms of chub mackerel include tinker.

chub mackerel (noun)	Scomber japonicus (noun)
small mackerel found nearly worldwide	small mackerel found nearly worldwide