Carassius carassius vs crucian carp

Carassius carassius and crucian carp both are nouns.

Word	Noun	Adjective	Verb	Adverb
Carassius carassius	Yes	No	No	No
crucian carp	Yes	No	No	No

As nouns, Carassius carassius and crucian carp are synonyms defined as:

Carassius carassius and crucian carp: European carp closely resembling wild goldfish

Other synonyms of Carassius carassius include Carassius vulgaris.

Carassius carassius (noun)	crucian carp (noun)
European carp closely resembling wild goldfish	European carp closely resembling wild goldfish