branchiopod vs daphnia

branchiopod and daphnia both are nouns.

Word	Noun	Adjective	Verb	Adverb
branchiopod	Yes	Yes	No	No
daphnia	Yes	No	No	No

As nouns, daphnia is a hyponym of branchiopod; that is, daphnia is a word with a more specific, narrower meaning than branchiopod:

branchiopod: aquatic crustaceans typically having a carapace and many pairs of leaflike appendages used for swimming as well as respiration and feeding
daphnia: minute freshwater crustacean having a round body enclosed in a transparent shell; moves about like a flea by means of hairy branched antennae

Other hyponyms of branchiopod include water flea, fairy shrimp, Artemia salina, brine shrimp, tadpole shrimp.

branchiopod (noun)	daphnia (noun)
aquatic crustaceans typically having a carapace and many pairs of leaflike appendages used for swimming as well as respiration and feeding	minute freshwater crustacean having a round body enclosed in a transparent shell; moves about like a flea by means of hairy branched antennae

branchiopod (adjective)	daphnia (adjective)
of or relating to or characteristic of the subclass Branchiopoda