daphnia: minute freshwater crustacean having a round body enclosed in a transparent shell; moves about like a flea by means of hairy branched antennae
branchiopod crustacean: aquatic crustaceans typically having a carapace and many pairs of leaflike appendages used for swimming as well as respiration and feeding
cirrus: a wispy white cloud (usually of fine ice crystals) at a high altitude (4 to 8 miles)