These water fleas are very small, usually 2-5 mm long, with an overall shape similar to a kidney bean. The body is enclosed by a transparent shell-like structure, called a carapace, that is mostly made of chitin. Due to its transparent carapace, this species tends to be the color of what it is currently eating. The carapace extends into the head shields, an important diagnostic characteristic for this species. They have two sets of long, doubly branched antennae and six thoracic appendages that are held inside of the carapace and help to produce a current of water, carrying food and oxygen to their mouths and gills. They also have two large claws, used mainly for cleaning the carapace. They have one compound eye, which appears as an anterior dark spot, and one simple eye (ocellus). Males are smaller than females (typically only 2 mm long while females are 3-5 mm long) but have longer antennules and modified, hook-like first appendages used for clasping females during mating