Sminthurides malmgreni is a common and widespread species (more common than
Sminthurides aquaticus). The body is yellow in colour with longitudinal bands of dark pigment. There is also a black form,
Sminthurides malmgreni ssp
nigrescens. Males reach 0.3 mm in length whereas females grow to 0.6 mm.
In
Sminthurides species, the male antennae are modified to grasp the female during mating and the long spine on the second antennal segment (ant2) is curved. In this species the fourth antennal segment in the female is not divided into clear subsegments.
