Haplophthalmus danicus Budde-Lund, 1877
This species is introduced from Europe. It has been recorded from the Auckland region and Raoul Island, but is probably under-reported due to its small size.
A very small slater (under 4 mm), the body is white to cream in colour. The dorsal surface is covered with small tubercles, these are arranged in longitudinal ridges on pereon. Each eye is composed of a single black ocellus. Pleopodal lungs absent. Does not roll into a ball.
This species can be confused with small native Styloniscidae, which can be similar in colour and size. Can be distinguished by examining the eyes - in Styloniscidae each eye is composed of three ocelli set in a triangle, while the eye of H. danicus is made of a single ocellus.