[1][2] It occurs in waters around Svalbard at depths of 37–95 metres (121–312 ft).

[1] M. martensi is only known from four specimens collected in 1861 in two fjords on the island of Spitsbergen – Kongsfjorden and Isfjorden.

[3] They are all immature, and measure 6–8 millimetres (0.24–0.31 in) long.

[4] It was redescribed in 1968, and tentatively assigned to the genus Uristes.

[3] In 1991, J. Laurens Barnard and G. S. Karaman erected a new genus, Martensia, for this species alone,[1] and the genus remains monotypic.