The blurred lanternshark (Etmopterus bigelowi) is a little-known species of dogfish shark in the family Etmopteridae, found around the world in benthic and pelagic habitats from a depth of 110 m (360 ft) to over 1 km (0.62 mi) down.

It has been assessed as of Least Concern by the International Union for Conservation of Nature, because of its wide distribution and lack of threat from fishing pressure.

Japanese ichthyologists Shigeru Shirai and Hiroyuki Tachikawa described the blurred lanternshark in a 1993 article in the scientific journal Copeia, as part of a taxonomic revision of the Etmopterus pusillus species group.

[2] The E. pusillus species group is distinguished from other lanternsharks in having truncate (ending in a flat crown as though the tip were cut off), irregularly arranged dermal denticles.

In the Indo-Pacific, it has been reported from off Okinawa and Australia, as well as on the Emperor and Hancock Seamounts in the central North Pacific and over the Nazca Plate off Peru.

[2] Growing to a length of at least 67 cm (26 in), the blurred lanternshark has a slender body, large head, and short tail.

There are 19–24 tooth rows in the upper jaw, each with a narrow central cusp flanked by 2–4 pairs of smaller cusplets, increasing in number with age in males over 45 cm (18 in) long.