The duckbill pugolovka (''Anatirostrum profundorum'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of gobiid fish

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the southern part of the

Caspian Sea The Caspian Sea is the world's largest inland body of water, often described as the world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia; east of the Caucasus, west of the broad steppe of Central Asia ...

. It is characterized by its special flattened and elongated head that resembles a duck's bill.Brian W. Coad
Freshwater Fishes of Iran
(accessed 18 Feb 2015) It is the only known species in its

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

. It was initially found in 1904 at a depth of (arguably 447 m). Only recently more samples of this species have been collected from

Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...

ian waters, where it mainly lives at 50–100 m depth. The fish are on average long and at maximum 13 cm.

References

Benthophilinae Monotypic fish genera Fish described in 1927 Fish of Western Asia Fish of the Caspian Sea {{Gobiidae-stub