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

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of gobiid fish

endemic Endemism is the state of a species being found only 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 foun ...

to the southern part of the

Caspian Sea The Caspian Sea is the world's largest inland body of water, described as the List of lakes by area, world's largest lake and usually referred to as a full-fledged sea. An endorheic basin, it lies between Europe and Asia: east of the Caucasus, ...

. 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 (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

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

Iran Iran, officially the Islamic Republic of Iran (IRI) and also known as Persia, is a country in West Asia. It borders Iraq to the west, Turkey, Azerbaijan, and Armenia to the northwest, the Caspian Sea to the north, Turkmenistan to the nort ...

ian waters, where it mainly lives at depth. The fish are on average long and at maximum .

References

Benthophilinae Fish described in 1927 Fish of West Asia Fish of the Caspian Sea {{Gobiidae-stub