The dwarf sturgeon, little shovelnose sturgeon, or small Amu-Darya shovelnose sturgeon (Pseudoscaphirhynchus hermanni) is a species of fish in the family Acipenseridae. It is found in Turkmenistan, Uzbekistan and probably in Tajikistan.
Population
Pseudoscaphirhynchus hermanni population is recorded to be a rare species. There are few recordings of this species being caught, but there are accusations that fishermen are unknowingly catching them. The population trend of this species is decreasing. Pseudoscaphirhynchus hermanni is being negatively affected due to dams, poaching, water extraction, irrigation, and high levels of water pollution including mineral fertilizers, pesticides for cotton agriculture, and drainage waste. More survey work on this species is needed to determine the status of their population. Overall this species is recorded to be a critically endangered species.[1]
Diet
Pseudoscaphirhynchus hermanni has a diet of small aquatic invertebrates.
Pseudoscaphirhynchus hermanni has been recorded reaching a maximum length of 27 centimeters or 10.63 inches. The maximum reported weight of this species is 51 grams or 0.11 pounds. The oldest reported age of this species is six years old. This species is considered to be potamodromous. This species is also recorded to be sensitive to chemicals in the water.[5] One of the specific features of Pseudoscaphirhynchus hermanni is the crease on the external edge of the pectoral fin.
Environment
Pseudoscaphirhynchus hermanni is recorded to live in freshwater or slightly salty environments within a demersal depth range. This species lives in a temperate climate.[5][6]
Common names
The common names of Pseudoscaphirhynchus hermanni in various languages include the following:
Video of Pseudoscaphirhynchus hermanni and the both forms of Pseudoscaphirhynchus kaufmanni in one pool for comparison (in Pseudoscaphirhynchus hermanni the crease on the external edge of pectoral fin is well seen) - the lower stream of Amu Darya River (Khorezm Province, Uzbekistan):https://www.youtube.com/watch?v=lio_vxQ7yG8&t=2s
L. S. Berg, Freshwater Fishes of the USSR and the neighboring countries, Part I, the 4th Edition, Zoological Institute of Academy of Sciences of the USSR, Publishing House of Academy of Sciences of the USSR, Moscow-Leningrad 1948 - basic data on Pseudoscaphirhynchus hermanni (pages 105 and 108) and picture of the crease on the external edge of pectoral fin (page 109):http://life-on-earth.ru/images/Plesheevo1/Berg_Fishes_of_the_USSR_Part1.PDF