The Caspian kutum (''Rutilus kutum'') or Caspian white fish is a member of the family

Cyprinidae Cyprinidae is a family of freshwater fish commonly called the carp or minnow family. It includes the carps, the true minnows, and relatives like the barbs and barbels. Cyprinidae is the largest and most diverse fish family and the largest ve ...

from

brackish water Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

habitats 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 A ...

and from its freshwater tributaries. It is typically a medium-sized fish, reaching 45–55 cm in length, rarely 70 cm, and weighing up to 4.00 kg, rarely 5.00 kg. It used to be very common and was harvested commercially. The population seems to have collapsed due to

overfishing Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing fish stock), resulting in t ...

and

marine pollution Marine pollution occurs when substances used or spread by humans, such as industrial, agricultural and residential waste, particles, noise, excess carbon dioxide or invasive organisms enter the ocean and cause harmful effects there. The major ...

. Its flesh and

roe Roe ( ) or hard roe is the fully ripe internal egg masses in the ovaries, or the released external egg masses, of fish and certain marine animals such as shrimp, scallop, sea urchins and squid. As a seafood, roe is used both as a cooked in ...

are enjoyed as food, and highly prized in the Gilan and Mazandaran provinces in

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 ...

Feeding

The main food items are mollusks, shrimp,

amphipod Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods range in size from and are mostly detritivores or scavengers. There are more than 9,900 amphipod species so far descri ...

s, and crabs. Larvae and fry feed on

rotifer The rotifers (, from the Latin , "wheel", and , "bearing"), commonly called wheel animals or wheel animalcules, make up a phylum (Rotifera ) of microscopic and near-microscopic pseudocoelomate animals. They were first described by Rev. John H ...

s, minute forms of

cladoceran The Diplostraca or Cladocera, commonly known as water fleas, are a superorder of small crustaceans that feed on microscopic chunks of organic matter (excluding some predatory forms). Over 1000 species have been recognised so far, with many more ...

diatom A diatom ( Neo-Latin ''diatoma''), "a cutting through, a severance", from el, διάτομος, diátomos, "cut in half, divided equally" from el, διατέμνω, diatémno, "to cut in twain". is any member of a large group comprising se ...

algae, and larvae of

copepod Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic (inhabiting sea waters), some are benthic (living on the ocean floor), a number of species have ...

Population

Three populations (one autumn and two spring populations) were found in the rivers of Iran; a freshwater form exists in the South Caspian.

Distribution

Caspian kutum is endemic to the Caspian Sea. It is distributed from the mouth of the Volga River up to the Miankaleh Peninsula. Main aggregations are confined to the southwestern part of the sea adjacent to the Anzali and Qizilchay Bays. On the eastern coast, it occurs in the

Atrek The Atrek ( fa, اترک, ku, Etrek, tk, Etrek derýasy), also known as the Attruck, Atrak, and Etrek, is a fast-moving river which begins in the mountains of north-eastern Iran (), and flows westward draining into the south-eastern corner of th ...

estuarine areas and in the Iranian waters.

Behavior

This species lives in small schools in deep water, but spawns in shallow water in the tributaries in April–May. The eggs are laid among weeds or over gravel, and hatch in about 10 days. They become sexually mature in 3–5 years. Resilience of this species is low. Minimum population doubling time is 4.5 – 14 years. The fish is also called Caspian white fish and Caspian roach, and is known as ''kutum'' in Russian, ''kütüm'' in Azerbaijani, and ''māhi sefid'' in Persian.Kuliev Z.M
''Rutilus friesii kutum'' (Kamensky, 1901)
caspianenvironment.org

References

{{Taxonbar, from=Q2637892 Fish described in 1901 Fish of Central Asia Fish of Russia Fish of the Caspian Sea Cyprinid fish of Asia

kutum Kutum is a town in the Sudanese state of North Darfur. It lies northwest of the state capital, Al-Fashir. The town is located along a wadi and therefore also known as Wadi Kutum. It lies north along the Marrah Mountains; the Kutum volcanic fi ...

Feeding

Population

Distribution

Behavior

See also

References