The Caspian kutum ( Rutilus kutum) or Caspian white fish
Taxonomy
The Caspian kutum was first formally described in 1901 as
Leuciscus frisii kutum by Sergei Nikolaevich Kamensky with its type locality given as the southern Caspian Sea and its tributaries.
This species is now classified within the genus
Rutilus in the
subfamily Leuciscinae of the family
Leuciscidae.
However, authorities consider that this species is a
subspecies of the Black Sea roach (
Rutilus frisii).
Etymology
The Caspian kutum belongs to the genus
Rutilus, a name which means "red, golden red and reddish yellow" and is an allusion to the red colour of the fins. The specific name,
kutum is the
Russian language vernacular name for this species.
The fish is also called Caspian white fish and is known as kutum in Russian, kütüm in Azerbaijani, and māhi sefid in Persian language.
Description
The Caspian kutum is very similar to the Black Sea roach. It can attain a length of , rarely up to and a weight of , rarely .
Distribution
The Caspian kutum is found along the western and southern coast of the Caspian Sea between Kura to
Gorgan Bay, it has been
Local extinction from the
Volga.
[
]
Biology
The Caspian kutum are predators of benthic organisms, mostly molluscs and other aquatic invertebrates such as insect larvae and crustaceans. They are sexually mature from 4 years old and may live as long as 12 years. They begin their spawning migration from the Caspian Sea into rivers when the water temperature reaches 9–10°C, typically in mid to late February. The spawning migration peaks from mid-March to early April when the water is at 12.3–12.6°C. The eggs are laid in reeds and among Nymphaeaceae at the outflows of rivers when the temperature reaches 13–15°C in late March to mid April. The fecundity of these fishes is dependant on size and varies between 30,000 and 300,000 eggs per female. From mid-May the larvae start a slow migrationtowards the Caspian Sea.[
]
Fishing
The Caspian kutum is an important target for fisheries, particularly in the southern Caspian Sea where the stocks are supported by aquaculture and releases.[
]
See also
