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Life Cycle

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Recorder
Rainer Froese
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Biology

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The adults spawn in the lake proper at a depth range of 0.5 to 3 m, over fine gravel. Two spawning stocks are known: one spawns in the northwestern corner of the lake from the beginning of November till the end of December; the other spawns at the southeastern corner, from the middle or the end of January till the end of March. This fish approaches the coast twice a year: from April till July and from October till December. In mid winter and at the end of summer, it leaves the coasts to stay at greater depth. Adults feed exclusively on sand hoppers (Amphipoda) (Ref. 593).
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Importance

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fisheries: commercial; gamefish: yes
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Sevan trout

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The Sevan trout (Salmo ischchan) is an endemic fish species of Lake Sevan in Armenia, known as ishkhan (իշխան, pronounced [iʃˈχɑn]) in Armenian. It is a salmonid fish related to the brown trout.

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Gegharkuni (Salmo ischchan gegarkuni)

The fish is endangered, because various competitors were introduced into the lake during the Soviet period, including common whitefish (Coregonus lavaretus) from Lake Ladoga, goldfish (Carassius auratus) and narrow-clawed crayfish (Astacus leptodactylus); and because of lake level change. On the other hand, the Sevan trout itself has been successfully introduced to Issyk Kul lake in Kyrgyzstan.[1]

A resolution by Armenia's Council of Ministers in 1976 stopped the commercial fishing of Sevan trout and organized Sevan National Park. The fish are nowadays also reared in hatcheries.[2]

The Sevan trout has four[2][1] (or two[3]) distinct strains differing in their breeding time and place, and growth rate:

  • winter bakhtak (Salmo ischchan ischchan)
  • summer bakhtak (Salmo ischchan aestivalis)
  • gegharkuni (Salmo ischchan gegarkuni)
  • bojak (Salmo ischchan danilewskii).

The winter bakhtak is the largest form and can grow to considerable size, up to 90 cm and 15 kg. It breeds within the lake.[1] The summer bakhtak is smaller (<50 cm), and breeds naturally both in rivers and within lake near river mouths.[2] Gegharkuni is a migratory form that naturally breeds exclusively in rivers; it also feeds on plankton in addition to benthos.[2] Bojak in turn is a dwarfed form that breeds within the lake in the winter, and does not exceed 33 cm and 0.25 kg.[1]

Water level regulation has been destructive for sevan trout reproduction. Currently, the summer bakhtak and gegharkuni are mainly propagated by hatcheries. The winter bakhtak and bojak may be extinct within the lake.[2]

From a study of historical samples, the four strains or forms are not diagnosable by their mitochondrial DNA sequences. As a whole, the Sevan trout is phylogenetically very close to the Caspian trout, within the brown trout complex.[4]

References

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Sevan trout: Brief Summary

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The Sevan trout (Salmo ischchan) is an endemic fish species of Lake Sevan in Armenia, known as ishkhan (իշխան, pronounced [iʃˈχɑn]) in Armenian. It is a salmonid fish related to the brown trout.

 src= Gegharkuni (Salmo ischchan gegarkuni)

The fish is endangered, because various competitors were introduced into the lake during the Soviet period, including common whitefish (Coregonus lavaretus) from Lake Ladoga, goldfish (Carassius auratus) and narrow-clawed crayfish (Astacus leptodactylus); and because of lake level change. On the other hand, the Sevan trout itself has been successfully introduced to Issyk Kul lake in Kyrgyzstan.

A resolution by Armenia's Council of Ministers in 1976 stopped the commercial fishing of Sevan trout and organized Sevan National Park. The fish are nowadays also reared in hatcheries.

The Sevan trout has four (or two) distinct strains differing in their breeding time and place, and growth rate:

winter bakhtak (Salmo ischchan ischchan) summer bakhtak (Salmo ischchan aestivalis) gegharkuni (Salmo ischchan gegarkuni) bojak (Salmo ischchan danilewskii).

The winter bakhtak is the largest form and can grow to considerable size, up to 90 cm and 15 kg. It breeds within the lake. The summer bakhtak is smaller (

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