Ohrid trout

Ohrid trout
Ohrid trout
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Salmoniformes
Family: Salmonidae
Genus: Salmo
Species: S. letnica
Binomial name
Salmo letnica

(Karaman, 1924)

Ohrid trout[1][2] or the Lake Ohrid brown trout[3] (Salmo letnica) is an endemic species of trout in Lake Ohrid and in its tributaries and outlet, the Black Drin river, in the Republic of Macedonia and Albania in the Balkans. Locally the fish is known as Ohridska pastrmka in Macedonian and koran/korani in Albanian.

Contents

Taxonomy

Ohrid trout is part of the brown trout complex, and therefore its taxonomic status is controversial.[3] It has however been deemed to be genetically sufficiently distinct to be regarded as a distinct species for conservation arguments.[4]

Subdivision of the Ohrid trout

Within the Ohrid trout itself, up to four intralacustrine forms have been separated, which are treated as distinct species in the FishBase and by the IUCN. Morphological or molecular data so far do not support this division however.[2][3][4] These forms are characterized by different breeding areas and different breeding times, by which they are thought to be reproductively isolated from each other. The four forms or species include:

  • Salmo balcanicus, breeds in the outlet of the lake in its NW end, in October–January; possibly extinct.
  • Salmo lumi, breeds in January–February in the tributaries of the lake.
  • Salmo aphelios, breeds in May–July near springs of the eastern shore of the lake.
  • Salmo letnica, breeds in January–February.[1]

In addition to the Ohrid trout, Lake Ohrid has another endemic and truly distinct salmonid, Salmo ohridanus.[3]

Fisheries and gastronomy

The Ohrid trout is a specialty in Macedonian and Albanian gastronomy; it is used for soups and other dishes. It tastes like a brown trout crossed with an atlantic salmon.

In recent years extensive fishing has driven the Ohrid trout to the verge of extinction,[5] though there are several conservation activities. A fishing ban has been imposed by the Government of Macedonia, since 2004 and until 2014. In Albania, since 2003 the state law on fisheries prohibits fishing during the spawning period only,[6][7] but no restrictions exist for the rest of the year, and the fish population is still dwindling due to illegal fishing and overfishing.[8]

The Ohrid trout is depicted on the reverse of the Macedonian 2 denars coin, issued in 1993.[9]

Vlasina Lake

The Ohrid trout has been successfully translocated to and bred in the Vlasina Lake in Serbia, during the 1950s and 1960s; current population status is unknown.[10] The first lots of Ohrid trout (Salmo trutta (m) lacustris L.) were introduced in the newly formed Vlasina reservoir in 1953, when around 500,000 fish were transferred. The Ohrid trout was the dominant species in the lake at the time, but then lost its position during the 1980s, because the breeding program was discontinued, and because of failure of natural spawning due to water level variations related to working schedules of the hydroelectric plant, Vrla. Some fish still spawn successfully in the flooded tributaries of the lake. During the 1990s bleak (Alburnus alburnus) and roach (Rutilus rutilus) from Lake Ohrid were introduced into Vlasina as food for the Ohrid trout. Also a yearly program of artificial spawning and conservation efforts started.[11]

References

  1. ^ a b Froese, Rainer, and Daniel Pauly, eds. (2010). "Salmo letnica" in FishBase. February 2010 version.
  2. ^ a b Crivelli, A.J. 2006. Salmo letnica. IUCN Red List of Threatened Species. Version 2010.1 Downloaded on 20 May 2010.
  3. ^ a b c d Lake Ohrid trouts Balkan trout restoration group. Downloaded on 20 May 2010.
  4. ^ a b Suśnik S, Snoj A, Wilson I, Mrdak D, Weiss S (2007) Historical demography of brown trout (Salmo trutta) in the Adriatic drainage including the putative S. letnica endemic to Lake Ohrid. Molecular Phylogenetics and Evolution 44(1), 63-76. (abstract)
  5. ^ "Fossil Trout" Faces Extinction in Balkans, Experts Warn National Geographic News (2003)
  6. ^ http://www.monstersandcritics.com/science/features/article_1412208.php/Fishing_ban_finally_gives_Ohrid_trout_a_lease_on_life
  7. ^ http://www.biogeosciences-discuss.net/7/5347/2010/bgd-7-5347-2010.pdf [page 19 of 36 (type 5365)]
  8. ^ ALBANIA PILOT FISHERY DEVELOPMENT PROJECT, page 2
  9. ^ National Bank of the Republic of Macedonia. Macedonian currency: Coins in circulation. – Retrieved on 30 March 2009.
  10. ^ Vlasinsko jezero www.loviribolov.org
  11. ^ Vlasinsko Jezero solair.eunet.rs