Kezenoi Am Trout

Distinguished from congeners in Caspian Sea basin by having the following unique characters: 16-21 short and broad gill rakers, without denticles, in large individuals sometimes slightly expanded at tip; maxilla not reaching posterior margin of eye; and bright coloration comprising of 10-30 relatively large (6-7 mm in diameter) carmine red spots above lateral line, small black spots on back, red spots on dorsal, upper caudal lobe, and adipose fins (Ref. 59043).

Inhabits mountain lake (Lake Kezenoi-am) with altitude of 1870 m above sea level, with a maximum depth of 74 m, temperature about 5° C below 20 m and 5-18° C in upper layers in summer, covered by ice in winter, high oxygen concentrations down to bottom throughout the year and low plankton density. This was the only fish inhabiting the lake prior to the introduction of Gobio holurus and Squalius cephalus. Young juveniles feed predominantly on gammarids, chironomid larvae; larger juveniles and adults prey on molluscs, benthic invertebrates and fry; largest individuals are mostly piscivorous, especially since the introduction of Gobio holurus. Spawns in lake, close to underwater springs. Large-sized individuals probably undertake migration to tributaries. Spawning extends over almost entire year. Threatened due to the introduction of Squalius cephalus, which feeds on its fry (Ref. 59043).

Salmo ezenami is a critically endangered freshwater salmonid fish, endemic to Lake Kezenoi-Am (Lake Eizenam) in Northern Caucasus.

The only native occurrence, in Lake Kezenoi-Am in Chechnya at the border of Dagestan, is in a cold alpine lake (area 2.4 km2, maximum depth 74 m, 1870 m altitude). In addition, the species has been introduced to another lake in Dagestan, Lake Mochokh, probably successfully.

Salmo ezenami used to be the only fish species in Lake Kezenoi-Am. However, two other species, the European chub and Caspian gudgeon have been introduced, and present a threat by eating the fry of Salmo.

Salmo ezenami spawns in the lake, close to underwater springs. Adult fish also probably migrate to tributaries. There are separate small-sized (adults 160–260 mm) and large-sized forms (380–1130 mm). Young prey on gammarids and chironomids; adults also eat molluscs and fishes, after the introduction of nonnative species.