Longfin char (Salvethymus svetovidovi)
The scientific name of the genus — Salvethymus — was created out of the words Salvelinus (char) and Thymallus (grayling).
The long-fin char is a small char with a short head and mouth, and the lower jaw protruding forward, a short humpy snout, small eyes and high, flattened body with very long fins (especially paired fins). The lobes of the forked caudal fin are rounded. There are powerful fang-shaped teeth on the jaws, palatine bones and tongue; there are no teeth on the vomer. The head and torso are dark on top, the sides of the body and the belly have golden tint. The fins are black; the tips of the unpaired fins are milky white. On the body there are many small spots that are greenish on the back and white on the sides. The spawning fish become almost black.
The long-fin char is a genus relative to the present-day chars; it differs from the chars by many morphological features; the karyotype of new genus is not similar to any char.
The long-fin char dwell deep in the lake hollow throughout the year. The biggest concentrations were observed at 50–110 m. This fish was found even in the deepest part of the lake (176 m). It does not often come to the lake shores, but young individuals have been found in the schools of adult small-mouth char in shallow places.
Long-fin char feed on zooplankton (copepods) and sometimes on freshwater shrimp. This is a unique ecological niche for salmonid fish – deepwater plankton-feeder. The long-fin char is a slow-growing fish: the biggest specimen was 30 cm long, and its age was 30 years!
The maturation occurs at the age of 14-15 years with the length of 15-16 cm. the fertility is low: 170-1000 eggs (average 640). This fish is never large and grows very slowly – the largest individual, only 33 centimeters long, was 30 years old!
The species is listed in the “List of endangered fish of the world” and in the Red Book of the Russian Federation.