Levanidov's char or yellowmouth char (Salvelinus levanidovi)
This recently discovered anadromous char has a small range; it is found only in three river drainages of the northern part of the Sea of Okhotsk: the Yama, Takhtoyama, and Penzina Rivers.
In the Yama River, the yellow-mouth char coexist with Dolly Varden to the extent that these two species are often found in mixed schools. The numbers of yellow-mouth char are 10–20% that of the Dolly Varden.
Until recently, this fish was unknown to the scientists, although some experienced anglers were distinguishing it from the Dolly Varden char. The first materials on a new spacies were collected in 1985, and its scientific description was published in 1989.
It is not difficult to distinguish these species. A bright, fresh-from-the sea yellowmouth char looks silver-yellow, while Dolly Varden is silver-green. The sides, back, and caudal peduncle of yellow-mouth char have no red dots, but are covered by numerous oblong white or yellow spots. In broad outline, the coloration of yellow-mouth char is partly similar to that of white-spotted char, but the shape of the head and body is much more like Dolly Varden. The light spots of yellow-mouth char are about half the size of white-spotted char of the same length. The caudal and dorsal fins are covered by small gray dots, and the lower jaw is bright-yellow whereas the lower jaw of Dolly Varden is yellow-brown or red-brown.
The shape of the head and body of mature males and females of the yellowmouth char are similar (this is uncommon for other chars). Spawning colors are also similar for both sexes: gray and brown back, pink, and (or) yellow belly and throat. Compare this to typical spawning dress for Dolly Varden of bright green, blue, and red colors.