琶琵湖水系に生息する特殊斑紋のイワナSalvelinus leucomaenis

抄録

In Onaga-tani (Fig.1.B) and Sutani River (Fig.1.C) in the upper reaches of Ane River and Echi River of Lake Biwa water system, the author collected specimens which seem to be the char, Salvelinus leucomaenis having zigzag marks, instead of parr-marks, on their body side.Since such specimens are not known, the author describes their form (Table 1), localities, and habitats.
Specimens with atypical color patterns may be variation of Salvelinus leucomaenis (Pallas), and not hybrids between other salmonids and the char.Japanese name “6 nagaremon -iwana” is proposed for these variants.