Markierungsversuche an Bach- und Regenbogenforellen im Bodensee als Beitrag zur systematischen Eingliederung von Forellen

Nearly 900 tagged trouts (brown and rainbow trouts) have been exposed at a distance of 300 m and 1,5–4,5 km from the shore. In the first case the recapture was more favour-able. According to the series 6 to 20% brown trouts and only 1% rainbow trouts were recaptured. The greater part has been caught in the lake; only from October to May the reports came from the rivers. Brown and rainbow trouts lost in the lake their reddish spots or the rainbrowstripe and became silver. The growth is nearly as quick as in the lake trout. After a critical review of our own results and those found in literature we came to the conclusion that there are no morphological differences between brown and lake trouts. It may be that there are genetically fixed differences in the biological-physiological behaviour. But even in this case a classification inSalmo trutta morpha lacustris andS. t. m. fario could not be justifiable—for practical reasons only-because, independantly, in the single lakes the development of lake trouts from populations of brown trouts has happened polyphyletically. Also, for genetically different populations, normally no classifications in subspecies are made. Probably, the difference in the colour and growth-easily striking the eye-misdirects to assume the form ‘morpha lacustris’.