ZONATION OF A LENTIC ECOTONE AND ITS CORRESPONDENCE TO LIFE-HISTORY STRATEGIES IN FISH

A drainage channel network southeast of lake Neusiedl was investigated for fish species distribution. The network consists of relatively lar ge and permanent channels providing a stable habitat for fish and smal ler unstable channels drying up approximately once every five years. A consistent pattern of fish species distribution was found which could be interpreted with the help of a new triangular model of life histor y adaptations. In permanent channels so-called periodic and equilibriu m species prevail whereas temporary channels are inhabited by opportun istic species exclusively. In the drainage channel network a number of locally endangered fish species which have disappeared from the adjac ent lake during the last decades were found suggesting that the channe l network functions as a refuge for these fishes.