NICHE RELATIONSHIPS OF CLONAL AND SEXUAL FISH IN A HETEROGENEOUS LANDSCAPE

Abstract

We examined spatial, physiological, and morphological niche relationships in a Phoxinus eos–neogaeus gynogenetic complex of cyprinid fish in five drainages influenced by beaver (Castor canadensis) activity along the 294-km2 Kabetogama Peninsula in Voyageurs National Park of northern Minnesota. Assessment of clonal variation using “in gel” DNA fingerprinting of gynogens from three drainages indicated that all drainages contained only a single clone. When environments associated with beaver pond succession were pooled across drainages, P. eos was more abundant in active beaver ponds, while gynogens were at higher frequencies in collapsed pond and stream environments. Gynogen frequency for different successional environments classified according to drainage indicated strong variation among drainages, especially in pond environments, but a consistent pattern of increased gynogen frequency in collapsed ponds or streams. Intensive sampling within one drainage across successional beaver pond sites, physical habi...