Isolation Effects of Aquatic Habitat Fragmentation on Greenside (Etheostoma blennioides) and Fantail (Etheostoma flabellare) Darters

摘要: Aquatic habitat fragmentation is defined as the lack of connectivity between upstream and downstream populations can occur along two gradients, longitudinal gradient lateral gradient. The focuses on objects within stream concerned with disruption flow, which normally brought about by presence dams bridges. Fragmentation gradient, other hand, examines factors outside related to any loss or modification surrounding riparian zone. In Illinois last 100 years, habitats have become increasingly fragmented dams, pollution, zones, been an increase in channelization, wetland drainage, groundwater exploitation, most importantly, agriculture. Organisms subjected aquatic may form isolated populations, limited dispersal possibilities, leading a reduction gene flow and/or genetic variation. Intolerant species, such darters, distinct patches good differentiation populations. To determine if has had isolating effect darters system, following objectives were established: 1) estimate population size three greenside fantail 2) rate individuals patches, 3) assess degree isolation patches. Three hundred sixty-two (Etheostoma blennioides) 169 (Etheostomajl.abellare) from sites Polecat Creek Coles County, Illinois, injected elastomer marking system released back into