Life Sciences Commons^™

The Effects Of Habitat Fragmentation On Fish Developmental Stability, Matthew W. Gosses

Masters Theses

In nature, organisms exist in less than ideal conditions making stress a constant factor throughout their life. These stressful environments may disturb developmental processes, causing long-term, detrimental changes to an organism expressed as bilateral variation in morphology or fluctuating asymmetry (FA). Fluctuating asymmetry has been shown to be associated with accidents during morphogenesis due to environmental factors and hence is considered a measure of developmental instability.

One environmental stressor that may affect aquatic organisms is stream habitat fragmentation. Stream habitat fragmentation is the lack of connectivity between upstream and downstream populations or sites. Stream fragmentation can create distinct patches of …

Cyclomorphosis Of Daphnia Lumholtzi In Response To Spatial Heterogeneity In Lake Taylorville, Karen K. Schnake

Masters Theses

Reservoir zonation occurs longitudinally as water enters from a stream into an impoundment. Inflow areas (or riverine zones) are typified by high flow rate and shallow depth whereas areas near the dam (lacustrine zones) characteristically have decreased flow and greater depth. In a typical reservoir, abiotic and biotic variables change somewhat predictably along a continuum from the riverine, through a transitional and into a lacustrine zone which can have a significant affect on the biota. Daphnia lumholtzi, a cladoceran which exhibits extreme cyclomorphosis, is an exotic species introduced to North America within the past twenty-five years. I examined the morphology …

Analyses Of Prairie Restorations At Rock Springs Environmental Center, Decatur, Illinois, Jennifer A. Ward

Masters Theses

Rock Springs Environmental Center was acquired in 1969 by the Macon County Conservation District. Several tracts totaling 1.6 hectares were developed as prairie restorations of varying ages on former farmland starting in 1977. During the summers of 1999 to 2001, 123 species were collected at Rock Springs. Of these, 56 species were collected within the sampling transects. The largest number of species (36 out of 56) was collected in the 1983 tract. The highest importance value of all tracts for any species was 42.6 for Andropogon gerardii. Sorensen's Index of Similarity between tracts ranged from 53.97- 72.97. The coefficient …