Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Life Sciences
The Study Of The Parasitic Fauna In Sciaenops Ocellatus, Lower Laguna Madre, Texas, Veronica Abrigo
The Study Of The Parasitic Fauna In Sciaenops Ocellatus, Lower Laguna Madre, Texas, Veronica Abrigo
Theses and Dissertations - UTB/UTPA
Parasitological investigations provide information on ecosystem health because parasite prevalence and abundance are influenced by biotic and abiotic environmental changes. This survey classified the parasitic fauna of red drum, Sciaenops ocellatus, in the Lower Laguna Madre, TX. Fish (n = 239) were collected from four study sites (May 2005 - June 2006). Parasite identification consisted of digenean and monogenean trematodes, cestodes, larval nematodes, copepods, and protozoans. Parasite prevalence and host length was positively correlated from South Bay (r=0.473), Port Isabel (r=0.533), Arroyo(r=0.314), and Port Mansfield (r=0.630). Significant differences (p<0.001) between zone and parasite prevalence from Arroyo site indicated a higher prevalence of protozoa and monogeneans and reduced prevalence of digeneans. Statistical analyses indicated the greatest difference between Port Isabel and Arroyo sites ( divided by 2= 48.195; p<0.001; df= 14), and the least difference between South Bay and Arroyo sites ( divided by 2= 20.847; p= 1.06; df= 14).
Comparison Of Soil Chemistry And Microbial Communities That Inhabit The Rhizosphere Of Native And Non-Native Grasses Of The Lower Rio Grande Valley, Jacqueline Valencia
Comparison Of Soil Chemistry And Microbial Communities That Inhabit The Rhizosphere Of Native And Non-Native Grasses Of The Lower Rio Grande Valley, Jacqueline Valencia
Theses and Dissertations - UTB/UTPA
Non-native grasses can modify the soils they invade. This study investigated microbial variation among native and non-native grasses in the Lower Rio Grande Valley. We hypothesized that rhizospheres of non-native grasses would support a higher density of microorganisms; therefore microbial communities of invasive plants would exploit more carbon sources than those of native plants. A second hypothesis stated that Streptomyces bacteria from the rhizosphere of non-native grasses would be better competitors. Samples of grasses, and soil from their respective rhizospheres were obtained in Arroyo City, TX. Results indicated a higher bacterial colony density, total activity and number of substrates utilized …