Browsing by Author "Kranzfelder, Petra"

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    Comparison of emergence and taxonomic composition of chironomidae (Insecta: diptera) in Tortuguero National Park, Costa Rica.
    (2012-01) Kranzfelder, Petra
    Traditional methods of collecting aquatic macroinvertebrates can be time consuming and expensive. One efficient form of sampling involves collection of surface floating pupal exuviae (SFPE) of a group of aquatic flies of the family Chironomidae. Previous studies have shown the efficacy of the SFPE collection technique to determine chironomid taxonomic composition and temporal organization in small streams of northwestern Costa Rica. However, the methodology has never been employed in a Neotropical brackish water setting and its efficacy was unknown in this context. The primary goal of this study was to test the SFPE method in a Neotropical brackish water setting and to expand the knowledge base of chironomid taxonomy and ecology in Costa Rica. The objectives of this research were to determine the economy of the SFPE method for studies in Neotropical brackish waters and the variability of Chironomidae emergence and taxonomic composition. Collections of chironomid SFPE were made in the brackish water estuary, Laguna del Tortuguero, and freshwater stream, Quebrada, in Tortuguero National Park, Costa Rica on seven consecutive days during both the dry and wet seasons. The SFPE method appears to be a reasonably economical method for sampling Chironomidae in Neotropical brackish waters and it is successful in detecting spatial differences in emergence between sites in the dry and wet season. The results indicate that Chironomidae SFPE sampling could be employed as part of a rapid biomonitoring program for monitoring water and sediment quality in Tortuguero National Park, Costa Rica. Generally, these data will expand the knowledge base of Neotropical Chironomidae taxonomy and ecology, which will facilitate entomological and aquatic ecology research and teaching in Latin America.
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    Cumulative Effects of Coastal Watershed Land Use on Chironomidae (Insecta: Diptera) Communities of Neotropical Estuaries in Costa Rica
    (2017-07) Kranzfelder, Petra
    Chironomidae assemblages are likely to provide a useful measure of biotic integrity in Neotropical estuaries of Costa Rica, which lack an intensive estuarine bioassessment tool to support environmental monitoring. However, little is known about chironomid communities in these estuaries and the cumulative effects of watershed land use on chironomid communities have not been studied. The purpose of this dissertation was to (1) quantify land cover change of six watersheds on the Caribbean coast of Costa Rica between 2001 and 2014, (2) describe all steps of the Chironomidae surface-floating pupal exuviae method in detail, including sample collection, laboratory processing, slide mounting, and genus identification, (3) investigate Chironomidae species diversity of nine estuaries across a land use gradient on the Caribbean coast of Costa Rica, (4) compare the relative effectiveness of five different DNA extraction protocols and direct PCR in isolation of DNA from chironomid pupal exuviae, and (5) assess the efficiency of using standard DNA barcoding for species identification of chironomid pupal exuviae. I found that watershed-scale land use analyses showed agricultural expansion and deforestation in watersheds on the northeastern coast and secondary forest regrowth on the southeastern coast of Costa Rica. I identified 228 morphospecies and 70 genera from 17,071 Chironomidae surface-floating pupal exuviae collected from nine Neotropical estuaries and that a Chironomidae Index of Biotic Integrity successfully discriminated estuaries with differing degrees of stress across a land use gradient. I extracted genomic DNA from 61.2% of 570 sampled pupal exuviae. The NucleoSpin® Tissue XS Kit, DNeasy® Blood and Tissue kit, and QuickExtract™ DNA Extraction Solution provided the best results in isolating DNA from single pupal exuviae. A total of 36.3% of 190 sampled pupal exuviae resulted in high-quality sequences for Costa Rica, but none matched known species. This knowledge is important if these aquatic communities are to be used more effectively in future biological monitoring, conservation, and integrated water resource management of Neotropical estuaries.
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    Diversifying discussions: How do we facilitate talking about biology in our classrooms?
    (2019) Melloy, Marin; Mohammed, Sagal; Kranzfelder, Petra; Bankers-Fullbright, Jennifer L.; García-Ojeda, Marcos E.; Warfa, Abdi
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    Teacher-Initiated Discourse Moves in Reformed Undergraduate STEM Learning Environments
    (2018) Vaghani, Vinit; Mohammed, Sagal; Kranzfelder, Petra; Bankers-Fulbright, Jennifer; Garcia-Ojeda, Marcos; Warfa, Abdi