Biology Projects 2012

Habitat Preferences of the Pirate Spider, Mimetus hesperus.

Faculty Mentor - Dr. Carl Kloock

The main goal of this project is to determine the habitat preferences of Mimetus hesperus, the local representative of the spider family Mimetidae, which is known for it's unusual dietary preferences -- it eats other spiders. In order to do this we will census the spider populations of 4 different habitats at the Panorama Vista Preserve in Bakersfield California to compare abundance using a variety of measures. Participants will learn basic field ecology and spider census techniques and how to identify many of the local spider species. Spiders will also be collected for predation trials in the laboratory, where we will videotape and analyze interactions between M. hesperus and various potential prey spiders to determine prey preferences. Please be aware that because Pirate Spiders are nocturnal, this project will require significant work in the evenings, with field work frequently extending to midnight and perhaps later.

Diversity of Microcrustaceans and Detection of the amphibian pathogen Batrachochytrium dendrobatidis in ponds of the Southern San Joaquin Valley and the foothills of the Sierra Nevada (CA) by Polymerase Chain Reaction (PCR)

Faculty Mentor - Dr. Antje Lauer

Batrachochytrium dendrobatidis (Bd) is a fungal pathogen that has been identified as the cause in the massive decline of various amphibian species worldwide. Along with the decline of other species in the foothills of the Sierra Nevada due to Chytridiomycosis, the mountain yellow legged frog (Rana muscosa) is severely threatened by Bd in the higher Sierra Nevada (CA). Also, a decline of diverse microcrustacean species, which are natural predators of Bd, has been observed in some areas in the Sierra Nevada Mountains (e.g. Lake Tahoe. Microcrustaceans can also produce dormant, diapausing eggs during adverse environmental conditions that can lie dormant in sediment for decades until conditions improve and can serve as an indicator for the diversity of Microcrustaceans in the past. By investigating the water and sediment of ponds and lakes with microscopy and molecular biotechnological methods, we want to determine the presence of Bd in the watercolumn and also analyze the status quo of Microcrustaceans in the presence and past.

DNA Barcoding of the Fly Megaselia sulphurizona in California

Faculty Mentor - Dr. Paul Smith

Flies in the Family Phoridae are among the most notorious of all Diptera (two-winged flies), and have long been associated with bizarre larval lifestyles, and unrivaled cryptic diversity. Perhaps the most well-known phorid is the species Megaselia scalaris (Fig 1). Larvae of this species have been reared from nearly every type of decaying organic material, including vegetation, dead insects, dead vertebrates (including human corpses), and human food. It has caused myiasis (=invasion of living tissues) in humans by invading damaged tissues around catheter tubes, eye wounds, and surgical dressings. However, most other phorids, including the closely related species Megaselia sulphurizona, are much more poorly known. This species is distributed from Idaho West to California and as far South as Tamaulipas, Mexico. Because of the unique topography of the California landscape, which consists of many natural geographic barriers, it is possible that the Megaselia sulphurizona lineage may actually consist of more than one species. Chevron REVS-UP participants will utilize a 'DNA Barcoding' approach, which consists of sequencing a portion of the mitochondrial cytochrome I gene, to document genetic variation within and among populations of Megaselia sulphurizona. This data will be used to determine if more than one species exists in California. Participants will learn to perform: insect collecting techniques, DNA extraction, polymerase chain reaction (PCR), gel electrophoresis, and DNA sequence analysis and interpretation

Fig 1. Megaselia scalaris