Matz Indergard, Paul Spruell, and Fredrich Govedich, Southern Utah University
Life Sciences
Dispersal of organisms allows them to colonize new habitats and may buffer against extirpation due to localized catastrophic events. For organisms inhabiting ephemeral environments, dispersal can be challenging, as suitable habitat is often small, isolated spatially, and unpredictable temporally. Fairy shrimp are small invertebrates that occupy ephemeral freshwater pools filled by rainfall. Fairy shrimp produce resting (resistant) eggs when conditions are not favorable. Upon the return of supportive conditions, these eggs will then hatch. Little is known about the methods of dispersal used by fairy shrimp. However, it has been suggested that the resting eggs are the most likely life stage to provide dispersal opportunities. We examined two proposed methods of egg dispersal for fairy shrimp (Brachinecta sp) from a series of ephemeral pools just north of Three Peaks near Cedar City, Utah. We hypothesized that dispersal could be attributed to prevailing winds or water runoff, which would disperse eggs in a direction corresponding to prevailing wind patterns or to outflow following the surface gradient. To conduct our test we established three reference points equally spaced in the linearly arrayed series of pools. We then collected soil samples at randomly determined locations around these center points to form an overlapping radial grid. We then added purified water to each of our samples and hatched any shrimp eggs that were present in the sediment. We then mapped the overall concentrations of shrimp in our sampling area. Results to date do not reveal an obvious pattern with prevailing wind direction and dispersal.