purcc 2012 - University of the Pacific

Poster Session Abstracts
mark-recapture studies for estimating population
sizes is that two other subspecies of Speyeria are
present in the Bay Area (S.c. comstocki and S.c.
liliana). These subspecies are difficult to
distinguish because their color patterns broadly
overlap. Thus, our study examined two
questions: 1) do S. callippe populations in the
Bay Area show any signs of reduced genetic
diversity or gene flow? And 2) do color pattern
traits used in describing subspecies correlate
with genetic diversity? To answer these
questions we analysed 884 bp of mitochondrial
DNA for 191 individuals from nine populations,
and scored each specimen for two wing pattern
traits. Our results indicated that 1) there is
striking genetic differentiation among S. callippe
populations in the Bay Area, 2) the main
endangered species population has no variation
in the analyzed gene, and 3) four mtDNA
haplogroups were identified that only weakly
correlate with the three subspecies.
Genetics of Sexual Dimorphism in an
Ostracod Crustacean, Euphilomedes
carcharodonta
Brenna Carillo-Zazueta, Logan Brodnansky,
Connie Lin, Priya Patel, Brianna Hu
Faculty Mentor: Ajna Rivera
Sexual dimorphism refers to the differences in
male and female secondary sexual
characteristics; in humans, the pathways to
sexual dimorphism is started by they presence or
absence of a Y (male) chromosome. Here we
examine a sexual dimorphism in Euphilomedes
carcharodonta, a species of ostracod
crustaceans. In this species, males and females
are genetically similar (males do not have a Y
chromosome), but differ with regards to their
eyes. Males have large multi-faceted eyes while
females have only miniscule non-image forming
eyes. The sexual dimorphism doesn’t stem from
extra genes – it actually comes from a difference
in the male and female developmental program.
Males undergo tissue duplication and gain a
second eye field which is not seen in females.
This could possibly be from differing
developmental potentials; in particular, males
and females may turn on different sets of genes
in their nervous system cells. To begin to
understand how males can grow eyes without
additional genetic information, we cloned and
looked at the sequence of several genes known to
be involved in eye development. In the future,
we will also compare gene expression levels
(how much a particular gene is turned on) in
male and female eyes.
Comparing Total Precipitation for Vernal
Pools in Wet and Dry Seasons
Minhchau Dinh
Faculty Mentor: Dr. Stacy Luthy
Vernal pools, also referred to as temporary pools
or ephemeral pools, are surface pools on
impervious land substrates leftover from
precipitation. These temporary pools appear
during rainfall in winter and spring, and dry up
in summer and fall. Throughout this cycle,
vernal pools support numerous endemic plant
and animal species, many of which are
endangered, such as the federally and state
protected fairy shrimp and its three species. For
this research I took pool samples from four sites
near Prairie City, CA from November 2010 to
April 2012 that included three types of
crustacean: copepods, daphnia, and fairy shrimp.
These crustaceans lay resistant eggs (cysts) when
the pools are wetted that will hatch during the
next pool season. Research has shown cysts
hatch proportionally to their chances of survival
and that vernal pool depth is positively correlated
with species richness. The length of inundation
of these species is critical to their success, as
some species need longer ponding periods to
fully develop. Longer ponding periods depend
on total precipitation, storm intensity and pattern,
and land topography. In Northern California, the
winter of 2010-2011 was classified as wet, but
the next year (winter 2011-2012) was extremely
dry. This scenario not only led to fewer vernal
pools in 2011-2012, but also pools with
shallower depth and shorter inundation period. I
analyzed total precipitation between the 2011
and 2012 vernal pool seasons to observe how
total precipitation, storm intensity, and rain
patterns affect the life and longevity of vernal
pools.
Effects of Range and Frequency on
DIDSON Measurement Accuracy
Alec Follmer, Gwen Alldredge
Faculty Mentor: Dr. Stacy Luthy
The DIDSON Sonar is a multi-beam acoustic
camera that produces near video quality images
in two frequencies (low-1.1MHz and high-
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