Writing in Biology

The feeding pattern of spiders reveal a lot about their metabolism, locomotive behavior, predatory instincts, and ecological impact on surrounding biomass. Long-term starvation affects all of these variables to different extent in different species. However, it is not well-understood how short-term starvation may affect spiders’ feeding behavior and movement. In this proposal, we aim to assess the impact of short-term starvation on feeding behavior and movement of cellar spiders and wolf spiders, under various environmental stressors and in presence of competition. Spiders (n=3) will be placed in individual clear containers and starved for either a 3-day or 7-day period, and their behavior will be contrasted with their satiated counterparts. To understand the combined effect of environmental stressors and food deprivation, some cellar spiders will be placed in cold (18 C) or hot (30 C) environments. The difference in feeding pattern between male and female wolf spiders after short-term starvation will be recorded. And, to assess the impact of competition after starvation, multiple cellar spiders will receive a limited amount of food. All data should be collected in a qualitative manner, outside of feeding rate and mortality of spiders ,and will be analyzed in comparison to the control group of not-starved spiders. Understanding the impact of short-term starvation on spiders’ predatory and locomotive behavior will broaden our knowledge of their metabolic activities and will help us better utilize them for pest control.

Our experiment studies cellar spider web weight and production in relation to the temperature of the spider's surrounding environment.  This experiment can be used as a microcosm for Earth to show the effects that climate change could have on the survival and location of cellar spiders. Globally, species are expected to shift locations in response to climate change.  When the region an organism resides in becomes too hot or too cold for the organism to thrive, the organism will move towards the poles or equator accordingly to adjust for the change in temperature. If the area becomes too hot to support that species, the members of the species will generally migrate gradually towards the poles in order to stay in an environment that suits their temperature needs.  If the area becomes too cold to support that species, the members of that species will gradually migrate to a warmer area, which is generally towards the equator. Most of the Earth is expected to warm over the next several decades, but there are some areas on Earth that are expected to get colder.

By generating a Lokta-Volterra model and analyzing the results of this competition, the outcome of the competition between C. maculate (Species 1) and E. Civile (Species 2) can be determined as reaching stable equilibrium. This outcome will be most likely to occur based on the data points present in the model which in turn generates isocline 1, isocline 2, and four separate arrow sets in the respective zones that all point to a central, stable equilibrium point. In Zone 1, below both of the isoclines, the populations of both competing species will increase. In Zone 2, which is found above Species 2 (E. Civile) isocline and below Species 1 (C. maculate) isocline, the population size of Species 1 will increase and the population size of Species 2 will decrease. In Zone 3, which is found above both species isoclines the population of both Species 1 and Species 2 will decrease. In Zone 4, which is found above Species 1 isocline and below Species 2 isocline the population size of Species 1 will decrease and the population size of Species 2 will increase.

By generating a Lokta-Volterra model and analyzing the results of this competition, the outcome of the competition between C. maculate (Species 1) and E. Civile (Species 2) can be determined as reaching stable equilibrium. This outcome will be most likely to occur based on the data points present in the model which in turn generates isocline 1, isocline 2, and four separate arrow sets in the respective zones that all point to a central, stable equilibrium point. In Zone 1, below both of the isoclines, the populations of both competing species will increase. In Zone 2, which is found above Species 2 (E. Civile) isocline and below Species 1 (C. maculate) isocline, the population size of Species 1 will increase and the population size of Species 2 will decrease. In Zone 3, which is found above both species isoclines the population of both Species 1 and Species 2 will decrease.

By generating a Lokta-Volterra model and analyzing the results of this competition, the outcome of the competition between C. maculate (Species 1) and E. Civile (Species 2) can be determined as reaching stable equilibrium. This outcome will be most likely to occur based on the data points present in the model which in turn generates isocline 1, isocline 2, and four separate arrow sets in the respective zones that all point to a central, stable equilibrium point. In Zone 1, below both of the isoclines, the populations of both competing species will increase. In Zone 2, which is found above Species 2 (E. Civile) isocline and below Species 1 (C. maculate) isocline, the population size of Species 1 will increase and the population size of Species 2 will decrease. In Zone 3, which is found above both species isoclines the population of both Species 1 and Species 2 will decrease.

By generating a Lokta-Volterra model and analyzing the results of this competition, the outcome of the competition between C. maculate (Species 1) and E. Civile (Species 2) can be determined as reaching stable equilibrium. This outcome will be most likely to occur based on the data points present in the model which in turn generates isocline 1, isocline 2, and four separate arrow sets in the respective zones that all point to a central, stable equilibrium point. In Zone 1, below both of the isoclines, the populations of both competing species will increase. In Zone 2, which is found above Species 2 (E. Civile) isocline and below Species 1 (C. maculate) isocline, the population size of Species 1 will increase and the population size of Species 2 will decrease.

By generating a Lokta-Volterra model and analyzing the results of this competition, the outcome of the competition between C. maculate (Species 1) and E. Civile (Species 2) can be determined as reaching stable equilibrium. This outcome will be most likely to occur based on the data points present in the model which in turn generates isocline 1, isocline 2, and four separate arrow sets in the respective zones that all point to a central, stable equilibrium point.

By generating a Lokta-Volterra model and analyzing the results of this competition, the outcome of the competition between C. maculate (Species 1) and E. Civile (Species 2) can be determined as reaching stable equilibrium. This outcome will be most likely to occur based on the data points present in the model which in turn generates isocline 1, isocline 2, and four separate arrow sets in the respective zones that all point to a central, stable equilibrium point.

Previous studies show that oxidative stress is both necessary and sufficient for triggering ISC proliferation. However, the mechanisms behind oxidative stress and mitogenic signals are relatively poorly understood. This figure displays that TRP1 and RyR genes are required for ISC self-renewal but not differentiation. MARCM clones are analyzed along with their control counterparts 10 d after clone induction. The bar graph represents number of cells per clone, 5 guts were analyzed per genotype, and data shows the average + SEM. MARCM, or mosaic analysis with a repressible cell marker, relies on recombination during mitosis  mediated by the Flp-FRT system. Flp-FRT is a site-directed recombination technology. (FRT= flippase recognition target). According to the researchers, the cells still proliferate but not a lot of them are stem cells. So, these genes TRP1 and RyR are recognized to be important for ISC self-renewal but not for differentiation. 

Three cellar spiders were placed in separate  clear containers to allow observation without interfering with spider’s predation. Each spider was then placed in three varying temperatures of 29℃, 22℃, and 14℃. Prey were selected according to size because cellar spiders rely on the complicated matrix of their web to entangle their prey as the web is not adhesive.  Prey were observed to be consumed in time intervals of hours after insertion to the spider habitat. No energy was used to coax the fruit fly into the web and the spider ate the 2 flies out of the 3.