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There’s a Fungus Among-us. Termite research by Claire Fuller And her trusty helpers: Beatriz, Rebecca, Jennifer, and Clarity. Introduction/Research:.
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There’s a Fungus Among-us Termite research by Claire Fuller And her trusty helpers: Beatriz, Rebecca, Jennifer, and Clarity
Introduction/Research: Termites grow fungus after a few days in agar. Due to either different exposure rates or inhibition rates, some combinations of different castes grow fungus faster than others. Our experiment attempts to test to find out whether soldier secretions inhibit fungal growth and whether worker’s foraging tendencies increase their exposure to spores, decreasing the amount of time it will take for them to grow fungus.
Hypothesis: • Soldiers inhibit fungal growth with their secretions. • Workers contain a larger amount of spores due to their foraging tendencies and have fewer days until fungal growth is evident. • Different types of fungus grow on different termite castes.
Methods: • Collected both workers and soldiers from 11 termite colonies. • Set up various combinations of workers and soldiers. • Once the combinations were established, the termites were placed in microfuge tubes and smashed with sterile tools. • The smashed termites were then smeared on agar in sterile test tubes. • The rims of the test tubes were sterilized with flame and the lids were left slightly open to allow growth.
Observations: • Every day for five days after the initial setup of the tubes, we monitored and recorded any visible sign of fungal growth. • The growth of both slime-mold and filamentous fungus were observed. • We quantified fungal growth by counting the number of each type of fungal colony present on the agar. We also noted size, color, location, and merging of colonies (if applicable). • Our findings were recorded on data sheets with the date of collection, dates and times of observation, and any notes about the observations.
Data:The following graphs both show how long it took (in days) for fungal growth to appear on different combinations of termite castes. However, they have different ordering of termite combinations on the bottom depending on different hypotheses. The first is a prediction based on exposure to spores, the second on soldier inhibition of growth.
Hypothesis 1: The more exposure to spores, the fewer days it will take for fungal growth to appear.
Analysis for Hypothesis 1: • Because there is not a trend of a decreasing slope from least exposure (most time) to most exposure (least time), hypothesis 1 is not supported by the data.
Analysis of hypothesis 2: • Hypothesis 2 is almost fantabulously supported by the data. It shows that the higher proportion of soldiers, the longer it takes for fungal growth to begin. Only the single worker, which grew fungus more slowly than expected, confounds this hypothesis. Otherwise, we see a nice trend. ( Sort of like platforms in the seventies).
’03 research comparing proportion of workers with fungus to soldiers with fungus Workers: black line Soldiers: gray line
Tying in past research/ data • We found this skeleton in our closet, and brought it out because it shows that generally, workers grow fungus faster than soldiers. 60% of workers got fungus before soldiers all but three times, when it took the same amount of time.
Types of Fungus Observed: • Two types of fungus were observed growing in the test tubes. Filamentous fungus often grew much larger than slime-mold and had a fibrous, almost furry appearance. They were mostly white and greenish in color, however some of them appeared yellow, somewhat like bread mold. Slime-mold colonies were generally white and appeared as the name suggests, like slimy little blobs. Slime-mold was often the first type of fungus to appear in the tubes as pinhead-sized colonies. Although most of this type were whitish, some of the colonies were pinkish to red in color.
Conclusion To reach more stable conclusions, this experiment would have to be replicated many times. There is a high chance of error considering this experiment has only been done once. However, due to to the data, minus the one worker (and that could have been an experimenter malfunction), we conclude that Hypothesis 2 is more accurate.
Other factors: • Maybe we have to look at a crossover between hypothesis. Personally I think that the one worker would grow fungus more slowly than the five workers and one soldier (say the soldier inhibited the growth of fungus for one worker, there are still four times as many workers (with all their spore exposure) there. But it is difficult to look for combinations of hypotheses and it is better to isolate what is being studied.
Alas…… That is all for now… only the future will further support or reject our hypotheses… other Earthwatch crews, other days in the mangroves and around VIERS, other messy encounters with soldiers. That’s all folks!