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Background
information: Background
information: The Study: Sub-study: |
In October my Ecology of Atlantic Shores class was lucky enough to travel to Bermuda (!!!) and do research at the Bermuda Biology Research Station at St. George Bermuda. This page documents my small sub-project in Bermuda As I was interested in the use of Bee-tags to track snails at Spittle Pond, during a group exercise, I decided to tag some snails of my own. While at Spittle Pond I noticed T.muricatus a beautiful snail with tiny beads all over them. With their bumpy spires they blended into the jagged deeply pitted limestone and into the cavities of all sizes. Which is a possible reason for their habitat choice and shell morphology. I noticed no movement in the snails, so I decided to see whether they would moved overnight, and if so where would they go? Study site: Spittle pond
At spittle pond the area known as the "Checkerboard" was my study site.
Methods: 3 snails were tagged using blue Bee-Tags (small numbered labels) and superglue. This involved cleaning the backs of snails shells with alcohol swabs, and placing Bee-tags near (not over) the snail's operculum with super glue. The area of rock where a snail was found was also tagged with a Bee-Tag and superglue. Distance between the snail and the Bee-tagged rock were recorded so that movement away from this Bee-tag could be noted the following day. Distance was measured with a digital caliper. Numbers on tags were recorded. Due to limited time, only three snails were tagged. I called them snail one and two and three. Each were taken from a different wave gradient. Snail one was taken from a high wave action area, snail three from a sheltered area with no wave action, and snail 2 was taken from an intermediate area. Ibuttons were placed at the wave action area and at the relatively protected area. Snail with Bee-tag and Bee-Tag on rock (the little blue dots are the Bee-tags) Results and Observations: All snails were recovered in the morning. Snail three showed dramatic movement. It was found 18.79 cm away from original spot. It had moved down from the top of the rocks, toward the water. Snail 1 showed no sign of movement, and snail 2's movement was minimal (1.17 cm).
Table 1. Raw Data table of movement observed at Spittle Pond
Discussion: A comparable study to the one I briefly undertook at Spittle pond was conducted by Emson (2002). Researchers in the study attempted to determine the distribution and abundance of T.muricatus on Lee Stocking Island in Bahamas. They noted that with exception of animals very near the water’s edge, T.muricatus was inactive by day and on dry nights perhaps because of desiccation. Then Tropical Storm Erin passed over Lee Stocking Island and researchers noticed dramatic changes in T.muricatus behavior. They observed that many of the snail population up high in the intertidal became active at night during high humidity or rainfall. T.muricatus abundance also changed dramatically after the passage of Tropic Storm Erin. The rain also affected other behavior. Before the rain the T.muricatus were found all over and were inactive and no copulating pair were seen. Only animals being actively splashed by waves were moving. After rain large proportions of snails were in groups, or in pairs and were copulating (Emson et al, 2002). Not part of the original plan, but due to the new observations, Emson conducted a study very similar to my little project, to test the effects of moisture on T.muricatus movement. Eight snails were seen attached to a bush. They were each individually marked with numbered labels and their exact position was recorded. The site was revisited the next morning following a night of rain. Only three remained on the bush and all remaining had moved or changed position. Five of the snails could not be located and were presumed to have moved from the bush. The next day 11 snails on the rocks were also labeled this way using fingernail polish. Only four were found the following day. Two were upshore of the nearest possible point of origin and two were down shore. That night there had heavy rain and they concluded that this rain affected the snails movement (Emson et al, 2002). I found this study very interesting considering during our trip to Bermuda we too lived through a storm, Tropical Storm Nicole. Perhaps my observation of movement in T.muricatus was due to the affects of moisture and humidly due to the passage of the storm a day before. Graph 1 shows rainfall data for October 2004. On to my Study in Nahant Massachsetts where I tracked the movement of another periwinkle Littorina saxatlis or... On to the Discussion of the Nahant Project which considers more studies of movements relevant to this study and offers some insight into new improvements for better experimenting!
All information found on this site is for educational purposes only. Unless otherwise specified, all images are property of Kathryn Brown. For permission to use contact: Kathryn Brown (site creator) or Clark University Worcester, MA © 2004
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