Monday, August 3, 2009
Hey everyone yesterday was a long day with many new questions to be answered. We arrived at Lovell's Island around 10:00 AM, it was humid and hazy with an overcast sky. Bruce first brought us down to the beach to give us a background on what we would be looking for that day and what to expect. Next we began looking for Blue Mussell Shell's and perwinkles and scattering the beach looking for anything else we found that was interesting. We then walked down the beach and stopped to have lunch, when Bruce found a few very mysterious looking snail shells just laying in the sand. After lunch we walked through what used to be a salt marsh where identified the most invasive plant species known as a Pepper Weed which literally wraps around tress strangling them. On to the other side of the island to the tide pool where we looked for crabs although the tide was still a bit high, we saw Canadian Geese and a Spotted Sand Piper. We then went inland to look for snails and empty snail shells which we found many of, and we also saw the blackberries although most of them were still green. After searching for snails we still had time left to go back to the tide pools where it would be low tide and we could search for more creatures. A lobster was spotted the second time around at the tide pools, after that we met back the beginning of the island and talked about the day, and all of the many different creatures we came across, then it was back to Boston.
1. The Periwinkle crabs that we found early in the day had perfectly drilled holes in their shells, naturally being in this class we all wanted and needed to find out what those holes were from. After doing some research on predators the Periwinkles face I came to a creature called the Moon Snail. The Moon Snails has radula (tongue) with many rows of razor sharp teeth that will dril inot the shell slowly until the Moon Snail can get the prey out of their shell. They also have a liquid which when drilling helps to soften the outside of the shell its prey is in, because yesterday as we know the shell of a Periwinkle is tough to break. Moon snails can be found all over the world in intertidal or deep water. (Lessonsnips.com)
2. The mysterious snails as far as the empty shells go I still think they are the same snails we picked up ourselves. Just the simple brown and white lippid snails, there pictures are very similar, and when Bruce found the empty shells on the beach who knows how long they had been there. Without any nutrients and just laying on the hot sand with sun hitting them probably also had something to do with why they looked the way they did. I do not think there is anything that mysterious about them.
3. On our first stop to the tide pools Bruce wanted us to find a green crab and there were plenty of them. After researching the crabs I believe they can be identified as Asian Shore Crabs which are an Invasive species. This species of crab was first recorded in the U.S. at Townsend Inlet, in New Jersey in 1988. It is now very well established and abundant along the Atlantic intertidal coastline from Maine to North Carolina. (Biology.usgs.gov)
4. Differences in the living snail shells and dead shells I believe once again is just a simple answer. They are going to look different because one is dead and one is alive, one is breathing getting oxygen and allowing itself to obtain food and nutrients which will keep its exterior (shell) looking vibrant and full of color. The empty shells are not getting oxygen or nutrients so naturally there colors will be faded and the shells more brittle and broken.